WO2025229271A1 - Bearing sample - Google Patents

Abstract

The invention relates to a bearing sample (70) comprising a member (71) made of a metal material or of a composite material, and comprising an elastomer layer (72) intended to at least partially receive the member (71) so as to form a contact interface (73), the bearing sample (70) being characterised in that the contact interface (73) comprises a fully adhesive contact surface (74), or comprises a first, adhesive contact surface (74) and a second contact surface (75) free of adhesive.

Description

Description

Title of the invention: Bearing sample

Technical Field

[0001] The present exposition relates to a step sample, a method, a computer program, and a device for determining a resistance to separation and a percentage of adhesion between components of such a step sample.

[0002] The bearing sample may correspond to a prototype of a stabilizer bar bearing in any type of vehicle, in order to limit vehicle roll. It is obvious to those skilled in the art that this bearing is not specifically limited to a single application, such as stabilizer bars for vehicles. On the contrary, this type of bearing could be used in various industrial and mechanical applications where a bond between metallic or composite components and an elastomer layer (a constituent element of the bearing) is required.

Previous technique

[0003] In a vehicle with axles, the two wheels of the same axle are generally connected by a stabilizer bar. The stabilizer bar, also called an anti-roll bar, is a suspension component of the vehicle. This bar acts as a spring that connects the two wheels of the same axle. It thus reduces body roll during cornering and dampens the deformations experienced by the suspension, in order to maintain optimal contact between the tires of said wheels and the road surface, ensuring maximum grip.

[0004] Each end of the stabilizer bar is thus fixed to the suspension triangle of a wheel, by means of ball-jointed links, while its central part is fixed to the chassis of the vehicle using at least two bearings.

[0005] These bearings are designed to allow the stabilizer bar to be fixed to the vehicle chassis while offering some flexibility, the stabilizer bar needing to be able to move slightly relative to the chassis.

[0006] For this purpose, the bearings generally comprise a metal flange and an elastic ring interposed between the stabilizer bar and the flange. This elastic ring, often made of elastomer, is thus generally placed around the stabilizer bar and then clamped by the flange, creating a compression that holds the ring in place. [0007] The adhesion between the elastic ring and the stabilizer bar plays a crucial role in the effective operation of the vehicle's suspension system. This adhesion is achieved through several mechanisms that come into play during the installation and operation of the part. First, during installation, the elastic ring is placed around the stabilizer bar (also called the component), where it is subjected to compression when clamped by the metal flange as explained above. This compression creates a frictional force between the ring and the bar, ensuring a firm adhesion between the two components. Second, this installation process involves the use of special glues or adhesives to reinforce the adhesion between the elastic ring and the stabilizer bar. These glues/adhesives are chosen for their adhesion properties to both the elastomer of the elastic ring and the material constituting the stabilizer bar.

[0008] However, if the elastic ring is not properly bonded to the stabilizer bar, it may deform or crack prematurely, which can lead to bearing failure. Furthermore, this insufficient bonding is likely to cause unwanted slippage or movement between the elastic ring and the stabilizer bar, generating significant noise.

[0009] Furthermore, if the protective coating typically applied to the stabilizer bar detaches due to poor bonding of the elastic bushing, blisters appear in the paint, which can then flake off, weakening the corrosion barrier normally provided by the paint. Road contaminants, particularly dust and water spray, can then penetrate under the paint at the bearing and cause localized corrosion of the stabilizer bar. This corrosion, combined with the stresses exerted by the bearing on the stabilizer bar, leads to paint deterioration right up to the elastic bushing.

[0010] As a result, in addition to this corrosion problem, this phenomenon causes significant noise, as the bearing then rubs against an area of damaged paint or even directly against the exposed and corroded stabilizer bar.

[001 1] For the sake of clarity, it is reiterated that noise refers to unwanted sounds or excessive friction noises between the bearing and the surface of the stabilizer bar. For a driver, the noise generated can be extremely bothersome for several reasons. Indeed, friction (sliding) or squeaking noises can make the journey uncomfortable for the driver. Experience Driving then becomes unpleasant, especially over long distances. This phenomenon is particularly noticeable during the winter months, when the polymer constituting the elastic ring hardens due to lower temperatures. Thus, as the polymer hardens, it increases the risk of friction or squeaking, thereby amplifying the noises perceived inside the vehicle.

[0012] Thus, an uncomfortable driving experience can then lead to a negative perception of the quality of the vehicle by the driver, and this can result in a decrease in customer satisfaction.

[0013] Thus, the adhesion between the elastic ring and the stabilizer bar is essential to ensure the proper functioning and safety of the vehicle's suspension system.

[0014] To guarantee the quality and reliability of the adhesion between the elastic ring and the stabilizer bar, equipment manufacturers use specific tests, one of the most common being the ASTM D429 test. This test is widely known in the industry for evaluating the adhesion properties of elastomeric materials with substrates, generally metallic, thus providing an indication of an adhesive's ability to maintain a durable bond between these two surfaces. It therefore allows equipment manufacturers, particularly those specializing in the manufacture of suspension systems, to verify the conformity of their products to the quality and safety standards established by the industry.

[0015] The ASTM D429 test generally involves the preparation of standardized samples (bearing samples) comprising the elastomer and a substrate, usually metallic, similar to those used in stabilizer bar bearings. These samples, whose dimensions differ from, or even significantly differ from, those of the stabilizer bar bearing intended for operational use, are then subjected to controlled test conditions, such as mechanical and thermal stresses. By measuring the forces required to separate the elastomer from the substrate, usually metallic, this test makes it possible to evaluate the effectiveness of the adhesive and the strength of the bond.

[0016] This test evaluates, for example, the peel strength of an adhesive between the substrate, generally metallic, and the elastomer material. In this case, the test involves applying a peel force to progressively separate the elastomer from the substrate, thus measuring the force required to cause the adhesive to fail. [0017] Current equipment manufacturers offer to perform these peel adhesion tests, but these are not carried out directly on actual vehicle components. In other words, these tests have drawbacks compared to the real-world conditions encountered by stabilizer bar bushings on a vehicle in operation. More specifically, in these tests, a metal plate is often coated with epoxy to simulate the metallic surface of the substrate. The sample is then prepared by applying the adhesive to the metal surface and attaching the elastomeric material to it, thus roughly mimicking the configuration of the elastic bushing and the stabilizer bar. A compression device is then used to exert uniform pressure on the sample. After this preparation phase, the actual test consists of applying a peel force to the sample to measure the peel resistance of the adhesive. The test results can vary, ranging from complete failure of the elastomer's cohesion to partial adhesion with cohesion failure or complete failure of adhesion. Therefore, the sample configuration does not replicate the actual stresses encountered by stabilizer bar bushings in a driving environment. Indeed, the forces and vibrations experienced by moving vehicle components can be far more complex and dynamic than what is simulated in the laboratory. Thus, while this peel adhesion test offers a standardized method for evaluating adhesive strength, it has limitations compared to the real-world operating conditions of a vehicle.

[0018] Other equipment manufacturers therefore prefer to perform these peel adhesion tests directly on the actual components, but these tests involve destructive and manual methods (with human operator intervention during the implementation of these tests). This means that the components being tested are damaged or destroyed during the process. This makes it impossible to reuse the components for further testing or for actual use in a vehicle, resulting in a waste of materials, resources, and cost.

[0019] It is therefore crucial to be able to guarantee the reliability and reproducibility of peel adhesion tests when evaluating vehicle suspension components. There is thus a need to implement an automated test that meets the objectives established by the ASTM D429 test, while avoiding destructive methods, and thereby overcoming the aforementioned drawbacks. Description of the invention

[0020] The present description relates to a bearing sample comprising a component made of a metallic or composite material, and comprising an elastomeric layer intended to receive at least partially said component so as to form a contact interface. The bearing sample is characterized in that the contact interface comprises a fully adhesive contact surface, or comprises a first adhesive contact surface and a second adhesive-free contact surface.

[0021] The bearing sample corresponds to a prototype of an assembly comprising a component surrounded by a bearing, used here for analysis and testing purposes in the context of improving the components of a bearing/component assembly intended to be operational thereafter. More specifically, the bearing sample is designed to simulate various load and motion conditions that a bearing may encounter in real-world applications. Of course, the term "bearing sample" may have different names known to those skilled in the art, as long as the sample as defined by the invention has the same characteristics. For example, a commonly used term to designate the bearing sample is bearing/component prototype.

[0022] The bearing sample, as defined herein, therefore comprises a component, either made of metallic or composite material, associated with an elastomeric layer. The metallic or composite component is intended to be in contact with the elastomeric layer in order to form a contact interface. What distinguishes this sample, more specifically and without limitation, is the nature of this contact interface.

[0023] The contact interface is then either entirely adhesive, meaning that the entire surface of the component in contact with the elastomeric layer is covered with an adhesive or glue (in the following, the term "adhesive" may be used interchangeably with "glue"). Alternatively, the contact interface may have a first adhesive surface and a second non-adhesive surface (without adhesive or glue). This means that only a portion of the component's surface is coated with adhesive. In this case, the adhesion between the component and the elastomeric layer is ensured by the first adhesive surface. [0024] Thus, this bearing sample has two possible configurations for its contact interface: either fully adhesive, or with a combination of an adhesive surface and a non-adhesive surface.

[0025] The creation of the second contact surface protects the sample, thus ensuring repeatable test conditions. More specifically, this practice ensures the reproducibility of the test by providing a precise reference point for applying the peel force and securely fixing the bearing sample during the test. This offers the advantage of gentler handling and better gripping of the bearing sample by the testing machines, thus ensuring optimal test repeatability without risk of damage to the elastomer layer. Therefore, the creation of the contact surface guarantees optimal test initiation under controlled conditions, contributing to reliable and consistent results throughout the testing process.

[0026] In the absence of the second contact surface and therefore when the surface is fully adhesive, a specific adhesive surface will be selected to allow said secure fixation of the bearing sample during the test.

[0027] According to some embodiments, the second contact surface is coated with a masking layer of the pad or tape type.

[0028] The masking layer is used to create a non-adhesive surface, distinct from the adhesive surface present on the first contact surface. The masking layer can be of the pad or tape type, generally made of materials compatible with the test environment, such as polymers. The masking layer is also designed to be easily applied and removed.

[0029] The pads are small pieces cut from a suitable material to form a barrier on the contact surface in place of adhesive/glue. The tapes, on the other hand, are strips of flexible material.

[0030] According to some embodiments, the adhesive contact surface is bonded by vulcanization or by bonding which is carried out hot or cold.

[0031] The adhesive contact surface of the bearing sample can be prepared by vulcanization or bonding, methods commonly used in industry to ensure a bond between the elastomer layer and the component. As a reminder, vulcanization is a chemical process in which the elastomer material is treated with vulcanizing agents such as sulfur, as well as heat. Alternatively, bonding can be used to attach the elastomer layer to the organ. In hot bonding, a hot-melt adhesive is applied to the adhesive contact surface and then heated to melt the adhesive, allowing it to penetrate the pores of both the organ and the elastomer. Once cooled, the adhesive hardens to form a bond between the two surfaces. Cold bonding, on the other hand, uses solvent-based or resin-based adhesives that polymerize at room temperature to form an adhesive bond.

[0032] According to some embodiments, the organ is made of steel, or of aluminium alloy, or of a hybrid material.

[0033] A hybrid material is defined as a material that combines two or more types of materials to exploit the advantages of each. Similarly, a composite material is defined as a structure consisting of two distinct phases: a matrix phase and a reinforced phase, such as carbon or glass fibers. Thus, while hybrid materials combine different materials to form a single structure, composite materials integrate distinct materials into a matrix to create a reinforced structure with specific properties.

[0034] For example, when the organ is made of composite material it may comprise layers of glass fibers alternating with layers of carbon fibers, and when the organ is made of hybrid material it may consist of a basic metallic structure, such as a steel core, which is then wrapped or coated with a fiber-reinforced polymer material.

This presentation also relates to a method for determining the resistance to separation and the percentage of adhesion between a component made of a metallic material or a composite material, and an elastomeric layer of a bearing sample as defined above, the method being characterized in that it comprises the following steps:

1) a step implementing an automated mechanical test, at ambient temperature or at a temperature between -40°C and 120°C, on the bearing sample by progressively applying a torsional peel force or in a radial direction at a predetermined angle relative to said contact interface of the bearing sample; and

2) a step of measuring the resistance to separation and the percentage adhesion between said organ and the elastomer layer as a function of the applied force.

[0035] Step 1) involves applying a controlled force to the bearing sample to simulate the stresses it would be subjected to under real operating conditions. This force can be applied torsionally or radially, depending on the test specifications. Once the force has been applied, step 2) involves measuring the resistance to separation between the component and the elastomer layer of the bearing sample, as well as measuring the percentage of adhesion between the component and the elastomer layer.

[0036] This adhesion percentage characterizes the quality of the adhesion between the elastomer and the organ in the bearing sample. For example, when the adhesion percentage is greater than 90% of the adhered surface (i.e., outside the adhesive-free contact interface), it corresponds to an adhered surface of 90% of the total surface area of the contact interface. In this case, the rupture occurs primarily within the elastomer, indicating strong adhesion between the elastomer and the organ. The elastomer then ruptures cleanly and uniformly, leaving a thin layer of elastomer on the organ.

[0037] According to another example, when the adhesion percentage is less than 10% of the bonded surface, the elastomer detaches from the component, revealing the underlying metal or composite surface. Traces of paint or adhesive may also be observed on the metal or composite surface, indicating detachment of the elastomer without significant adhesion to the component. This therefore suggests insufficient adhesion between the elastomer and the component, which can compromise the performance of the bearing/component assembly under real-world operating conditions.

[0038] Such a percentage of adhesion can be observed and evaluated during the application of peel force or following separation between the elastomer layer and the organ. To quantify the percentage of adhesion, the proportion of the surface area bonded between the elastomer and the organ that maintains a strong bond can be measured. This can be done, for example, by visually comparing the bonded surface area to the total surface area of the sample.

[0039] Of course, a person skilled in the art understands that the term "automatic" refers to a mechanical test that is carried out without direct intervention from a human operator. This ensures consistent and reproducible execution of the test. while allowing the operator to focus on other aspects, such as analyzing results.

[0040] According to certain embodiments, the predetermined angle is substantially equal to 90 degrees.

[0041] According to certain embodiments, the peeling force is applied progressively to induce a separation between said organ and the elastomer layer allowing the observation of a fracture face on said contact interface.

[0042] The peeling force can be applied gradually and in a controlled manner to induce separation between the organ and the elastomer layer, while allowing observation of the failure mechanisms at the contact interface between these two materials. This gradual increase in force creates increasing stresses on the contact interface between the elastomer and the organ, ultimately leading to said separation.

[0043] According to certain implementation modes, the fracture pattern is identified and/or the percentage of adhesion is determined by an execution of a machine learning algorithm.

[0044] The identification of the fracture pattern and the determination of the percentage of adhesion can be carried out using a machine learning algorithm. This algorithm is a computer tool that can analyze data and extract patterns or information from this data without being explicitly programmed to perform a specific task.

[0045] In this context, the machine learning algorithm can be trained from experimental data comprising observations, presented in two dimensions (2D) or three dimensions (3D), acquired by means such as vision cameras or laser profilometers, of fracture surfaces and percentage adhesion measurements under different test conditions. This data may include images or detailed descriptions of the observed fracture modalities, as well as quantitative measurements of the percentage adhesion.

[0046] Once the algorithm has been trained on this data, it can be used to analyze new observations of fracture facies and percentage adhesion measurements. The algorithm can then automatically identify the specific characteristics associated with different fracture facies, such as the presence of traces of paint or glue, adhesive break surface, etc. In addition, as indicated, it can further calculate the percentage of adhesion based on these characteristics.

[0047] The advantage of using a machine learning algorithm is its ability to identify complex patterns or relationships that can be difficult to detect manually. This allows for an objective analysis of the peel test results, which can contribute to a better understanding of the quality of adhesion between the elastomer and the organ in the bearing sample.

[0048] According to some embodiments, the component is a vehicle stabilizer bar.

[0049] The present exposition further relates to a computer program comprising instructions executable by a processor, which, when executed by the processor, implement the method of determining a resistance to separation and a percentage of adhesion as defined above.

[0050] The computer program can be coded in any programming language and take the form of source code, object code, or an intermediate form between source code and object code, such as a partially compiled form or any other desired form. Such a program can be stored on a computer-readable data medium.

[0051] The storage medium in question may be an internal or external hard drive, a USB flash drive, a CD-ROM, a memory card, or a cloud storage service. Of course, this list is not exhaustive and may include any other data storage medium known to a person skilled in the art and not mentioned herein.

[0052] The present disclosure further relates to a device for determining the resistance to separation and the percentage of adhesion between a component made of a metallic or composite material and an elastomeric layer of a bearing sample as defined above. The device comprises:

- application means configured to perform an automatic mechanical test, at ambient temperature or at a temperature between -40°C and 120°C, on the bearing sample by progressively applying a torsional peeling force or a force in a radial direction at a predetermined angle relative to said contact interface of the bearing sample; and measuring means configured to measure the resistance to separation and the percentage of adhesion between said organ and the elastomer layer as a function of the applied force.

[0053] This device is designed to perform controlled peel tests on bearing samples as defined above, thus enabling the analysis of their resistance to separation and their percentage of adhesion. In other words, this device is a testing machine that acts on the bearing sample by applying a controlled peel force and measuring the resistance to separation as well as the percentage of adhesion between the component and the elastomer layer.

[0054] Of course, a person skilled in the art understands that the term “automatic” refers to a mechanical test that is carried out without direct intervention from a human operator. This ensures consistent and reproducible execution of the test, while allowing the operator to focus on other aspects, such as analyzing the results.

[0055] According to some embodiments, the device includes computing means configured to identify a fracture face intended to be observed following a progressive application of the peeling force inducing a separation between said organ and the elastomer layer, and/or to determine the percentage of adhesion, by executing a machine learning algorithm.

[0056] The aforementioned features and advantages, as well as others, will become apparent from the following detailed description, examples of embodiments of the vehicle stabilizer bar bearing, and the proposed stabilizer assembly. This detailed description refers to the accompanying drawings.

The attached drawings are schematic and primarily intended to illustrate the principles of the presentation. In these drawings, from one figure to another, identical elements (or parts of elements) are identified by the same reference symbols.

[Fig. 1] Figure 1 is a perspective view of a stabilizing assembly;

[Fig. 2] Figure 2 is a perspective view of an example of a landing;

[Fig. 3A] and [Fig. 3B] Figures 3A and 3B schematically present two alternative configurations of a bearing sample according to the invention; [Fig. 4] Figure 4 schematically illustrates a determination method of a resistance to separation and a percentage of adhesion between two components of such a sample, according to an implementation method of the invention;

[Fig. 5] Figure 5 schematically illustrates a device for determining the resistance to separation and said percentage of adhesion between these two components according to an embodiment of the invention;

[Fig. 6] Figure 6 schematically illustrates an example of means of application of said device according to an embodiment of the invention; and [Fig. 7] Figure 7 schematically illustrates an example of a fracture face observed following the implementation of said means of application according to an embodiment of the invention.

Description of the methods of implementation and execution

[0057] To make the invention more concrete, a bearing sample is described in detail below, with reference to the accompanying drawings. It should be noted that the invention is not limited to this example.

[0058] As indicated above, the bearing sample corresponds to a prototype of an assembly comprising a metallic or composite component surrounded by a bearing. By way of example, the bearing in question may be designed for a stabilizer assembly 1 for a vehicle, for example, as illustrated in Figure 1. Of course, the vehicle is understood to mean any mobile structure, preferably an automobile such as a truck, car, or utility vehicle, designed for the transport of persons or goods.

[0059] Such a stabilizer assembly 1 is illustrated in Figure 1 solely by way of a non-limiting example of the application of the bearing sample. More specifically, the stabilizer assembly 1 comprises a stabilizer bar 10, solid or hollow, painted or unpainted, the central part of which 11 is equipped with two bearings 20. Such bearings 20 are intended to be fixed to the vehicle chassis, while the ends 12 of the stabilizer bar 10 are intended to be fixed to parts of the vehicle integral with each wheel of the same axle, in particular the suspension triangle of each wheel of the axle.

[0060] The bearings 20 can be solid or in the form of two split bearings intended to be assembled together. More specifically, a solid bearing is characterized by a unitary mechanical structure without slots, openings or significant discontinuities in its structure whereas a split bearing (or half-bearing) has a mechanical structure with an opening or slot, allowing it to be installed around the chassis and assembled with another split bearing or removed from around the chassis.

[0061] By way of example, when the bearing 20 is solid, it can completely enclose the stabilizer bar 10 along an axis A corresponding to the direction of extension of the stabilizer bar 10 when the bearing 20 is mounted. Conversely, when the bearing 20 is split, it can only enclose the stabilizer bar 10 on one side of the axis A, while another split bearing 20 encloses the stabilizer bar 10 on the other side of the axis B.

[0062] In this example, the bearing 20 is solid and has a general U-shaped form, but alternatively, it may be cylindrical, conical, or elliptical. Since the flange portion 30 can also conform to the shape of the bearing 20, its cavity can be cylindrical, conical, or elliptical so as to completely surround the stabilizer bar 10.

[0063] In this case, the flange portion 30 corresponds to a flange 30. Conversely, the flange portion 30 can be semi-cylindrical, semi-conical, or semi-elliptical in shape when the bearing 20 is split and thus partially surrounds the stabilizer bar 10. In this latter case, the flange portion 30 comprises first and second flange elements 30 configured to be joined against each other. Each flange element 30 then comprises a cavity portion, each lined with the elastomeric coating 60 or elastomeric layer 60, together forming said cavity of the flange portion 30.

[0064] It should be noted that the elastomer layer 60 of the bearing 20 intended to be in direct contact with the stabilizer bar 10 may have a cylindrical shape.

[0065] In the following description and for the sake of brevity, a “bearing” represents either a solid bearing or a split bearing. In other words, the tests performed on the bearing sample may lead to the final production of either a solid bearing or a split bearing.

[0066] Such a bearing sample 70, as illustrated in Figure 3A, represents an important component for evaluating the bond between metallic or composite materials and an elastomeric layer. More specifically, this bearing sample comprises a component 71 constituting a prototype of at least a portion of the bar stabilizer 10, and can be made of steel, aluminum alloy or a hybrid material which combines two or more types of materials to exploit the advantages of each.

[0067] In addition, the bearing sample 70 is provided with an elastomer layer 72, corresponding to the prototype of the elastomer layer 60 of the bearing 20. This elastomer layer 72, just like that of the bearing 20, is arranged so as to receive at least partially the organ 71, thus forming a contact interface 73.

[0068] The contact interface 73 has an adhesive contact surface 74 covering its entire surface, or a combination of a first adhesive contact surface 74 and a second adhesive-free contact surface 75, as illustrated in Figure 3B. More specifically, the second contact surface 75 is covered with a masking layer 76, such as a pad or tape, for example. In contrast, the (first) adhesive contact surface 74 is bonded to the component 71 by vulcanization or by bonding, whether hot or cold.

[0069] Thus, the bearing sample 70 represents a specific assembly designed to evaluate the adhesion between the metallic or composite material component and the elastomer layer. By combining the properties of these two components, this sample offers a faithful representation of the conditions encountered in the final configuration of the stabilizer bar 10, thus enabling precise and realistic tests on the quality of adhesion.

[0070] The step sample 70 is then used to implement a process 80 for determining a resistance to separation and a percentage of adhesion between the organ 71 and the elastomer layer 72 of the step sample 70.

[0071] More specifically, this percentage of adhesion characterizes the quality of the adhesion between the elastomer 72 and the component 71 in the bearing sample 70. For example, when the percentage of adhesion is greater than 90% of the adhered surface, it corresponds to a remaining adhered surface of 90% of the total initially adhesive surface of the contact interface 73. In this case, the break occurs mainly within the elastomer 72, which indicates strong adhesion between the elastomer 72 and the component 71. The elastomer 72 then breaks cleanly and uniformly with a thin layer of elastomer 72 remaining on the component 71.

[0072] According to another example, when the percentage of adhesion is less than 10% of the adhered surface, the elastomer 72 detaches from the organ 71, revealing the metallic or composite surface underneath. Traces of paint or glue may also be observed on the metallic or composite surface, indicating detachment of the elastomer 72 without significant adhesion to the component 71. This therefore suggests insufficient adhesion between the elastomer 72 and the component 71, which may compromise the performance of the bearing/component assembly under real operating conditions.

[0073] To this end, Figure 4 presents a flowchart describing the different steps of said process of 80.

[0074] The process 80 begins with a step E1 implementing a mechanical, automatic and repeatable test on the bearing sample 70 by progressively applying a torsional peeling force or in a radial direction at a predetermined angle relative to the contact interface 73, for example an angle substantially equal to 90 degrees.

[0075] The peeling force can optionally be applied gradually and in a controlled manner, for example at a speed of 10 mm/min (or millimeters per minute), in order to induce separation between the component 71 and the elastomer layer 72, while allowing observation of a fracture surface at the contact interface 73 between these two components. Such an observation can be presented in two dimensions (2D) or in three dimensions (3D) and can be acquired by means such as vision cameras or laser profilometers.

[0076] The process 80 continues with the implementation of a step E2 for measuring the resistance to separation and the percentage of adhesion between said component 71 and the elastomer layer 72 as a function of the applied force. The percentage of adhesion can then be observed and evaluated. To quantify the percentage of adhesion, the proportion of the surface area bonded between the elastomer 72 and component 71 that maintains a solid bond can be measured. This can be done, for example, by visually comparing the bonded surface area to the total surface area of the sample.

[0077] However, it is possible to identify the fracture surface and also to determine the percentage of adhesion using other techniques. To this end, the method 80 optionally includes a step E3 for identifying the fracture surface and/or determining the percentage of adhesion by running a machine learning algorithm. By way of example, the machine learning algorithm can be trained from experimental data including fracture surface observations and percentage of adhesion measurements in different test conditions. This data may include images or detailed descriptions of the observed failure patterns, as well as quantitative measurements of the percentage of adhesion.

[0078] Once the algorithm has been trained on this data, it can be used to analyze new observations of fracture surfaces and percentage adhesion measurements. The algorithm can then automatically identify the specific characteristics associated with different fracture surfaces, such as the presence of traces of paint or glue, the adhesive fracture surface, etc. Furthermore, as indicated, it can also calculate the percentage adhesion based on these characteristics. These new observations and analyses performed by the algorithm can be automatically integrated into a database to which the algorithm is connected, thereby increasing the reliability of its future analyses.

[0079] The advantage of using a machine learning algorithm is its ability to identify complex patterns or relationships that can be difficult to detect manually. This allows for an objective analysis of the peel test results, which can contribute to a better understanding of the quality of adhesion between the elastomer and the organ in the bearing sample.

[0080] Figure 5 illustrates a device 90 for determining the resistance to separation and the percentage of adhesion between the component 71 and the elastomer layer 72 of the step sample 70. More specifically, this device 90 is designed to perform controlled peel tests on step samples 70, thus allowing analysis of their resistance to separation and their percentage of adhesion. This device enables the implementation of the process 80.

[0081] For this purpose, the device 90 includes application means 91 configured to carry out an automatic mechanical test on the sample 70 by progressive application of the torsional peel force or in a radial direction according to said predetermined angle with respect to the contact interface 73.

[0082] The device 90 further includes measuring means 92 configured to measure the resistance to separation and the percentage of adhesion between said organ 71 and the elastomer layer 72 as a function of the applied force.

[0083] Finally, the device 90 may include computing means 93 configured to identify a fracture surface intended to be observed following an application progressive peeling force inducing separation between said organ 71 and elastomer layer 72, and/or determine the percentage of adhesion, by an execution of said machine learning algorithm.

[0084] Of course, the calculation means 93, the application means 91, and the measurement means 92 can be implemented by various technical means well known to those skilled in the art. Figure 6 illustrates a non-limiting example of the application means 91 that those skilled in the art can implement. In this example, and as illustrated, the bearing sample 70 is subjected to a torsional peeling force 100, where the force is applied rotationally around the contact interface of the bearing sample 70, but also to said peeling force in a radial direction 101, where the force is applied perpendicular to this interface.

[0085] The peeling force can be applied progressively by the application means 91 on the sample 70 to induce a separation between said organ 71 and the elastomer layer 72 allowing the observation of a fracture face on said contact interface 73.

[0086] Such a fracture surface is illustrated in Figure 7. More specifically, in this example, the contact interface 73 is fully adhesive due to the application of an adhesive. The contact interface 73 has residues 77 of elastomer 72 in a first zone Z1 and in a second zone Z2 of the contact interface 73. The fracture occurs primarily within the elastomer, indicating strong adhesion between the elastomer 72 and the component 71. The elastomer 72 then breaks cleanly and uniformly, leaving a thin layer of elastomer (residue) 77 remaining on the component 71.

[0087] The contact interface 73 further comprises a third zone Z3 free of elastomer residue 72, indicating detachment of the elastomer without significant adhesion to the component 71. Thus, the elastomer 72 has completely detached from the component 71, thereby revealing the metallic or composite surface beneath. Traces of paint or glue can also be observed on the metallic or composite surface. This therefore suggests insufficient adhesion between the elastomer 72 and the component 71.

[0088] Although the present invention has been described with reference to specific embodiments, it is evident that modifications and changes can be made to these examples without departing from the general scope of The invention as defined by the claims. In particular, individual features of the various embodiments illustrated/mentioned can be combined in additional embodiments. For example, when a bearing as the final product is of the split type, a person skilled in the art can perform the test sequentially on the bearing sample suitable for this purpose (in other words, on split-type bearing samples) without departing from the scope of the invention. Therefore, the description and drawings should be considered in an illustrative rather than a restrictive sense.

[0089] It is also evident that all the characteristics described with reference to a process are transferable, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device are transferable, alone or in combination, to a process.

Claims

Demands [Claim 1] Bearing sample (70) comprising a component (71) made of a metallic material or of a composite material, and comprising an elastomeric layer (72) intended to receive at least partially said component (71) so as to form a contact interface (73), the bearing sample (70) being characterized in that the contact interface (73) comprises a contact surface (74) that is entirely adhesive, or comprises a first adhesive contact surface (74) and a second adhesive-free contact surface (75). [Claim 2] Bearing sample (70) according to claim 1, wherein the second contact surface (75) is coated with a masking layer of the pellet or tape type. [Claim 3] Bearing sample (70) according to claim 1 or 2, wherein the adhesive contact surface (74) is bonded by vulcanization or by bonding which is carried out hot or cold. [Claim 4] Bearing sample (70) according to any one of the preceding claims, wherein the component (71) is made of steel, or of aluminum alloy, or of a hybrid material. [Claim 5] A method (80) for determining a resistance to separation and a percentage of adhesion between a component (71) made of a metallic material or a composite material, and an elastomeric layer (72) of a bearing sample (70) according to any one of claims 1 to 4, the method (80) being characterized in that it comprises the following steps: 1) a step (El) implementing an automatic mechanical test, at ambient temperature or at a temperature between -40°C and 120°C, on the bearing sample (70) by progressively applying a peel force torsional or in a radial direction at a predetermined angle with respect to said contact interface (73) of the bearing sample (70); and 2) a step (E2) of measuring the resistance to separation and the percentage of adhesion between said organ (71) and the elastomer layer (72) as a function of the applied force. [Claim 6] Method (80) according to claim 5, wherein the predetermined angle is substantially equal to 90 degrees. [Claim 7] Method (80) according to claim 5 or 6, wherein the peeling force is applied progressively to induce a separation between said member (71) and the elastomer layer (72) allowing the observation of a fracture face on said contact interface (73). [Claim 8] Method (80) according to claim 7, wherein the fracture face is identified and/or the percentage of adhesion is determined by an execution of a machine learning algorithm. [Claim 9] Method (80) according to any one of claims 5 to 8, wherein the component (71) is a vehicle stabilizer bar (10). [Claim 10] A computer program comprising instructions executable by a processor, which, when executed by the processor, implement the method (80) for determining a resistance to separation and a percentage of adhesion according to any one of claims 5 to 9. [Claim 11] Device (90) for determining a resistance to separation and a percentage of adhesion between a component (71) made of a metallic material or a composite material, and an elastomeric layer (72) of a step sample (70) according to any one of claims 1 to 4, the device (90) comprising: - application means (91) configured to perform an automatic mechanical test, at ambient temperature or at a temperature between -40°C and 120°C, on the bearing sample (70) by progressively applying a torsional peeling force or in a radial direction at a predetermined angle with respect to said contact interface (73) of the bearing sample (70); and - measuring means (92) configured to measure the resistance to separation and the percentage of adhesion between said organ (71) and the elastomer layer (72) as a function of the applied force. [Claim 12] A device (90) according to claim 11, comprising computing means (93) configured to identify a fracture surface to be observed following a progressive application of peel force inducing separation between said component (71) and the elastomer layer (72), and/or to determine the percentage of adhesion, by executing a machine learning algorithm.