[go: up one dir, main page]

WO2021086310A1 - Génération de modèles structuraux pour la fabrication additive d'un objet - Google Patents

Génération de modèles structuraux pour la fabrication additive d'un objet Download PDF

Info

Publication number
WO2021086310A1
WO2021086310A1 PCT/US2019/058366 US2019058366W WO2021086310A1 WO 2021086310 A1 WO2021086310 A1 WO 2021086310A1 US 2019058366 W US2019058366 W US 2019058366W WO 2021086310 A1 WO2021086310 A1 WO 2021086310A1
Authority
WO
WIPO (PCT)
Prior art keywords
data
build material
internal chamber
structural
target
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2019/058366
Other languages
English (en)
Inventor
Juan Manuel ZAMORANO ALVEAR
Wei Huang
Gary J. Dispoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hewlett Packard Development Co LP
Original Assignee
Hewlett Packard Development Co LP
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hewlett Packard Development Co LP filed Critical Hewlett Packard Development Co LP
Priority to PCT/US2019/058366 priority Critical patent/WO2021086310A1/fr
Publication of WO2021086310A1 publication Critical patent/WO2021086310A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/30—Auxiliary operations or equipment
    • B29C64/386—Data acquisition or data processing for additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y50/00—Data acquisition or data processing for additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/30—Process control
    • B22F10/38—Process control to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/80—Data acquisition or data processing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F5/10—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product of articles with cavities or holes, not otherwise provided for in the preceding subgroups
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
    • B29C64/10—Processes of additive manufacturing
    • B29C64/165—Processes of additive manufacturing using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • Additive manufacturing systems that generate three-dimensional objects on a layer-by-layer basis have been proposed as a potentially convenient way to produce three-dimensional objects.
  • Designers may design an object model specifying the shape and configuration of an object and to use additive manufacturing apparatus to generate the object according to that model.
  • Designers may evaluate structural properties of an object model before finalising their design.
  • Figures 1a-1d are simplified schematics of models for an object to be manufactured
  • Figure 2 is a flowchart of a method of defining print data for additive manufacture of an object
  • Figures 3a-3c illustrate target, constraint and load data relating to an object to be generated
  • Figures 4a-4c are simplified schematics of object model data and a structural model for a related object
  • Figure 5 is a further simplified schematic of a structural model for the object of Figure 4.
  • Figure 6 is a flowchart of a method of defining print data for an object and additive manufacture of the object
  • Figures 7a-7e are simplified schematics of object model data and structural models for an object
  • Figure 8 is a simplified schematic of additive manufacturing apparatus
  • Figure 9 is a simplified schematic of a processing module. DETAILED DESCRIPTION
  • Additive manufacturing techniques may generate a three-dimensional object through the solidification of a build material.
  • the build material may be powder-based and the properties of generated objects may depend on the type of build material and the type of solidification mechanism used.
  • build material is supplied in a layer-wise manner and the solidification method includes heating the layers of build material to cause melting in selected regions.
  • chemical solidification methods may be used.
  • Additive manufacturing systems may generate objects based on structural design data. This may involve a designer generating a three- dimensional model of an object to be generated, for example using a computer aided design (CAD) application.
  • the model may define the solid portions of the object.
  • the model data can be processed to generate slices of parallel planes of the model. Each slice may define a portion of a respective layer of build material that is to be solidified or caused to coalesce by the additive manufacturing system.
  • Figure 1a schematically shows a cross sectional representation of object model data delimiting an external profile 102 of a first example object to be generated by additive manufacture, which in this example is a cuboidal object.
  • the object model data delimits the external profile 102 of the object as an infinitely thin surface, and includes no further information relating to an internal configuration of the object.
  • Object model data of this type may be provided to an additive manufacturing apparatus which may generate the object (which may be considered an instance of the object defined by the object model data), according to the object model data, as a uniformly solid cuboid having a centre of mass towards its geometric centre.
  • the present disclosure relates to the definition of print data for an object to achieve a target parameter relating to a mass distribution of the object.
  • the methods disclosed herein permit, for given object model data defining an external geometry of the object, a target parameter such as the location of the centre of mass of an object to be specified, and print data to be generated so that the object has the same external profile as that defined in the original object model data, but achieves the target parameter.
  • the methods disclosed herein relate to automatic determination of a suitable construction of the object (e.g. the configuration of a structural frame and an internal chamber) in order to achieve the target parameter.
  • FIG. 1b schematically illustrates a first example of a structural model for the object.
  • the structural model includes a structural frame which defines the external profile 102 of the object.
  • the structural frame comprises a generally cuboidal shell wall 104 and a lump portion 106 offset from a centre of the object towards one side.
  • the structural frame corresponds to fused build material and may be associated within the structural model with a material having a first density, for example a density corresponding to the density of a plastics material which has fused from particulate (e.g. powder) form.
  • references herein to fusing relate to thermal fusing of build material, which results from heating the build material to a temperature above or close to its melting point so as to cause the build material (which may be powder or particles) to melt, coalesce and solidify upon cooling.
  • Fused build material may consolidate to occupy a smaller space than the same build material when unfused so that it has a higher first density than a lower second density of a volume of unfused build material (including the volume of interstices).
  • the degree of fusing can be varied between completely fused and completely unfused, for example by controlling the temperature to which the build material is heated during an additive manufacturing process. For example, in an additive manufacturing process which selectively applies a fusing agent that promotes heat transfer to a layer of build material, the amount of fusing agent to be locally applied may be varied to control the degree of local fusing. Similarly, where a detailing agent is used to cool build material and mitigate fusing, an amount of fusing agent to be locally applied may be varied to control the degree of fusing.
  • References herein to fused build material includes build material which is fused partially, which may have a lower density than completely fused build material.
  • An internal chamber 110 is defined within the structural frame 104, and is delimited by an internal wall of the structural frame including the lump portion 106.
  • the internal chamber 110 is modelled as unfused build material having the lower second density described above.
  • the unfused build material is captive within the structural frame, such that it cannot be discharged from the internal chamber without rupture of the structural frame.
  • the internal chamber 110 may be modelled as build material having a density different to that of the structural frame, which for example may be fused partially so as to have a lower density than that of the structural frame.
  • the shell wall 104 of the structural frame is of constant thickness. Accordingly, owing to the offset of the lump portion 106 to one side of the object and its relatively higher density compared to that of the density of the unfused build material in the internal chamber 110, a centre of mass 50 of the structural model (illustrated by a star) is determined to be offset from the geometric centre of the object.
  • the configuration of the structural frame and the internal chamber may be determined by a processing module based on predetermined modelling procedures and other criteria that may be specified (e.g. load data, constraint data).
  • the configuration of the object as determined for the object as described with respect to Figure 1b may be considered relatively simple in that it comprises an internal chamber without any support members spanning it (i.e. extending through it) and a lump portion. It may be that such a configuration is determined on the basis that the structural frame 104 can support a loading condition specified for the object despite not having any support members spanning the internal chamber 110.
  • Figure 1c schematically illustrates a further example of a structural model for the object described above with respect to Figure 1a.
  • the structural model of Figure 1c differs from that described above with respect to Figure 1b in that there is a larger lump portion 106 which in this example occupies a majority of the space defined within the shell wall 104 but remains offset to one side as a continuous portion.
  • the lump portion 106 is contiguous on three of its sides with the corresponding sides of the shell wall 104, and has an interface with an internal chamber 112 which occupies a remainder of the space within the shell wall 104.
  • the internal chamber 112 is modelled as an open void (i.e. empty of build material).
  • an open void may be formed following an additive manufacturing process to form the object by leaving build material at locations corresponding to the internal chamber 112 unfused, and subsequently removing the unfused build material from the internal chamber 112.
  • the unfused build material may be removed through an open channel 113 extending from the exterior profile of the object to the internal chamber 112, for example through an open channel 113 formed in the shell wall 104 as shown in Figure 1c.
  • the configuration of the structural model described with respect to Figure 1c is determined in preference to the configuration of Figure 1b in order to achieve a greater offset of centre of mass from the geometric centre of the object.
  • the target centre of mass could not be achieved if the internal chamber were to contain captive unfused build material, and a greater reduction in local mass at the respective side of the object is to be achieved, and which may be achieved by modelling as an open void.
  • Figure 1d schematically illustrates a further example of a structural model for the object described above with respect to Figure 1a.
  • the structural model of Figure 1d comprises a lump portion 106 as described above with respect to Figure 1c and an internal chamber 114 which occupies substantially the same space as the internal chamber 112 described above.
  • the structural model differs from that described above with respect to Figure 1c in that the structural frame comprises an internal support 108 which extends between external wall portions of the structural model through the internal chamber 114 (in particular, between portions of the shell wall 104 which define the external geometry of the object to be generated).
  • the internal support 108 comprises a cellular structure including a plurality of elongate cells.
  • the cellular structure may comprise a honeycomb structure.
  • Figure 1d shows two orthogonal cross-sectional views of the structural mode: with the upper view intersecting an elongate axis of some of the cells, and the lower view being normal to the elongate axes of the cells.
  • the cellular structure of the internal support 108 both extends through and partitions the internal chamber 114.
  • the structural frame is simulated (i.e. in the structural model) as fused build material having the relatively higher first density
  • the internal chamber 114 is simulated as unfused material having the relatively lower second density.
  • the internal chamber may be simulated as build material having a different density to that of the structural frame without being unfused, for example the internal chamber may be simulated as being fused partially. Accordingly, the centre of mass 50 of the object is once again offset towards one side of the object.
  • Figure 2 is a flowchart of a method 200 of defining print data and will be described, by way of example, with reference to the example object model data of Figure 1 a and the example structural models of Figures 1 b, 1 c and 1 d.
  • object model data delimiting an external profile of an object to be generated is received at a processing module.
  • the processing module may be provided as part of an additive manufacturing apparatus or remote from an additive manufacturing apparatus.
  • the processing module may be a combination of machine readable instructions and a processor to execute the machine readable instructions, as will be further described below.
  • target data specifying a target parameter relating to a mass distribution for the object to be generated is received at the processing module.
  • the target data may specify a target location of a centre of gravity 50 of the object.
  • other parameters relating to mass distribution may be specified, such as a target second moment of area or a target mass distribution of the object defining a plurality of locations within the object and associated mass parameters.
  • a target mass distribution may be specified by defining a target mass for each of a plurality of locations within the object, which may be sub-volumes of the object.
  • a target mass distribution may be specified by defining a target density for a sub-volume, or for a plurality of sub-volumes of the object.
  • a mass distribution may be specified for the whole or a part of the object, and multiple target parameters relating to the mass distribution may be specified as targets to be achieved by the generation of the structural model.
  • the target data may additionally include a total mass for the object (which does not, in isolation, relate to the mass distribution).
  • a structural model for the object is generated, by the processing module.
  • the structural model is automatically generated by the processing module to include a structural frame corresponding to fused build material of a first density and defining the external profile 102 of the object, and an internal chamber which either corresponds to an open void of the object (such as the internal chamber 112 of the structural model described with respect to Figure 1c) or an enclosed chamber of build material having a different second density (such as the internal chamber 110 of the structural model described with respect to Figure 1b), for example unfused build material or build material which is fused partially.
  • the target parameter may be such that if the object were manufactured as a solid volume consisting of fused build material (i.e. without an internal chamber as generated by the method) at a constant degree of fusing then the target parameter would not be achieved. In this way, the configuration of the structural frame and the internal chamber is determined to modify a mass distribution of the object.
  • the processing module determines a configuration of the structural frame and the internal chamber to achieve the target parameter, based on the object model data and the target data.
  • Properties of the structural frame may be defined and varied (for example, iteratively) to achieve the target parameter.
  • the location and interior boundary of a portion of the structural frame may be determined, such as the interior profile of an exterior wall (e.g. of a shell wall 104 as described above) or a lump portion.
  • the boundary of an adjacent internal chamber is determined. Determining the boundary may include determining both the size and shape of the boundary.
  • Generation of the structural model may be automatic, in that the configuration of the structural frame and the internal chamber is determined based on the object model data and the target data with reference to predetermined modelling procedures.
  • Determining the configuration of the structural frame may include automatically determining a configuration of an internal support of the structural frame which extends between external wall portions of the structural frame through an internal chamber, or partitions a plurality of internal chambers.
  • An external wall portion is to be understood as a portion of the structural frame defining a respective region of the external profile.
  • an internal support 108 in the form of a cellular structure may be determined, the cellular structure 108 extending from one portion of the shell wall 104 defining the external profile 102 of the object to another, and bisecting the internal chamber 114.
  • an internal support may be determined in any suitable form, and by reference to predetermined modelling procedures for determining a suitable configuration of the internal support.
  • suitable internal supports include an internal support member (e.g. a beam extending through an internal chamber), multiple internal support members in a repeating or non-repeating pattern, cellular structures such as that described above with respect to Figure 1 d, and a bifurcating tree-structure comprising a plurality of support members and a join or a plurality of joins between them, as will be described further below.
  • the modelling procedures may specify criteria for selecting between different types of internal supports, generating each type of internal support and determining properties of the internal support.
  • the modelling procedures may include procedures for automatically determining a thickness and direction of a support member based on the external profile for the object and the target data, or a cell size and wall thickness.
  • the configuration of the structural frame is iteratively determined based on an evaluation of the target parameter for a previous iteration of the structural frame.
  • the configuration of the structural frame may be determined indirectly, by directly determining a location and boundary of the internal chamber to achieve the target parameter, the structural frame being determined as the remaining portion of the object that corresponds to fused build material. It may be that the location and boundary of the internal chamber are iteratively determined based on an evaluation of the target parameter for a previous iteration of the internal chamber.
  • print data for the object is defined based on the structural model.
  • the print data may be defined to represent a plurality of slices of the structural model indicating which portions of a respective layer of build material are to be fused and which are to remain unfused, such that an object according to the structural model can be manufactured in a layer-by-layer manner based on the print data.
  • the print data determines the degree of fusing for any portion of build material, for example by indicating whether the build material is to be completely fused, partially fused to some degree, or completely unfused.
  • the print data may specify instructions relating to, for example, an amount of print agent and/or detailing agent to be ejected onto a layer of build material, or a laser power to be used, in order to control the degree of fusing.
  • the print data is interpreted or is processed in order to derive control data suitable for controlling a distribution of fusing agent and/or detailing agent, or for controlling a laser power, on portions of a layer of build material.
  • Figures 3a-3c schematically show a further example of object model data for an object and illustrate various data that may be provided, for example by a user, upon which a configuration of a structural frame and an internal chamber for the object may be generated.
  • Figure 3a schematically shows a cross-sectional representation of object model data delimiting an external profile 302 of a second example object to be generated by additive manufacture.
  • the object is a component part of a mechanical linkage, the object having a main body and three extension arms, each provided with an attachment point in the form of a hole 303 for interfacing with other parts of the linkage, for example pins of a rotary mechanism.
  • the object model data includes data delimiting the external profile 302 of the object, which includes the profile of the attachment points 303.
  • the object model data does not include data defining any configuration of an interior portion of the object.
  • a centre of mass 50 of the object can be readily predicted by simulation, as can a second moment of area and other properties relating to the uniform mass distribution of the object.
  • Target data may be provided, for example by a user, to specify a target centre of mass 55 which differs from the centre of mass 50 described above.
  • a user may define the object model data and the target data and provide both to be received at a processing module for generation of print data, for example by sending the object model data and the target data to an additive manufacturing apparatus including such a processing module.
  • a processing module may prompt a user to interactively provide target data upon receipt of object model data.
  • an additive manufacturing apparatus may prompt a user to provide user input specifying a target parameter, such as by specifiying a location of the centre of mass using an input device (e.g. a touch screen) on an additive manufacturing apparatus.
  • constraints may be specified for the generation of a structural frame and internal chamber. For example, it may be that selective definition of an internal chamber locally weakens an object to be manufactured relative to a uniformly solid object. By specifying constraints as to which portions of an object should be defined as fused build material in the structural model (i.e. part of the structural frame) rather than forming part of an internal chamber, structural integrity of the structural model may be improved.
  • Figure 3b schematically illustrates the definition of constraints 60 at each of the attachment points 303.
  • Constraints 60 may be defined in constraint data provided with the object model data.
  • the constraint data may indicate which features of a plurality defined in the object model data are to have constraints applied.
  • the object model data may define the external profile for the object as a plurality of discretely identified surfaces, such that the constraint data may specify which of the surfaces are to be treated as constraints by reference to an identifier for that surface.
  • Constraint data may be interactively provided by a user, for example in response to a prompt from an additive manufacturing apparatus or other device.
  • an additive manufacturing apparatus may prompt a user to specify which features within a representation of object model data are to be treated as constraints, and the user may select (for example using an input device such as a touch screen) those portions of the object to which constraints are to be applied.
  • Constraint data may be generated accordingly and supplied to a processing module for use in the generation of a structural model as will be further described below.
  • FIG. 3c schematically illustrates an example loading condition that the object may be to resist, for example including a plurality of forces 70 visualised as force vectors applied at each of the attachment points 303 (which in this example have been set as constraints 60 as described above with reference to Figure 3b).
  • a loading condition may be specified so that the generation of the structural model can take the loading condition into account when determining the configuration of the structural frame and internal chamber.
  • a loading condition may be defined in load data supplied to a processing module.
  • load data may be provided with the object model data.
  • load data may specify a load location on the external profile of the object, a load direction (e.g. a vector or torque direction) and a load magnitude (e.g.
  • Load data may specify a plurality of loads.
  • the load data may indicate which feature or features, of a plurality defined in the object model data, upon which the load is to be applied.
  • the load data may specify which surfaces of the object model data are to be loaded in a similar manner to the definition of constraints as described above.
  • Load data may be interactively provided by a user, for example in response to a prompt from an additive manufacturing apparatus or other device.
  • an additive manufacturing apparatus may prompt a user to specify which features within a representation of object model data are to be simulated as loaded, and the user may select (for example using an input device such as a touch screen) those portions of the object. Similarly, the user may then be prompted to specify a direction and magnitude of the load.
  • Load data may be generated accordingly and supplied to a processing module for use in the generation of a structural model as will be further described below.
  • Figures 4a-4c schematically illustrate an example structural model generated based on the object model data described above with respect to Figure 3a.
  • the structural model is generated based on the object model data, target data including a target centre of mass 55 and a target total mass, and constraint data indicating that constraints are to be applied at the attachment points 303.
  • Figure 4a schematically illustrates a representation of the object model data as received, including the external profile 302 of the object including the attachment points 303.
  • Figure 4b schematically illustrates a simulation of the object as a solid object of fused build material without any internal chamber, resulting in the determination of a centre of mass 50. As shown in Figure 4b, the target centre of mass 55 is offset from the determined centre of mass.
  • Figure 4c schematically illustrates a structural model of the object to achieve the target parameter of the target centre of mass 55.
  • the structural model is generated by applying constraints at the attachment points 303 which prevent any internal chamber that may be generated from extending within a predetermined zone around the constraint.
  • the configuration of the structural model is determined by iteratively determining the location and boundary of an internal chamber 410 of unfused build material (although in other examples the build material may be partially fused as indicated above).
  • an internal chamber may be simulated at a farthest position on an opposite side of the determined centre of mass 50 from the target centre of mass 55 without extending into the predetermined zone around any constraint, and the shape and size of the internal chamber may be iteratively adjusted based on predetermined modelling procedures and iterative evaluation of the location of the centre of mass 50.
  • the resultant structural model includes, in this example, a substantially triangular internal chamber 410 towards an opposite side of the main body of the object to the location of the target centre of mass 55.
  • the structural model may be generated to achieve the target parameter (e.g. of the target centre of mass 55) without also specifying a target total mass, or a target total mass may additionally be specified that is to be achieved when generating the structural model.
  • Figure 5 schematically illustrates a further example of a structural model for the object described above with respect to Figures 3a-3c and Figure 4.
  • the structural model is determined based on the object model data, target data including a target centre of mass and total mass, constraint data and load data as described above with respect to Figures 3a-3c.
  • the configuration of the structural model is determined by simulating a structural frame corresponding to fused build material, including a shell wall 504 which defines the external geometry of the object to be manufactured.
  • the structural frame additionally comprises a lump portion 506 which is disposed towards a side of the object where the target centre of mass 55 is defined, a plurality of constraint portions 565 generated around attachment points 303 associated with constraints defined by the constraint data, and an internal support 508 extending between portions of the structural frame through an internal chamber 512 simulated as an open void (being open via an open channel 513 provided in the shell wall 504).
  • predetermined modelling procedures for generating the structural model may specify an approach for generating the structural model.
  • a shell wall of sufficient strength thickness to be self-supporting may first be simulated, and then the constraint portions 565 generated around the constraints specified at the attachment portions 303.
  • the size of the constraint portions 565 may be determined based on the load data.
  • a lump portion 506 may then be generated to offset the mass distribution associated with the other portions of the structural frame.
  • the internal support 508 may be generated to extend between attachment points 303 and the lump portion so as to resist the loading condition specified in the load data.
  • the internal support 508 is generated as a tree-structure comprising a plurality of elongate members branching from one another at a plurality of joins.
  • the tree-structure may be generated according to predetermined modelling procedures that determine the generation of individual members, their placement and size based on a simulation of loads within the structural model.
  • the configuration of the structural model may be iteratively generated to target the target parameter of the location of centre of mass, together with the total mass of the object, whilst conforming to the constraints specified in the constraint data.
  • the configuration of the structural may be further iteratively adapted based on evaluating a resistance of the structural model to the loading condition (i.e. to ensure that the loading condition is adequately resisted, for example without undue strain beyond a threshold or excessive stress in the structural model beyond a threshold, such as a yield stress).
  • Figure 6 is a flowchart of an example method of defining print data for an object and additively manufacturing the object.
  • the method is conducted by a processing module of an additive manufacturing apparatus, such as the apparatus that will be described below with reference to Figure 8.
  • the method may be conducted by a processing module of a remote processing module (i.e. remote from any additive manufacturing apparatus), such as on a general purpose computer including instructions on a machine-readable medium for conducting the method.
  • object model data delimiting an external profile of the object is received at the processing module as described above with respect to Figure 2.
  • target data specifying a target parameter relating to mass distribution is received at the processing module as described above with respect to Figure 2.
  • the target data additionally includes a target total mass for the object.
  • load data relating to a load condition that the object is to resist is received at the processing module.
  • the load data may specify a load condition as described above with respect to Figure 3c.
  • constraint data relating to a portion of the object which is to be simulated in the structural model as fused build material having the first density and into which any internal chamber (for build material of a different second density or an open void) to be generated is prevented from extending.
  • the constraint data may specify a feature of the object (e.g. a region of the external profile of the object), such as a feature which is to interface with another part in use.
  • the constraint data may therefore indicate a surface region of the object, and a surrounding portion of the object may be simulated in the structural model as fused build material into which any internal chamber to be generated is prevented from extending.
  • the extent of the surrounding portion or zone of fused build material may be predetermined, as specified in either the constraint data or by predetermined modelling procedures upon which the generation of the structural model is based. Otherwise, the extent of the surrounding portion may be determined based on a simulation of loads at the respective feature where the constraint is applied, for example based on the load data received at block 622.
  • the processing module generates a structural model for the object including a structural frame corresponding to fused build material of a first density and defining the external profile of the object, and an internal chamber corresponding to an open void of the object or an enclosed chamber of build material having a different second density, for example a lower density corresponding to build material which is unfused or fused partially.
  • the configuration of the structural frame and the internal chamber is determined to achieve the target parameter while resisting the load condition specified by the load data and complying with the constraints derived from the constraint data.
  • the structural model may be generated automatically by reference to predetermined modelling procedures, as described above with reference to the examples of Figures 1a-1c, 4a-4c and 5.
  • any input received from or derived from a user upon which the configuration of the structural frame and the internal chamber is determined consists of no more than the object model data, target data and load data, and it may be that the configuration is automatically determined based on that input by reference to predetermined modelling procedures for determining a suitable configuration of the structural frame and the internal chamber.
  • print data is defined for additive manufacture of the object, as described above with reference to Figure 2.
  • the object is additively manufactured according to the determined structural model, for example by using an additive manufacturing apparatus which selectively fuses layer upon layer of build material.
  • Objects may be manufactured using a build material comprising a plastics material.
  • a print agent may be selectively applied to each layer of build material which promotes heat transfer to the build material from a radiant heat source, and a radiant heat source may be used to selectively fuse the build material accordingly.
  • plastics build material consolidates as it is fused and so regions of fused plastics build material achieve a higher density than regions of unfused material or build material that is fused partially. Such unfused plastics build material may be captive within the object.
  • unfused build material is optionally removed dependent on whether the structural model specifies that the internal chamber is to contain unfused material or be an open void.
  • the build material may be selectively fused using a laser or other directed radiant heat source, before removing unfused build material from around the object and applying the object to a global heat treatment that would fuse any remaining unfused build material.
  • regions of unfused material may be emptied of unfused material prior to such heat treatment, for example through an open channel as described above with reference to the examples.
  • Figure 7a schematically shows a cross-sectional representation of object model data, which in this example represents a bowling ball having an external profile 702.
  • Figure 7b-7e illustrate various target parameters relating to mass distribution which may be specified in target data to generate a structural model for the bowling ball (the object).
  • Figure 7b schematically illustrates target data received which specifies a target mass distribution.
  • the mass distribution is specified over a plurality of locations within the object (i.e. within its external profile) which are each associated with respective values of a mass parameter, which in this particular example is specified as a target density.
  • the plurality of locations are each sub-volumes of the object delimited by concentric spherical boundaries.
  • a central sub-volume 704 there is a central sub-volume 704, an intermediate sub volume 706 and an outer sub-volume 706.
  • the target parameters are specified so as to concentrate mass towards an outer region of the ball. Concentrating mass towards the outer region of the ball is understood to have the effect of increasing second moment of area (moment of inertia) with respect to a geometric centre of the bowling ball (which is inevitably intersected by a rolling axis of the bowling ball). An increased second moment of area may result in a higher angular momentum for a given rate of spin and given mass of the ball.
  • a relatively lower first density is specified for the central sub-volume 704, an intermediate second density is specified for the intermediate region, and a relatively higher third density is specified for the outer sub-volume 708.
  • a structural model for the object may be generated by a processing module by reference to predetermined modelling procedures.
  • a structural frame is generated comprising a shell wall 710 which defines the external profile of the object and bounds the outer sub-volume 708.
  • the structural frame further comprises an outer portion of the ball corresponding to the outer sub-volume 708 which is simulated as fused build material.
  • the structural frame further comprises portions within an intermediate portion of the ball corresponding to the intermediate sub-volume 706. In particular, it may be determined based on the predetermined modelling procedures that to achieve the target second density there should be a mix of portions having a higher first density and a lower third density.
  • an internal support is determined within the intermediate sub-volume 706 as a repeating pattern of support members with interstices between them that are filled with unfused build material. In other examples, it may be determined that to achieve the target second density the build material in the intermediate sub-volume should be fused partially (i.e. without support members).
  • the structural model is generated so that an internal chamber corresponding to unfused build material is defined in a central portion of the ball corresponding to the central sub-volume 704.
  • the internal chamber also extends into the interstices between the plurality of support members within the intermediate portion of the ball.
  • the structural model is generated to achieve the target parameter specified as target densities for the respective sub-volumes.
  • a target mass for each of a plurality of sub-volumes may be specified.
  • Figure 7d schematically illustrates a representation of the object model data for the bowling ball and a target parameter which is a target centre of mass for the object.
  • a target parameter of second moment of area is also specified (albeit this cannot be graphically illustrated).
  • a structural model for the object may be generated according to the methods disclosed herein, for example by determining a configuration of a structural frame as a thick outer shell wall 720 which defines the external profile 702 of the bowling ball and is integral with a lump portion 722 offset to one side of a central portion of the bowling ball.
  • the structural frame is simulated as fused build material having a first density
  • the internal boundary of the structural frame defines the boundary of an internal chamber 724 which is simulated as a region of captive unfused build material having a relatively lower second density.
  • a thickness of the shell wall 720 is iteratively adjusted to achieve the target second moment of area, whereas the size and location of the lump portion is iteratively adjusted to achieve the target centre of mass.
  • FIG. 8 schematically illustrates an example additive manufacturing apparatus 800 comprising a print bed for receiving build material, such as a plastics build material, a print head 804 moveable along an axis 805 over the print bed to apply a print agent onto the build material (for example to apply a print agent which promotes heat transfer from a radiant heat source) and a radiant heat source 806.
  • the additive manufacturing apparatus 800 further comprises a controller 810 to carry out a method of defining print data as described herein.
  • the controller 810 may be to carry out a method of defining print data and additively manufacturing an object according to the print data as described herein.
  • the controller 810 comprises a processing module 812, an example of which is described below with respect to Figure 9.
  • the controller 810 may be to carry out the methods described herein based on instructions encoded on a machine readable medium to be executed by a processor.
  • the controller 810 may be updated to include such instructions, for example by a software or firmware update.
  • Figure 9 schematically shows a processing module 812 comprising a machine readable medium 902 including instructions 904 executable by a processor 906 of the processing module 812 to carry out a method of defining print data as described herein.
  • the instructions may be to carry out a method of defining print data and additively manufacturing an object according to the print data as described herein, for example with reference to the flowcharts of Figure 2 and Figure 6..
  • Examples in the present disclosure can be provided as methods, systems or machine readable instructions, such as any combination of software, hardware, firmware or the like.
  • Such machine readable instructions may be included on a computer readable storage medium (including but is not limited to disc storage, CD-ROM, optical storage, etc.) having computer readable program codes therein or thereon.
  • the machine readable instructions may, for example, be executed by a general purpose computer, a special purpose computer, an embedded processor or processors of other programmable data processing devices to realize the functions described in the description and diagrams, for example by the controller 810 of the additive manufacturing apparatus 800.
  • a processor or processing apparatus may execute the machine readable instructions.
  • functional modules of the apparatus and devices may be implemented by a processor executing machine readable instructions stored in a memory, or a processor operating in accordance with instructions embedded in logic circuitry.
  • the term ‘processor’ is to be interpreted broadly to include a CPU, processing unit, ASIC, logic unit, or programmable gate array etc.
  • the methods and functional modules may all be performed by a single processor or divided amongst several processors.
  • Such machine readable instructions may also be stored in a computer readable storage that can guide the computer or other programmable data processing devices to operate in a specific mode.
  • Such machine readable instructions may also be loaded onto a computer or other programmable data processing devices, so that the computer or other programmable data processing devices perform a series of operations to produce computer-implemented processing, thus the instructions executed on the computer or other programmable devices realize functions specified by flow(s) in the flow charts and/or block(s) in the block diagrams.
  • teachings herein may be implemented in the form of a computer software product, the computer software product being stored in a storage medium and comprising a plurality of instructions for making a computer device implement the methods recited in the examples of the present disclosure.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Optics & Photonics (AREA)

Abstract

L'invention concerne une méthode de définition de données d'impression pour la fabrication additive d'un objet par fusion sélective de matériau de construction. Un modèle structural pour l'objet est généré, comprenant un cadre structural correspondant à un matériau de construction fusionné d'une première densité et une chambre interne (110) correspondant à un vide ouvert ou un matériau de construction ayant une seconde densité différente. La configuration du cadre structural et de la chambre interne (110) est déterminée sur la base de données de modèle d'objet qui délimitent un profil externe (102) de l'objet et des données cibles spécifiant un paramètre cible relatif à une distribution de masse cible (55) pour l'objet. L'invention concerne également un appareil de fabrication additive pour définir les données d'impression et pour fabriquer l'objet.
PCT/US2019/058366 2019-10-28 2019-10-28 Génération de modèles structuraux pour la fabrication additive d'un objet Ceased WO2021086310A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2019/058366 WO2021086310A1 (fr) 2019-10-28 2019-10-28 Génération de modèles structuraux pour la fabrication additive d'un objet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2019/058366 WO2021086310A1 (fr) 2019-10-28 2019-10-28 Génération de modèles structuraux pour la fabrication additive d'un objet

Publications (1)

Publication Number Publication Date
WO2021086310A1 true WO2021086310A1 (fr) 2021-05-06

Family

ID=75714624

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2019/058366 Ceased WO2021086310A1 (fr) 2019-10-28 2019-10-28 Génération de modèles structuraux pour la fabrication additive d'un objet

Country Status (1)

Country Link
WO (1) WO2021086310A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113370521A (zh) * 2021-05-25 2021-09-10 深圳市创想三维科技有限公司 模型打印方法、装置、计算机设备和存储介质
CN114670452A (zh) * 2022-03-31 2022-06-28 深圳市创想三维科技股份有限公司 支撑生成方法、装置、电子设备及存储介质

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160125494A1 (en) * 2009-05-19 2016-05-05 Cobra Golf Incorporated Method and system for sales of golf equipment
US9873229B2 (en) * 2013-11-21 2018-01-23 Hankookin, Inc. Three-dimensional object development
US20190152155A1 (en) * 2016-07-27 2019-05-23 Hewlett-Packard Development Company, L.P. 3d printing
US20190176395A1 (en) * 2016-05-12 2019-06-13 Hewlett-Packard Development Company, L.P. Post-processing in 3d printing systems
WO2019180466A1 (fr) * 2018-03-23 2019-09-26 The Plastic Economy Ltd Système et procédé de fabrication et d'optimisation des matériaux

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160125494A1 (en) * 2009-05-19 2016-05-05 Cobra Golf Incorporated Method and system for sales of golf equipment
US9873229B2 (en) * 2013-11-21 2018-01-23 Hankookin, Inc. Three-dimensional object development
US20190176395A1 (en) * 2016-05-12 2019-06-13 Hewlett-Packard Development Company, L.P. Post-processing in 3d printing systems
US20190152155A1 (en) * 2016-07-27 2019-05-23 Hewlett-Packard Development Company, L.P. 3d printing
WO2019180466A1 (fr) * 2018-03-23 2019-09-26 The Plastic Economy Ltd Système et procédé de fabrication et d'optimisation des matériaux

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113370521A (zh) * 2021-05-25 2021-09-10 深圳市创想三维科技有限公司 模型打印方法、装置、计算机设备和存储介质
CN114670452A (zh) * 2022-03-31 2022-06-28 深圳市创想三维科技股份有限公司 支撑生成方法、装置、电子设备及存储介质
CN114670452B (zh) * 2022-03-31 2024-05-17 深圳市创想三维科技股份有限公司 支撑生成方法、装置、电子设备及存储介质

Similar Documents

Publication Publication Date Title
JP7402013B2 (ja) トポロジー最適化による機械部品の設計
US10372110B2 (en) Controlled thin wall thickness of heat exchangers through modeling of additive manufacturing process
Lavery et al. A review of Computational Modelling of Additive Layer Manufacturing–multi-scale and multi-physics
Jin et al. Optimization of process planning for reducing material consumption in additive manufacturing
Jain et al. Effect of delay time on part strength in selective laser sintering
EP3551458B1 (fr) Fabrication additive
CN108885643B (zh) 用于增材制造的修改数据
JP2021059785A (ja) 積層造形法のための方法及び熱的構造体
Markl et al. Numerical investigations on hatching process strategies for powder-bed-based additive manufacturing using an electron beam
JP2007528810A (ja) 小直径流体流通孔を有する積層造形品およびその製造方法
US20220176450A1 (en) Apparatus and methods for optimization of powder removal features in additively manufactured components
US11733678B2 (en) Method for determining building instructions for an additive manufacturing method, method for generating a database with correction measures for controlling the process of an additive manufacturing method
AU2014206669A1 (en) Object production using an additive manufacturing process
WO2021086310A1 (fr) Génération de modèles structuraux pour la fabrication additive d'un objet
US20210062970A1 (en) Lattice Structures
CN105389435A (zh) 激光束与粉末颗粒光固耦合过程的介观模拟方法
Tang et al. Design of conformal porous structures for the cooling system of an injection mold fabricated by Additive Manufacturing Process
WO2018199938A1 (fr) Attribution de tâches de production d'objet
EP3600846B1 (fr) Procédé de fabrication d'enveloppes limites d'objets
Pakkanen Designing for additive manufacturing-product and process driven design for metals and polymers
CN110869188B (zh) 用于增材制造的物体模型中的嵌套分段
EP3810424A1 (fr) Structure en treillis autoportante
Saifullah et al. Cycle time reduction in injection moulding with conformal cooling channels
Miller et al. Monte Carlo simulation of three-dimensional nonisothermal grain-microstructure evolution: application to LENS rapid fabrication
CN113128082A (zh) 用于复合材料性能预测的细观模型的构建方法及系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19951126

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19951126

Country of ref document: EP

Kind code of ref document: A1