Contact stiffness curve acquisition method, device, equipment and medium

Abstract

The present invention discloses a method, apparatus, device, and medium for obtaining a contact stiffness curve, comprising: first obtaining first modal data corresponding to a plurality of preset pressures; then performing modal simulation to obtain the contact stiffness corresponding to the plurality of preset pressures; and finally fitting the contact stiffness corresponding to the plurality of preset pressures to obtain a contact stiffness curve. The present invention provides a method for rapidly obtaining a contact stiffness curve between a supported object and a shim under different preset pressures. By combining simulation and testing, the dynamic characteristics of the interface between the object and the shim can be quickly and accurately determined.

Description

Technical Field

[0001] The present invention relates to the technical field of contact stiffness, and in particular to a method, device, equipment and medium for obtaining a contact stiffness curve. Background Art

[0002] Washers are usually placed under objects and serve as pressure-bearing and force-transmitting components of the objects. They have the function of reducing the outward transmission of vibration forces and preventing the inward transmission of vibration forces. They can also be used for leveling machine tools and are the most basic installation accessories in equipment installation.

[0003] When performing dynamic simulation analysis on a rack structure with shims, the interface between the object and the shim cannot be regarded as a rigid connection, nor can it be simply considered as contact with a friction coefficient. Instead, it is manifested as a flexible connection with isotropic stiffness. A common practice is to use a spring to represent the connection form of the interface and assign isotropic stiffness data to it to establish a dynamic model. Therefore, the rationality of the spring stiffness data directly affects the accuracy of the simulation results.

[0004] Many factors can influence the stiffness data at the interface between an object and a shim, including the mating surface material, contact surface dimensions, surface roughness, and preset pressure. Regarding the preset pressure, the prior art does not provide a method for obtaining a contact stiffness curve using the preset pressure as an influencing factor. Summary of the Invention

[0005] Based on this, it is necessary to provide a contact stiffness curve acquisition method, device, equipment and medium to solve the problem that the prior art does not provide a contact stiffness curve with a preset pressure as an influencing factor.

[0006] A method for obtaining a contact stiffness curve for a joint surface between a supported object and a shim, the method comprising:

[0007] Step S1, obtaining first modal data corresponding to a plurality of preset pressures, wherein the first modal data corresponding to the target preset pressure is modal data obtained by performing a modal test on the supported object when the shim is in a target support position and the pressure applied thereto is the target preset pressure; the target preset pressure is any one of the plurality of preset pressures, and the preset pressure is the positive pressure exerted by the supported object on the shim;

[0008] Step S2, performing modal simulation to obtain contact stiffnesses corresponding to the multiple preset pressures, wherein the contact stiffness corresponding to the target preset pressure is: constructing a simulated shim corresponding to the shim and a simulated supported object corresponding to the supported object through a simulation system; when the simulated shim is located at a position corresponding to the target support position and the pressure exerted on the simulated shim is the target preset pressure, performing modal analysis on the simulated supported object to obtain second modal data; by adjusting the second modal data until the error between the second modal data and the first modal data is less than a preset value, obtaining the contact stiffness between the simulated shim and the simulated supported object;

[0009] Step S3: fitting the contact stiffnesses corresponding to the plurality of preset pressures to obtain a contact stiffness curve.

[0010] In one embodiment, step S2 includes:

[0011] Step S21, under the condition that the pressure exerted on the simulated support by the simulated shim is set to a target preset pressure, dynamically adjusting the contact stiffness between the simulated shim and the simulated support by approximating the second modal data to the first modal data, and performing modal simulation on the simulated support;

[0012] In step S22 , the contact stiffness obtained when the error between the second modal data and the first modal data is less than a preset value is used as the contact stiffness corresponding to the target preset pressure, so as to obtain the contact stiffnesses corresponding to the multiple preset pressures respectively.

[0013] In one embodiment, the modal data includes vibration modes in a preset three-dimensional coordinate system. Step S21 includes:

[0014] Step S21A: determining a target dimension based on the second modal data corresponding to the target preset pressure; wherein the preset three-dimensional coordinate system includes three dimensions, the target dimension is one of the three dimensions, and the difference between the amplitude of the target dimension and the amplitudes of the other two dimensions is greater than a preset amplitude;

[0015] Step S21B, dynamically adjust the contact stiffness between the simulated pad and the simulated supported object in the target dimension, and perform modal simulation so that the vibration mode of the second modal data in the target dimension approaches the vibration mode of the first modal data in the target dimension.

[0016] In one embodiment, the modal simulation includes: rigid body modal simulation and flexible body modal simulation, step S21 includes:

[0017] Step S21a, dynamically adjusting the contact stiffness between the simulated shim and the simulated supported object, and performing rigid body modal simulation on the supported object so that the preset low-order second modal data obtained by the simulation approaches the preset low-order first modal data under the target preset pressure;

[0018] Step S21b, when the difference between the preset low-order first modal data obtained by the simulation and the preset low-order second modal data at the target preset pressure is less than the preset value, dynamically adjust the contact stiffness between the simulated pad and the simulated supported object, and perform flexible body modal simulation on the supported object, so that the preset high-order second modal data obtained by the simulation approaches the preset high-order first modal data at the target preset pressure.

[0019] In one embodiment, the number of the actual shims is at least 3, and before step S1, the following steps are further included:

[0020] Step A1, constructing a simulated fixed hinge in the simulation system;

[0021] Step A2: connecting the simulated shim to the simulated supported object at the supporting position using the simulated fixed hinge, and obtaining the bearing force output by the simulated fixed hinge, wherein the positions and quantities of the simulated fixed hinge and the simulated shims correspond one to one;

[0022] Step A3: Determine whether the difference in the bearing pressure output by any two of the multiple simulated fixed hinges is less than or equal to a preset difference. If the difference in the bearing pressure is greater than the preset difference, jump to step A4. If the difference in the bearing pressure output by any two simulated fixed hinges is less than or equal to the preset difference, jump to step A5.

[0023] Step A4, adjusting the support position of each simulation shim and jumping to step A2;

[0024] Step A5: setting the adjusted support position of each simulation shim as the target support position.

[0025] In one embodiment, step S1 includes:

[0026] Step S1a, placing the shims at the target support positions so that the pressure on each shim is less than or equal to a preset difference, and adjusting the target preset pressure;

[0027] Step S1b: Control the vibration component to transmit vibration to the supported object at one or more vibration positions, obtain modal data of the supported object at the one or more vibration positions as the first modal data corresponding to the target preset pressure, so as to obtain the first modal data corresponding to the multiple preset pressures respectively.

[0028] In one embodiment, after step S3, the method further includes:

[0029] Step S4, adjusting the pressure transmitted by the supported object to the shim to a test pressure, and performing a modal test on the supported object to obtain third modal data of the supported object under the test pressure;

[0030] Step S5, matching an equivalent contact stiffness corresponding to the test pressure from the contact stiffness curve, setting the contact stiffness to the equivalent contact stiffness under modal simulation in a simulation system, and obtaining fourth modal data of the supported object under the test pressure;

[0031] Step S6, determining whether an error between the third modal data and the fourth modal data is less than a preset value; if the error between the third modal data and the fourth modal data is less than the preset value, jumping to step S7; if the error between the third modal data and the fourth modal data is greater than or equal to the preset value, jumping to step S1;

[0032] Step S7: determining whether the contact stiffness curve is accurate.

[0033] A contact stiffness curve acquisition device, comprising:

[0034] A real modal test module is used to obtain first modal data corresponding to multiple preset pressures, wherein the first modal data corresponding to the target preset pressure is the modal data obtained by performing a modal test on the supported object when the shim is in the target support position and the pressure it is subjected to is the target preset pressure; the target preset pressure is any one of the multiple preset pressures, and the preset pressure is the positive pressure generated by the supported object on the shim;

[0035] a modal simulation module for performing modal simulation to obtain contact stiffnesses corresponding to the multiple preset pressures, wherein the contact stiffness corresponding to the target preset pressure is: constructing a simulated shim corresponding to the shim and a simulated supported object corresponding to the supported object through a simulation system; when the simulated shim is located at a position corresponding to the target support position and the pressure applied to the simulated shim is the target preset pressure, performing modal analysis on the simulated supported object to obtain second modal data; and obtaining the contact stiffness between the simulated shim and the simulated supported object by adjusting the second modal data until the error between the second modal data and the first modal data is less than a preset value;

[0036] The fitting module is used to fit the contact stiffnesses corresponding to the plurality of preset pressures to obtain a contact stiffness curve.

[0037] A computer-readable storage medium stores a computer program, which, when executed by a processor, causes the processor to perform the steps of the contact stiffness curve acquisition method.

[0038] A contact stiffness curve acquisition device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the above-mentioned contact stiffness curve acquisition method.

[0039] The present invention provides a method, apparatus, device, and medium for obtaining a contact stiffness curve. The method first obtains first modal data corresponding to multiple preset pressures; then performs modal simulation to obtain the contact stiffness corresponding to each of the multiple preset pressures; and finally, fits the contact stiffness corresponding to each of the multiple preset pressures to obtain a contact stiffness curve. The present invention provides a method for rapidly obtaining a contact stiffness curve between a supported object and a shim under different preset pressures. By combining simulation and testing, the dynamic characteristics of the interface between the object and the shim can be quickly and accurately determined. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] in:

[0042] Figure 1 Schematic diagram of the process of obtaining the contact stiffness curve in the first embodiment;

[0043] Figure 2 A schematic diagram of a process for finding a target support position when the external force on each shim is the same in one embodiment;

[0044] Figure 3 A schematic diagram of a target support position of a shim in one embodiment;

[0045] Figure 4 is a schematic diagram of the bed gravity load exerted on three shims at target support positions in one embodiment;

[0046] Figure 5 is a first schematic diagram of a data processing system in one embodiment;

[0047] Figure 6 is a schematic diagram of modal data in one embodiment;

[0048] Figure 7 A first schematic diagram of adjusting the contact stiffness between at least three virtual shims and a virtual object in one embodiment;

[0049] Figure 8 Schematic diagram of the changes between the virtual shim and the virtual object under the third-order constraint mode;

[0050] Figure 9 A second schematic diagram of adjusting the contact stiffness between at least three virtual shims and a virtual object in one embodiment;

[0051] Figure 10 A schematic flow chart of a method for obtaining a contact stiffness curve in the second embodiment;

[0052] Figure 11 Schematic diagram of the structure of a contact stiffness curve acquisition device in one embodiment;

[0053] Figure 12 A structural block diagram of a contact stiffness curve acquisition device in one embodiment. DETAILED DESCRIPTION

[0054] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0055] like Figure 1 As shown, Figure 1 It is a flow chart of the contact stiffness curve acquisition method in the first embodiment, which is applied to a data processing system including at least three shims, a lifting assembly and a supported object. Among them, at least three shims are distributed below the supported object to support the supported object. Since three points can determine a surface, three shims can support the supported object stably enough, while one or two shims cannot support the supported object stably enough, so at least three shims are selected in this embodiment. The lifting assembly is used to give the supported object a controllable lifting force. It can be understood that when the lifting force of the lifting assembly on the supported object is set to 0, the positive pressure transmitted to the at least three shims by the supported object is the largest; and as the lifting force of the lifting assembly on the supported object increases, the positive pressure transmitted to the at least three shims by the supported object decreases accordingly.

[0056] It's worth noting that the supported object in this embodiment can be customized, such as a marble machine tool, an aluminum machine tool, a cast iron machine tool, or other flat materials, without specific limitations. However, the resulting contact stiffness curve is specific to the selected supported object. For example, if the selected supported object is a marble machine tool, the resulting contact stiffness curve only applies to the contact between the pad and the marble machine tool, and not to aluminum, iron, or other supported objects.

[0057] The steps provided by the contact stiffness curve acquisition method in this embodiment include:

[0058] Step S1: Acquire first modal data corresponding to a plurality of preset pressures.

[0059] The first modal data corresponding to the target preset pressure is modal data obtained by performing a modal test on the supported object when the shim is in the target support position and subjected to the target preset pressure. The target preset pressure can be any one of multiple preset pressures, and the preset pressure is the positive pressure exerted by the supported object on the shim.

[0060] For example, if a supported object weighs 900kg and there are three shims, then we can preset the preset pressures that need to be measured to include: 30kg, 60kg, 90kg, 120kg, 150kg, 180kg, 210kg, 240kg, 270kg and 300kg. Then, by setting a suitable lifting force, the target preset pressure can be made to belong to one of the preset pressures. For example, if the lifting force is set to 0, the target preset pressure will be 300kg. Optionally, the above parameters can also be other values, which are not specifically limited here, but in order to increase the preset pressure range, a heavy supported object should be selected as much as possible during actual testing. And in order to improve the accuracy of the measurement results, the preset pressure can also be set as much as possible.

[0061] In a specific embodiment, the first modal data corresponding to the plurality of preset pressures are obtained in the following manner:

[0062] Step S1a: placing shims at target support positions so that the pressure on each shim is less than or equal to a preset difference, and adjusting the target preset pressure.

[0063] Step S1b, controlling the vibration component to transmit vibration to the supported object at one or more vibration positions, obtaining modal data of the supported object at one or more vibration positions as first modal data corresponding to the target preset pressure, so as to obtain first modal data corresponding to multiple preset pressures respectively.

[0064] like Figure 5 As shown, Figure 5This is the first schematic diagram of the data processing system. The lifting force of the lifting component is set to 0, so the lifting component is hidden. The data processing system includes a vibration component 1, a data acquisition component 2, an object 3, a pad 4 and a data processing terminal 5. Among them, the vibration component 1 here uses a hammer. Of course, other objects that can emit vibrations can also be used as the vibration component 1. The data acquisition component 2 uses an acceleration sensor and a data collector. The acceleration sensor is directly set on the object 3. Of course, other devices that can collect the vibration conditions of the object can also be used as the data acquisition component 2. The data processing terminal 5 organizes and analyzes the collected data. In this embodiment, the method of conducting an actual modal test is:

[0065] Alternatively, the position of the data acquisition component 2 is fixed, and the position of the vibration component 1 is continuously moved and vibrated. When the vibration component 1 transmits vibrations to the object 3 at different vibration positions, the data acquisition component 2 is driven to collect actual modal data of the supported object 3 at one or more vibration positions under the target preset pressure.

[0066] Alternatively, the position of vibration assembly 1 is fixed and vibrated, while the position of data acquisition assembly 2 (only the accelerometer) is continuously moved. While vibration assembly 1 transmits vibration to object 3 at the same vibration position, actual modal data of supported object 3 under the target preset pressure is acquired by data acquisition assembly 2 at all set positions.

[0067] like Figure 6 The figure shows the actual modal data obtained. The figure shows many peaks, and generally, each peak corresponds to a certain natural frequency. Each natural frequency also corresponds to a vibration mode, which is how the object vibrates when excited by that frequency. Observing the vibration mode helps us identify and distinguish between different modes. By moving the position of the vibration component or the data acquisition component, we can fully capture the vibration of the bed in all directions, making the vibration mode easy to observe.

[0068] In this embodiment, in order to reduce the variables of each test, it is best to adjust the external force on each shim to be the same. In order to find such a target support position, in a specific embodiment, before executing step S1, as shown in FIG. Figure 2 As shown, the following method is also used:

[0069] Step A1: construct a simulated fixed joint in the simulation system.

[0070] At the same time, a model of the shim must be created within the simulation system to serve as the simulated shim. A model of the supported object must also be created to serve as the simulated supported object. Of course, parameters such as material properties, normal pressure, and number of models must also be entered into the simulation system, and these must all be consistent with the actual physical model.

[0071] Step A2: Connect the simulated shim to the simulated supported object at the supporting position using the simulated fixed hinge, and obtain the bearing pressure output by the simulated fixed hinge.

[0072] Among them, the positions and quantities of the simulated fixed hinges and the simulated pads correspond one to one.

[0073] Step A3: Determine whether the difference in bearing force output by any two of the multiple simulated fixed hinges is less than or equal to a preset difference. If the difference in bearing force is greater than the preset difference, the process proceeds to step A4. If the difference in bearing force output by any two simulated fixed hinges is less than or equal to the preset difference, the process proceeds to step A5.

[0074] Step A4: adjust the support position of each simulation shim and jump to step A2.

[0075] Step A5: setting the adjusted support position of each simulation shim as the target support position.

[0076] The above steps A3-A5 are to continuously confirm whether the current support position of the simulated shim is appropriate based on the bearing force difference between the bearing forces output by different simulated fixed hinges. If the bearing force difference is large, the current support position is adjusted and the judgment steps A2-A4 are repeated. If the bearing force difference is small, the adjusted support position of each simulated shim is directly set as the target support position. The target support position becomes the relative setting position between the supported object and the shim, and the relative setting position between the virtual object and the simulated shim, effectively reducing the variables of each test.

[0077] For example, the number of shims is set to 3. Taking a bed as an example, after multiple adjustments, it is found that when the shims are arranged in Figure 3 When the position is shown, the three pads can evenly share the weight of the bed. The weight load of the bed on the three pads in this position is as follows: Figure 4 As shown, the bearing capacity difference is already very small (that is, the cumulative difference between every two lines on the Y axis in the figure is very small). Of course, in theory, other numbers of shims can be used for testing, but in practice, if four or more shims are used as supports, it is difficult to ensure that each shim is subjected to the same preset pressure. This will increase the test variables and is not conducive to rapid and accurate subsequent simulation approximation. Therefore, when the number of shims is 3, it is the best embodiment of the present invention.

[0078] Of course, in order to determine the support position of the shim, in addition to the load output function of the dynamic simulation system mentioned above, other mechanical analysis methods can also be used.

[0079] Step S2: performing modal simulation to obtain contact stiffness corresponding to a plurality of preset pressures.

[0080] Among them, the contact stiffness corresponding to the target preset pressure is: a simulated washer corresponding to the washer and a simulated supported object corresponding to the supported object are constructed through a simulation system. When the simulated washer is located at a position corresponding to the target support position and the pressure exerted on the simulated washer is the target preset pressure, a modal analysis is performed on the simulated supported object to obtain second modal data. By adjusting the second modal data until the error between the second modal data and the first modal data is less than the preset value, the contact stiffness between the simulated washer and the simulated supported object is obtained.

[0081] Modal simulation involves building a model of an object within a simulation system. After adding parameters such as contact stiffness, material properties, target preset pressure, boundary conditions, and analysis type, a simulated modal test is performed to obtain the second modal data. Since parameters such as material properties, target preset pressure, boundary conditions, and analysis type are known, their addition must be consistent with the actual parameters. However, the contact stiffness is unknown, so the only variable is the contact stiffness. The contact stiffness between the simulated shim and the virtual object is adjusted, and the obtained second modal data is made to approximate the first modal data. This allows the adjusted contact stiffness to continuously approach the actual contact stiffness at the target preset pressure. Finally, when the termination condition is met (i.e., when the error between the second modal data and the first modal data is less than the preset value), the currently adjusted contact stiffness is used as the contact stiffness at the target preset pressure, resulting in the contact stiffness closest to the actual value.

[0082] In a specific embodiment, the contact stiffnesses corresponding to the plurality of preset pressures are obtained in the following manner:

[0083] Step S21, under the condition that the pressure of the simulated support object applied to the simulated shim is set to the target preset pressure, the contact stiffness between the simulated shim and the simulated support object is dynamically adjusted by approximating the second modal data to the first modal data, and modal simulation of the simulated support object is performed.

[0084] Optional, such as Figure 7 As shown in the figure, the following strategies can be used to adjust the contact stiffness between the simulated pad and the simulated supported object:

[0085] Step S21A: determining the target dimension based on the second modal data corresponding to the target preset pressure.

[0086] Specifically, the modal data includes vibration modes in a preset three-dimensional coordinate system. The preset three-dimensional coordinate system includes three dimensions, the target dimension is one of the three dimensions, and the difference between the amplitude of the target dimension and the amplitude of the other two dimensions is greater than the preset amplitude. For example, in the first-order vibration mode, the amplitude in the X direction is A1, the amplitude in the Y direction is A2, the amplitude in the Z direction is A3, and the preset amplitude is A0. If A1-A2>A0 and A1-A3>A0 are satisfied at the same time, then the target dimension of the first-order vibration mode is considered to be the X direction.

[0087] Step S21B: dynamically adjust the contact stiffness between the simulated pad and the simulated supported object in the target dimension, and perform modal simulation so that the vibration mode of the second modal data in the target dimension approaches the vibration mode of the first modal data in the target dimension.

[0088] In other words, select the mode whose vibration shape is mainly reflected in the X direction to adjust the contact stiffness in the X direction; select the mode whose vibration shape is mainly reflected in the Y direction to adjust the contact stiffness in the Y direction; select the mode whose vibration shape is mainly reflected in the Z direction to adjust the contact stiffness in the Z direction.

[0089] For example, Figure 8 As shown, Figure 8 To simulate the changes between the shim and the supported object under the third-order constraint mode, the object moves along the Z direction under the third-order constraint mode, that is, the target dimension vibration mode in the Z direction. At this time, the contact stiffness in the Z direction can be adjusted based on the third-order constraint mode.

[0090] Optional, such as Figure 9 As shown, the following strategies can also be used to adjust the contact stiffness between the simulated pad and the simulated supported object:

[0091] Step S21a, dynamically adjust the contact stiffness between the simulated pad and the simulated supported object, and perform rigid body modal simulation on the supported object so that the preset low-order second modal data obtained by the simulation approaches the preset low-order first modal data under the target preset pressure.

[0092] Specifically, modal simulation includes rigid body modal simulation and flexible body modal simulation. When an object's vibration is restricted, such as when it is fixed in place or in contact with another object, rigid body modal simulation should be performed. Therefore, it is not difficult to understand that the modal simulation performed on the object placed on the pad in this embodiment is a rigid body modal simulation. When performing rigid body modal simulation, the first six orders are all rigid body modes, and only higher orders are flexible body modes.

[0093] Therefore, in this step, the preset low order is set to the first 6 orders. Under the premise of rigid body mode, the contact stiffness between the simulated shim and the simulated supported object is adjusted so that the obtained 6th-order second modal data approximates the 6th-order first modal data. A characteristic of rigid body mode is that the object does not deform, and the vibration mode is completely reflected in a certain direction. Based on this characteristic, the contact stiffness can be roughly adjusted quickly.

[0094] Step S21b: When the difference between the preset low-order first modal data obtained by simulation and the preset low-order second modal data at the target preset pressure is less than the preset value, the contact stiffness between the simulated pad and the simulated supported object is dynamically adjusted, and the supported object is subjected to flexible body modal simulation, so that the preset high-order second modal data obtained by simulation approaches the preset high-order first modal data at the target preset pressure.

[0095] In this step, the preset high order is set to 7 or higher. Based on the flexible body mode, the contact stiffness between the simulated shim and the simulated supported object is adjusted so that the acquired second modal data of 7 or higher approximates the first modal data of 7 or higher. The vibration shapes corresponding to the flexible body mode are more complex, and combining these complex vibration shapes allows for fine-tuning of the contact stiffness. This means fine-tuning the contact stiffness until the error between the second modal data and the first modal data is reduced to a certain level.

[0096] In step S22 , the contact stiffness obtained when the error between the second modal data and the first modal data is less than a preset value is used as the contact stiffness corresponding to the target preset pressure, so as to obtain contact stiffnesses corresponding to multiple preset pressures respectively.

[0097] Step S3: fitting the contact stiffness corresponding to a plurality of preset pressures to obtain a contact stiffness curve.

[0098] After completing the test for all preset pressures, data fitting is performed. This can be done using least squares curve fitting or other existing fitting methods, which are not specifically limited here. After fitting, a contact stiffness curve is obtained, including curves of contact stiffness in the X, Y, and Z directions at different preset pressures.

[0099] The above-mentioned contact stiffness curve acquisition method first obtains first modal data corresponding to multiple preset pressures; then performs modal simulation to obtain the contact stiffness corresponding to each of the multiple preset pressures; and finally, fits the contact stiffness corresponding to each of the multiple preset pressures to obtain a contact stiffness curve. The present invention provides a method for rapidly acquiring the contact stiffness curve between a supported object and a shim under different preset pressures. By combining simulation and testing, the dynamic characteristics of the interface between the object and the shim can be quickly and accurately determined.

[0100] like Figure 10 As shown, Figure 10 FIG. 5 is a flow chart of a method for obtaining a contact stiffness curve in a second embodiment. The second embodiment can also verify the accuracy of the contact stiffness curve. The specific steps include:

[0101] Step S1: Acquire first modal data corresponding to a plurality of preset pressures.

[0102] Step S2: performing modal simulation to obtain contact stiffness corresponding to a plurality of preset pressures.

[0103] Step S3: fitting the contact stiffness corresponding to a plurality of preset pressures to obtain a contact stiffness curve.

[0104] Steps S1 to S3 of the contact stiffness curve acquisition method in the second embodiment are consistent with steps S1 to S3 of the contact stiffness curve acquisition method in the first embodiment, and are not described in detail here.

[0105] Step S4: adjusting the pressure transmitted by the supported object to the shim to the test pressure, performing a modal test on the supported object, and obtaining third modal data of the supported object under the test pressure.

[0106] The test pressure is different from all preset pressures. For example, if the preset pressures include 30kg, 60kg, 90kg, 120kg, 150kg, 180kg, 210kg, 240kg, 270kg and 300kg, the test pressure can be set to 100kg to achieve the purpose of the test.

[0107] The modal test is the same as step S1 of the contact stiffness curve acquisition method in the first embodiment. Based on the above step S4, the third modal data of the supported object under the test pressure can be acquired.

[0108] Step S5, matching the equivalent contact stiffness corresponding to the test pressure from the contact stiffness curve, setting the contact stiffness to the equivalent contact stiffness under modal simulation in the simulation system, and obtaining the fourth modal data of the supported object under the test pressure.

[0109] That is, no adjustment is required. Simply substitute the test pressure into the contact stiffness curve to obtain the equivalent contact stiffness. This is a theoretical value. If the contact stiffness curve is accurate, the equivalent contact stiffness is close enough to the actual value.

[0110] The modal simulation will not be described in detail. Based on the above step S5, the fourth modal data of the simulated supported object under the test pressure can be obtained.

[0111] Step S6, determining whether the error between the third modal data and the fourth modal data is less than a preset value. If the error between the third modal data and the fourth modal data is less than the preset value, jump to step S7; if the error between the third modal data and the fourth modal data is greater than or equal to the preset value, jump to step S1.

[0112] Step S7: determining whether the contact stiffness curve is accurate.

[0113] Of course, the above example only uses one test pressure. Multiple test pressures can also be set. If all multiple test pressures meet the judgment conditions of step S6, the contact stiffness curve can also be determined to be accurate. If any one of them does not meet the judgment conditions, the process can jump to step S1 to re-obtain the contact stiffness curve.

[0114] In one embodiment, Figure 11 As shown, a contact stiffness curve acquisition device is proposed, which includes:

[0115] The real modal test module 1102 is used to obtain first modal data corresponding to multiple preset pressures, wherein the first modal data corresponding to the target preset pressure is the modal data obtained by performing a modal test on the supported object when the shim is in the target support position and the pressure it is subjected to is the target preset pressure; the target preset pressure is any one of the multiple preset pressures, and the preset pressure is the positive pressure exerted by the supported object on the shim;

[0116] The modal simulation module 1104 is configured to perform a modal simulation to obtain contact stiffnesses corresponding to the plurality of preset pressures, wherein the contact stiffness corresponding to the target preset pressure is as follows: a simulated shim corresponding to the shim and a simulated supported object corresponding to the supported object are constructed by a simulation system; when the simulated shim is located at a position corresponding to the target support position and the pressure applied to the simulated shim is the target preset pressure, a modal analysis is performed on the simulated supported object to obtain second modal data; and the contact stiffness between the simulated shim and the simulated supported object is obtained by adjusting the second modal data until the error between the second modal data and the first modal data is less than a preset value.

[0117] The fitting module 1108 is configured to fit the contact stiffnesses corresponding to the plurality of preset pressures to obtain a contact stiffness curve.

[0118] Figure 12 FIG. 1 shows an internal structure diagram of a contact stiffness curve acquisition device in one embodiment. Figure 12As shown, the contact stiffness curve acquisition device includes a processor, a memory, and a network interface connected via a system bus. The memory includes a non-volatile storage medium and an internal memory. The non-volatile storage medium of the contact stiffness curve acquisition device stores an operating system and may also store a computer program. When the computer program is executed by the processor, the processor can implement the contact stiffness curve acquisition method. The internal memory may also store a computer program. When the computer program is executed by the processor, the processor can implement the contact stiffness curve acquisition method. Those skilled in the art will understand that Figure 12 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the contact stiffness curve acquisition device to which the solution of the present application is applied. The specific contact stiffness curve acquisition device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0119] A contact stiffness curve acquisition device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following steps are implemented: Step S1, obtaining first modal data corresponding to multiple preset pressures; Step S2, performing modal simulation to obtain contact stiffness corresponding to the multiple preset pressures; Step S3, fitting the contact stiffness corresponding to the multiple preset pressures to obtain a contact stiffness curve.

[0120] A computer-readable storage medium stores a computer program, which implements the following steps when executed by a processor: Step S1, obtaining first modal data corresponding to multiple preset pressures; Step S2, performing modal simulation to obtain contact stiffness corresponding to the multiple preset pressures; Step S3, fitting the contact stiffness corresponding to the multiple preset pressures to obtain a contact stiffness curve.

[0121] It should be noted that the above-mentioned contact stiffness curve acquisition method, device, equipment and computer-readable storage medium belong to a general inventive concept, and the contents of the embodiments of the contact stiffness curve acquisition method, device, equipment and computer-readable storage medium are applicable to each other.

[0122] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, which can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0123] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for obtaining a contact stiffness curve for the interface between a supported object and a pad, characterized in that: The method comprises: Step S1, obtaining first modal data corresponding to a plurality of preset pressures, wherein the first modal data corresponding to the target preset pressure is modal data obtained by performing a modal test on the supported object when the shim is in a target support position and the pressure applied thereto is the target preset pressure; the target preset pressure is any one of the plurality of preset pressures, and the preset pressure is the positive pressure exerted by the supported object on the shim; Step S2, performing modal simulation to obtain contact stiffnesses corresponding to the multiple preset pressures, wherein the contact stiffness corresponding to the target preset pressure is: constructing a simulated shim corresponding to the shim and a simulated supported object corresponding to the supported object through a simulation system; when the simulated shim is located at a position corresponding to the target support position and the pressure exerted on the simulated shim is the target preset pressure, performing modal analysis on the simulated supported object to obtain second modal data; by adjusting the second modal data until the error between the second modal data and the first modal data is less than a preset value, obtaining the contact stiffness between the simulated shim and the simulated supported object; Step S3, fitting the contact stiffnesses corresponding to the plurality of preset pressures to obtain a contact stiffness curve; The number of the simulation shims is at least 3, and before step S1, the following steps are further included: Step A1, constructing a simulated fixed hinge in the simulation system; Step A2: connecting the simulated shim to the simulated supported object at the supporting position using the simulated fixed hinge, and obtaining the bearing force output by the simulated fixed hinge, wherein the positions and quantities of the simulated fixed hinge and the simulated shims correspond one to one; Step A3: Determine whether the difference in the bearing pressure output by any two of the multiple simulated fixed hinges is less than or equal to a preset difference. If the difference in the bearing pressure is greater than the preset difference, jump to step A4. If the difference in the bearing pressure output by any two simulated fixed hinges is less than or equal to the preset difference, jump to step A5. Step A4, adjusting the support position of each simulation shim and jumping to step A2; Step A5: setting the adjusted support position of each simulation shim as the target support position.

2. The method for obtaining a contact stiffness curve according to claim 1, wherein: Step S2 includes: Step S21, under the condition that the pressure exerted on the simulated support by the simulated shim is set to a target preset pressure, dynamically adjusting the contact stiffness between the simulated shim and the simulated support by approximating the second modal data to the first modal data, and performing modal simulation on the simulated support; In step S22 , the contact stiffness obtained when the error between the second modal data and the first modal data is less than a preset value is used as the contact stiffness corresponding to the target preset pressure, so as to obtain the contact stiffnesses corresponding to the multiple preset pressures respectively.

3. The method according to claim 2, characterized in that The modal data includes vibration modes in a preset three-dimensional coordinate system. Step S21 includes: Step S21A: determining a target dimension based on the second modal data corresponding to the target preset pressure; wherein the preset three-dimensional coordinate system includes three dimensions, the target dimension is one of the three dimensions, and the difference between the amplitude of the target dimension and the amplitudes of the other two dimensions is greater than a preset amplitude; Step S21B, dynamically adjust the contact stiffness between the simulated pad and the simulated supported object in the target dimension, and perform modal simulation so that the vibration mode of the second modal data in the target dimension approaches the vibration mode of the first modal data in the target dimension.

4. The method according to claim 2, characterized in that The modal simulation includes: rigid body modal simulation and flexible body modal simulation, and step S21 includes: Step S21a, dynamically adjusting the contact stiffness between the simulated shim and the simulated supported object, and performing rigid body modal simulation on the supported object so that the preset low-order second modal data obtained by the simulation approaches the preset low-order first modal data under the target preset pressure; Step S21b, when the difference between the preset low-order first modal data obtained by the simulation and the preset low-order second modal data at the target preset pressure is less than the preset value, dynamically adjust the contact stiffness between the simulated pad and the simulated supported object, and perform flexible body modal simulation on the supported object, so that the preset high-order second modal data obtained by the simulation approaches the preset high-order first modal data at the target preset pressure.

5. The method according to claim 1, wherein Step S1 includes: Step S1a, placing the shims at the target support positions so that the pressure on each shim is less than or equal to a preset difference, and adjusting the target preset pressure; Step S1b: Control the vibration component to transmit vibration to the supported object at one or more vibration positions, obtain modal data of the supported object at the one or more vibration positions as the first modal data corresponding to the target preset pressure, so as to obtain the first modal data corresponding to the multiple preset pressures respectively.

6. The method according to claim 1, characterized in that After step S3, the following steps are also included: Step S4, adjusting the pressure transmitted by the supported object to the shim to a test pressure, and performing a modal test on the supported object to obtain third modal data of the supported object under the test pressure; Step S5, matching an equivalent contact stiffness corresponding to the test pressure from the contact stiffness curve, setting the contact stiffness to the equivalent contact stiffness under modal simulation in a simulation system, and obtaining fourth modal data of the supported object under the test pressure; Step S6, determining whether an error between the third modal data and the fourth modal data is less than a preset value; if the error between the third modal data and the fourth modal data is less than the preset value, jumping to step S7; if the error between the third modal data and the fourth modal data is greater than or equal to the preset value, jumping to step S1; Step S7: determining whether the contact stiffness curve is accurate.

7. A contact stiffness curve acquisition device, using the contact stiffness curve acquisition method according to claim 1, characterized in that: The device comprises: A real modal test module is used to obtain first modal data corresponding to multiple preset pressures, wherein the first modal data corresponding to the target preset pressure is the modal data obtained by performing a modal test on the supported object when the shim is in the target support position and the pressure it is subjected to is the target preset pressure; the target preset pressure is any one of the multiple preset pressures, and the preset pressure is the positive pressure generated by the supported object on the shim; a modal simulation module for performing modal simulation to obtain contact stiffnesses corresponding to the multiple preset pressures, wherein the contact stiffness corresponding to the target preset pressure is: constructing a simulated shim corresponding to the shim and a simulated supported object corresponding to the supported object through a simulation system; when the simulated shim is located at a position corresponding to the target support position and the pressure applied to the simulated shim is the target preset pressure, performing modal analysis on the simulated supported object to obtain second modal data; and obtaining the contact stiffness between the simulated shim and the simulated supported object by adjusting the second modal data until the error between the second modal data and the first modal data is less than a preset value; The fitting module is used to fit the contact stiffnesses corresponding to the plurality of preset pressures to obtain a contact stiffness curve.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 6.

9. A contact stiffness curve acquisition device, comprising a memory and a processor, characterized in that: The memory stores a computer program, and when the computer program is executed by the processor, the processor is caused to perform the steps of the method according to any one of claims 1 to 6.

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