Method for measuring and simulating six-degree-of-freedom nonlinear rigidity and damping of shock absorber

Abstract

The invention provides a method for measuring and simulating six-degree-of-freedom non-linear rigidity and damping of a shock absorber, and relates to the technical field of photoelectric pod shock absorbers. According to the measuring method, loads and displacement curves of the shock absorber in three translation directions and torques and angular displacement curves of the shock absorber in three rotation directions are measured through a test bed; the method comprises the following steps: calibrating non-linear translational stiffness and non-linear torsional stiffness, and measuring frequency response curves of the shock absorber in three translational directions and frequency response curves of the shock absorber in three rotating directions by adopting a force hammer excitation mode to obtain damping ratio parameters in the translational directions and the torsional directions; according to the simulation method, the six-degree-of-freedom nonlinear rigidity and damping data of the shock absorber are applied to finite element calculation, and the influence of the shock absorber on the shock absorption effect of a product is analyzed; the problems that according to an existing simulation method, a nonlinear material is difficult to accurately simulate, the nonlinear rigidity and damping characteristics of the shock absorber in six directions cannot be completely simulated, and the shock absorber effect is difficult to predict in the state that a prototype does not exist are solved.

Description

Technical Field

[0001] The invention relates to the technical field of photoelectric pod shock absorbers, and in particular to a six-degree-of-freedom nonlinear stiffness and damping measurement and simulation method for a shock absorber. Background Art

[0002] In order to reduce the impact of external vibration on optoelectronic pod products, a shock absorber structure is generally placed in the pod. The stiffness-damping characteristics of the shock absorber directly affect the natural frequency of the pod system and the response to external vibration excitation, thereby affecting the function of the product. There are currently two main methods to evaluate the stiffness and damping characteristics of the shock absorber: one is the experimental method, in which the shock absorber is placed on the pod for a vibration test, and the natural frequency and vibration response amplitude of the whole machine are judged by collecting the response data of the sensor. This method requires the physical prototype of the whole pod product as a prerequisite, which cannot be achieved without a prototype, resulting in the inability to evaluate the stiffness and damping characteristics of the shock absorber. Prediction is carried out in the early stage of product development; the other is simulation technology, which simulates the shock absorber based on the finite element simulation method. There is no need for a physical prototype of the pod. This simulation method has a short cycle and low cost, but the difficulty lies in that the vibration damping elements of the shock absorber are generally rubber, metal rubber, wire rope, etc., which have nonlinear material characteristics and are difficult to simulate accurately; and the general simulation method only simulates the stiffness of the shock absorber in a single direction or three translational directions, and it is difficult to fully simulate the nonlinear stiffness and damping characteristics of the shock absorber in six directions. Therefore, a method for simulating the nonlinear stiffness and damping characteristics of the six degrees of freedom of the shock absorber with higher precision is needed. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects in the prior art, thereby providing a method for measuring and simulating the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber.

[0004] A method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, the method comprising the following steps: Step XS1, performing tension and compression tests on the shock absorber in the translation direction along the x-axis direction, y-axis direction and z-axis direction of the coordinate system, respectively, obtaining force and displacement curves of the shock absorber in the x-axis direction, y-axis direction and z-axis direction of the coordinate system, and obtaining translation stiffness parameters of the shock absorber in the x-axis direction, y-axis direction and z-axis direction of the coordinate system according to the force and displacement curves; Step XS2, performing positive and negative torsion tests on the shock absorber in the rotation direction around the x-axis, y-axis and z-axis of the coordinate system respectively, obtaining torque and angular displacement curves of the shock absorber rotating around the x-axis, y-axis and z-axis of the coordinate system respectively, and obtaining torsional stiffness parameters of the shock absorber rotating around the x-axis, y-axis and z-axis of the coordinate system respectively according to the torque and angular displacement curves; Step XS3, installing the shock absorber on the test bench base, installing a counterweight on the shock absorber, placing an acceleration sensor on the counterweight, using a hammer to excite the counterweight along the x-axis direction, y-axis direction and z-axis direction of the coordinate system, and correspondingly obtaining the acceleration response curves of the counterweight in the x-axis direction, y-axis direction and z-axis direction of the coordinate system; Step XS4, install one end of the shock absorber on the upper stand, the other end of the shock absorber on the counterweight turntable, the counterweight turntable on the rotating shaft, install a gyroscope on the end of the shock absorber close to the counterweight turntable, use a force hammer to excite the force hammer striking point along the tangent direction of the counterweight turntable, and obtain the angular acceleration response curve of the counterweight turntable along the z-axis direction of the coordinate system; Step XS5, placing the shock absorber horizontally, mounting one end of the shock absorber on the first adapter bracket, mounting the other end of the shock absorber on the second adapter bracket, mounting the second adapter bracket on the counterweight turntable, mounting a gyroscope on the counterweight turntable, mounting the counterweight turntable on the rotating shaft, using a force hammer to excite the force hammer striking point along the tangent direction of the counterweight turntable, and obtaining an angular acceleration response curve of the counterweight turntable along the x-axis direction of the coordinate system; Step XS6, based on step XS5, the shock absorber is rotated 90° clockwise along the horizontal axis, and a hammer is used to excite the hammer striking point along the tangent direction of the counterweight turntable to obtain an angular acceleration response curve of the counterweight turntable along the y-axis direction of the coordinate system; Step XS7, according to the acceleration response curves of the counterweight block in the x-axis direction, y-axis direction and z-axis direction of the coordinate system in step XS3, the angular acceleration response curve of the counterweight turntable along the z-axis direction of the coordinate system in step XS4, the angular acceleration response curve of the counterweight turntable along the x-axis direction of the coordinate system in step XS5, and the angular acceleration response curve of the counterweight turntable along the y-axis direction of the coordinate system in step XS6, obtain the vibration response value of the first point x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2; Step XS8, based on the vibration response value of the first point in step XS7 x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2 Obtain the six-degree-of-freedom damping parameters of the shock absorber.

[0005] Furthermore, in step XS1, the translational stiffness parameters of the shock absorber in the x-axis direction, y-axis direction and z-axis direction of the coordinate system are obtained by performing discrete point fitting on the force and displacement curves of the shock absorber in the x-axis direction, y-axis direction and z-axis direction of the coordinate system.

[0006] Furthermore, in step XS2, the torsional stiffness parameters of the shock absorber rotating around the x-axis, y-axis and z-axis of the coordinate system are obtained by performing discrete point fitting on the torque and angular displacement curves of the shock absorber rotating around the x-axis, y-axis and z-axis of the coordinate system.

[0007] Further, in step XS8, the vibration response value of the first point in step XS7 is x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2. Obtain the equivalent viscous damping ratio of the shock absorber, and obtain the six-degree-of-freedom damping parameters of the shock absorber according to the equivalent viscous damping ratio.

[0008] Furthermore, the gyroscope is located on the rotation axis of the counterweight turntable.

[0009] Furthermore, the first adapter bracket is installed on the upper stand.

[0010] Furthermore, the rotation axis of the counterweight turntable coincides with the geometric center of the shock absorber.

[0011] Furthermore, the rotating shaft is installed on a test bench base.

[0012] The present invention also includes a method for simulating the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, the method including all the steps in any one of the above-mentioned methods for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, and the simulation method also includes the following steps: Step XS9, establishing a finite element simulation model of the optoelectronic pod product; Step XS10, performing finite element modeling on the mounting and fixing ends of the shock absorber, establishing a stiffness and damping connection unit between the mounting and fixing ends of the shock absorber, and connecting the stiffness and damping connection unit to the mounting and fixing ends of the shock absorber; Step XS11, assign the translational stiffness parameters of the shock absorber in the x-axis direction, y-axis direction and z-axis direction of the coordinate system, the torsional stiffness parameters of the shock absorber rotating around the x-axis, y-axis and z-axis of the coordinate system, and the six-degree-of-freedom damping parameters of the shock absorber to the stiffness damping connection unit, and perform finite element simulation calculations.

[0013] Furthermore, the establishment of a finite element simulation model of the optoelectronic pod product includes finite element meshing, connection relationship processing between components and material property assignment.

[0014] The technical solution of the present invention has the following advantages: The technical solution of the present invention is to measure the load and displacement curves of the shock absorber in three translational directions through a test bench to calibrate its nonlinear translational stiffness, measure the torque and angular displacement curves of the shock absorber in three rotational directions through the test bench to calibrate its nonlinear torsional stiffness, and adopt a force hammer excitation method to measure the frequency response curves of the shock absorber in three translational directions to calibrate its damping ratio parameters; at the same time, the frequency response curves of the shock absorber in three rotational directions are measured by using a force hammer to excite a counterweight turntable to calibrate the damping ratio parameters in the torsional direction; the six-degree-of-freedom nonlinear stiffness and damping data of the shock absorber are applied to finite element calculations to analyze the influence of the shock absorber on the vibration reduction effect of the product, and the measurement and simulation methods proposed in the present application solve the problem of predicting the effect of the shock absorber in the absence of a prototype, thereby shortening the research and development cycle and saving costs, and effectively improving the accuracy and efficiency of the shock absorber performance test, providing important support for the development of related products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 The force and displacement curves of the shock absorber of the present invention obtained after the tension and compression tests in the translation direction along the x-axis direction, the y-axis direction and the z-axis direction of the coordinate system; Figure 2 The torque and angular displacement curves obtained after the shock absorber of the present invention is subjected to positive and negative torsion tests in the rotation direction around the x-axis, y-axis and z-axis of the coordinate system; Figure 3 For the present invention Figure 1 The force and displacement curve in the figure is fitted with discrete points; Figure 4 For the present invention Figure 2 The torque and angular displacement curve in the figure is fitted with discrete points; Figure 5 It is a schematic diagram of the connection between the acceleration sensor, the counterweight, the shock absorber and the test bench base of the present invention; Figure 6 It is a schematic diagram of the connection between the gyroscope, the counterweight turntable and the rotating shaft of the present invention; Figure 7 It is a schematic diagram of the connection of the upper stand, the first adapter bracket, the second adapter bracket, the shock absorber, the gyroscope and the counterweight turntable of the present invention; Figure 8It is a schematic diagram of the connection between the shock absorber, the first adapter bracket, the second adapter bracket, the gyroscope, the counterweight turntable and the rotating shaft of the present invention; Fig. 9 It is a time domain acceleration and angular acceleration response curve diagram measured by the acceleration sensor and gyroscope of the present invention; Fig.10 It is a schematic diagram of a finite element simulation model in which the vibration absorber of the present invention is installed on an optoelectronic pod; Fig.11 A schematic diagram of a finite element simulation model for establishing a stiffness damping connection unit for the mounting fixed end of the shock absorber of the present invention.

[0017] Description of reference numerals: 1-acceleration sensor; 2-counterweight block; 3-shock absorber; 4-test bench base; 5-gyroscope; 6-counterweight turntable; 7-rotating shaft; 8-hammer striking point; 9-first adapter bracket; 10-stiffness damping connection unit; 11-upper stand; 12-second adapter bracket. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be described clearly and completely below 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] like Figure 1 to Figure 9 A method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber is shown, and the measuring method comprises the following steps: Step XS1: On a tension and compression testing machine, perform tension and compression tests on the shock absorber 3 in the translation direction along the x-axis direction, y-axis direction and z-axis direction of the coordinate system, and obtain the corresponding Figure 1 The force and displacement curves of the shock absorber 3 in the x-axis direction, y-axis direction and z-axis direction of the coordinate system are shown, where the negative direction represents that the shock absorber 3 is compressed. The force and displacement curves of the shock absorber 3 in the x-axis direction, y-axis direction and z-axis direction of the coordinate system are fitted with discrete points to obtain Figure 3 The fitted curve diagram is shown in Table 1, thereby obtaining the discrete point data table of the translational stiffness parameters of the shock absorber 3 in the x-axis direction, y-axis direction and z-axis direction of the coordinate system; Table 1 Discrete point data table of translational stiffness parameters

[0023] Step XS2: On a torsion testing machine, perform positive and negative torsion tests on the shock absorber 3 in the rotation direction around the x-axis, y-axis and z-axis of the coordinate system, and obtain the corresponding Figure 2 The torque and angular displacement curves of the shock absorber 3 rotating around the x-axis, y-axis and z-axis of the coordinate system are shown, wherein the negative direction represents that the shock absorber 3 is subjected to counterclockwise torque. The torque and angular displacement curves of the shock absorber 3 rotating around the x-axis, y-axis and z-axis of the coordinate system are fitted with discrete points to obtain Figure 4 The curve diagram after fitting is shown in Table 2, thereby obtaining the discrete point data table of torsional stiffness parameters of the shock absorber 3 rotating around the x-axis, y-axis and z-axis of the coordinate system; Table 2 Torsional stiffness parameter discrete point data table

[0024] The discrete point data table of translation stiffness parameters in Table 1 and the discrete point data table of torsional stiffness parameters in Table 2 are used as the six-degree-of-freedom nonlinear stiffness parameters of the shock absorber 3; Step XS3, as Figure 5 As shown, one end of the shock absorber 3 is mounted on the test bench base 4, a solid steel counterweight block 2 with a mass of m is mounted on the shock absorber 3, an acceleration sensor 1 is arranged on the counterweight block 2, and a hammer is used to stimulate the surface of the counterweight block 2 along the x-axis direction, y-axis direction and z-axis direction of the coordinate system, respectively, to obtain the acceleration response curves of the counterweight block 2 in the x-axis direction, y-axis direction and z-axis direction of the coordinate system; Step XS4, as Figure 6As shown, one end of the shock absorber 3 is mounted on the upper stand 11, and the other end of the shock absorber 3 is mounted on a counterweight turntable 6 with a vertical axis moment of inertia of I, the counterweight turntable 6 is mounted on a rotating shaft 7, and the rotating shaft 7 is mounted on a test bench base 4, and a gyroscope 5 is mounted on one end of the shock absorber 3 close to the counterweight turntable 6, and the gyroscope 5 is located on the rotation axis of the counterweight turntable 6, and the rotation axis of the counterweight turntable 6 is the z-axis direction of the shock absorber 3, and a force hammer is used to excite the force hammer striking point 8 along the tangent direction of the counterweight turntable 6, and the force hammer striking point 8 is located on the counterweight turntable 6, and the angular acceleration response curve of the counterweight turntable 6 along the z-axis direction of the coordinate system is obtained; Step XS5, as Figure 7 As shown, the shock absorber 3 is placed horizontally, one end of the shock absorber 3 is mounted on the first adapter bracket 9, the first adapter bracket 9 is mounted on the upper stand 11, the other end of the shock absorber 3 is mounted on the second adapter bracket 12, the second adapter bracket 12 is mounted on the counterweight turntable 6, the gyroscope 5 is mounted on the counterweight turntable 6, the counterweight turntable 6 is mounted on the rotating shaft 7, the rotating shaft 7 is mounted on the test bench base 4, the rotation axis of the counterweight turntable 6 coincides with the geometric center of the shock absorber 3, the rotation axis of the counterweight turntable 6 is the x-axis direction of the shock absorber 3, a force hammer is used to excite the force hammer to hit the point 8 along the tangent direction of the counterweight turntable 6, and the angular acceleration response curve of the counterweight turntable 6 along the x-axis direction of the coordinate system is obtained; Step XS6, as Figure 8 As shown, on the basis of step XS5, the shock absorber 3 is rotated 90° clockwise along the horizontal axis, one end of the shock absorber 3 is mounted on the second adapter bracket 12, and the other end of the shock absorber 3 is mounted on the first adapter bracket 9, the rotation axis of the counterweight turntable 6 is the y-axis direction of the shock absorber 3, and a force hammer is used to excite the force hammer to hit the point 8 along the tangent direction of the counterweight turntable 6 to obtain the angular acceleration response curve of the counterweight turntable 6 along the y-axis direction of the coordinate system; Step XS7, according to the acceleration response curves of the counterweight block 2 in the x-axis direction, y-axis direction and z-axis direction of the coordinate system in step XS3, the angular acceleration response curve of the counterweight turntable 6 along the z-axis direction of the coordinate system in step XS4, the angular acceleration response curve of the counterweight turntable 6 along the x-axis direction of the coordinate system in step XS5, and the angular acceleration response curve of the counterweight turntable 6 along the y-axis direction of the coordinate system in step XS6, obtain the vibration response value of the first point x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2; Step XS8, based on the vibration response value of the first point in step XS7 x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2, and the theory of free vibration of damped systems, combined with Fig. 9From the time domain acceleration and angular acceleration response curves measured by the acceleration sensor 1 and the gyroscope 5 shown in FIG. 1 , it can be seen that the logarithmic attenuation rate of the vibration system is: ; in, is the logarithmic attenuation rate of the vibration system; is the equivalent viscous damping ratio of the system; is the natural frequency of the system; is the system vibration period; is the vibration response value of the first point, is the vibration response value of the second point which is T away from the first point by the system vibration period; From the calculation formula of the logarithmic decay rate of the vibration system, it can be inferred that if there are i cycles between them, the logarithmic decay rate of the vibration system is: ; The calculation formula of the logarithmic decay rate of the vibration system within one vibration cycle is combined with the calculation formula of the logarithmic decay rate of the vibration system within i cycles, and the equivalent viscous damping ratio of the system is obtained as follows: ; Thus, the six-degree-of-freedom damping parameters of the shock absorber 3 are obtained according to the equivalent viscous damping ratio.

[0025] The above-mentioned shock absorber six-degree-of-freedom nonlinear stiffness and damping measurement method measures the load and displacement curves of the shock absorber 3 in three translational directions through a test bench to calibrate its nonlinear translational stiffness, measures the torque and angular displacement curves of the shock absorber 3 in three rotational directions through a test bench to calibrate its nonlinear torsional stiffness, and adopts a force hammer excitation method to measure the frequency response curves of the shock absorber 3 in three translational directions, and then calibrates its damping ratio parameters; at the same time, the frequency response curves of the shock absorber 3 in three rotational directions are measured by using a force hammer to excite the counterweight turntable 6 to calibrate the damping ratio parameters in the torsional direction; through the measurement method proposed in the present application, the six-degree-of-freedom nonlinear stiffness and damping data of the shock absorber 3 are obtained with high accuracy.

[0026] like Fig.10 and Fig.11 As shown, the present invention also includes a method for simulating the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, which includes all the steps in the above-mentioned method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, and the simulation method also includes the following steps: Step XS9, establish a finite element simulation model of the optoelectronic pod product, such as Fig.10 As shown, it specifically includes finite element mesh division, connection relationship processing between components and material property assignment; Step XS10, finite element modeling is performed on the mounting and fixing end of the shock absorber 3, such as Fig.11 As shown, a stiffness damping connection unit 10 is established between the mounting and fixing ends of the shock absorber 3, and the stiffness damping connection unit 10 is connected to the mounting and fixing ends of the shock absorber 3; Step XS11, assign the translational stiffness parameters of the shock absorber 3 in the x-axis direction, y-axis direction and z-axis direction of the coordinate system, the torsional stiffness parameters of the shock absorber 3 rotating around the x-axis, y-axis and z-axis of the coordinate system, and the six-degree-of-freedom damping parameters of the shock absorber 3 to the stiffness damping connection unit 10 respectively, and perform finite element simulation calculations.

[0027] The above-mentioned shock absorber six-degree-of-freedom nonlinear stiffness and damping simulation method applies the six-degree-of-freedom nonlinear stiffness and damping data of the shock absorber 3 to the finite element calculation, analyzes the influence of the shock absorber 3 on the vibration reduction effect of the product, and solves the problem of predicting the effect of the shock absorber 3 in the absence of a prototype, thereby shortening the research and development cycle and saving costs, and effectively improving the accuracy and efficiency of the performance test of the shock absorber 3, providing important support for the development of related products.

[0028] The six-degree-of-freedom nonlinear stiffness and damping measurement method of the shock absorber provided in the present application is used to obtain the discrete point data table of the translation stiffness parameter in Table 1 and the discrete point data table of the torsional stiffness parameter in Table 2 as the six-degree-of-freedom nonlinear stiffness parameters of the shock absorber 3. If the measurement obtains a period of one direction, , the equivalent viscous damping ratio can be calculated That is, the damping parameters of the shock absorber 3 are obtained, and then according to the six-degree-of-freedom nonlinear stiffness and damping simulation method of the shock absorber provided in the present application, the six-degree-of-freedom nonlinear stiffness parameters and damping parameters of the shock absorber 3 are used in the finite element simulation software to perform simulation analysis of the product, such as static analysis, modal analysis, vibration frequency response analysis and acceleration impact analysis.

[0029] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, characterized in that: The measuring method comprises the following steps: Step XS1, performing tension and compression tests on the shock absorber (3) in the translation direction along the x-axis direction, y-axis direction and z-axis direction of the coordinate system, respectively, obtaining force and displacement curves of the shock absorber (3) in the x-axis direction, y-axis direction and z-axis direction of the coordinate system, and obtaining translation stiffness parameters of the shock absorber (3) in the x-axis direction, y-axis direction and z-axis direction of the coordinate system according to the force and displacement curves; Step XS2, performing positive and negative torsion tests on the shock absorber (3) in the rotation direction around the x-axis, y-axis and z-axis of the coordinate system respectively, obtaining torque and angular displacement curves of the shock absorber (3) rotating around the x-axis, y-axis and z-axis of the coordinate system respectively, and obtaining torsional stiffness parameters of the shock absorber (3) rotating around the x-axis, y-axis and z-axis of the coordinate system respectively according to the torque and angular displacement curves; Step XS3, installing the shock absorber (3) on the test bench base (4), installing a counterweight (2) on the shock absorber (3), placing an acceleration sensor (1) on the counterweight (2), using a hammer to excite the counterweight (2) along the x-axis direction, y-axis direction and z-axis direction of the coordinate system, and obtaining corresponding acceleration response curves of the counterweight (2) in the x-axis direction, y-axis direction and z-axis direction of the coordinate system; Step XS4, mounting one end of the shock absorber (3) on the upper stand (11), mounting the other end of the shock absorber (3) on the counterweight turntable (6), mounting the counterweight turntable (6) on the rotating shaft (7), mounting a gyroscope (5) on one end of the shock absorber (3) close to the counterweight turntable (6), using a force hammer to excite the force hammer striking point (8) along the tangential direction of the counterweight turntable (6), and obtaining an angular acceleration response curve of the counterweight turntable (6) along the z-axis direction of the coordinate system; Step XS5, placing the shock absorber (3) horizontally, mounting one end of the shock absorber (3) on a first adapter bracket (9), mounting the other end of the shock absorber (3) on a second adapter bracket (12), mounting the second adapter bracket (12) on a counterweight turntable (6), mounting a gyroscope (5) on the counterweight turntable (6), mounting the counterweight turntable (6) on a rotating shaft (7), using a force hammer to excite a force hammer striking point (8) along a tangent direction of the counterweight turntable (6), and obtaining an angular acceleration response curve of the counterweight turntable (6) along the x-axis direction of the coordinate system; Step XS6, based on step XS5, the shock absorber (3) is rotated 90° clockwise along the horizontal axis, and a hammer is used to excite the hammer striking point (8) along the tangent direction of the counterweight turntable (6) to obtain an angular acceleration response curve of the counterweight turntable (6) along the y-axis direction of the coordinate system; Step XS7, obtaining the vibration response value of the first point according to the acceleration response curves of the counterweight block (2) in the x-axis direction, the y-axis direction and the z-axis direction of the coordinate system in step XS3, the angular acceleration response curve of the counterweight turntable (6) along the z-axis direction of the coordinate system in step XS4, the angular acceleration response curve of the counterweight turntable (6) along the x-axis direction of the coordinate system in step XS5, and the angular acceleration response curve of the counterweight turntable (6) along the y-axis direction of the coordinate system in step XS6 x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2; Step XS8, based on the vibration response value of the first point in step XS7 x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2 Obtain the six-degree-of-freedom damping parameters of the shock absorber (3).

2. A method for measuring six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: In the step XS1, discrete point fitting is performed on the force and displacement curves of the shock absorber (3) in the x-axis direction, y-axis direction and z-axis direction of the coordinate system to obtain the translational stiffness parameters of the shock absorber (3) in the x-axis direction, y-axis direction and z-axis direction of the coordinate system.

3. The method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: In step XS2, the torque and angular displacement curves of the vibration absorber (3) rotating around the x-axis, y-axis and z-axis of the coordinate system are fitted with discrete points to obtain the torsional stiffness parameters of the vibration absorber (3) rotating around the x-axis, y-axis and z-axis of the coordinate system.

4. The method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: In step XS8, the vibration response value of the first point in step XS7 is calculated based on the vibration response value of the first point in step XS7. x 1 and the distance from the first point to the system vibration period T The vibration response value of the second point x 2. Obtain an equivalent viscous damping ratio of the shock absorber (3), and obtain six-degree-of-freedom damping parameters of the shock absorber (3) according to the equivalent viscous damping ratio.

5. The method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: The gyroscope (5) is located on the rotation axis of the counterweight turntable (6).

6. The method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: The first adapter bracket (9) is mounted on the upper stand (11).

7. The method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: The rotation axis of the counterweight rotating disk (6) coincides with the geometric center of the shock absorber (3).

8. The method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to claim 1, characterized in that: The rotating shaft (7) is mounted on the test bench base (4).

9. A method for simulating the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber, the method comprising all the steps of the method for measuring the six-degree-of-freedom nonlinear stiffness and damping of a shock absorber according to any one of claims 1 to 8, characterized in that: The simulation method further comprises the following steps: Step XS9, establishing a finite element simulation model of the optoelectronic pod product; Step XS10, finite element modeling is performed on the mounting and fixing ends of the shock absorber (3), a stiffness and damping connection unit (10) is established between the mounting and fixing ends of the shock absorber (3), and the stiffness and damping connection unit (10) is connected to the mounting and fixing ends of the shock absorber (3); Step XS11, assigning the translational stiffness parameters of the shock absorber (3) in the x-axis direction, y-axis direction and z-axis direction of the coordinate system, the torsional stiffness parameters of the shock absorber (3) rotating around the x-axis, y-axis and z-axis of the coordinate system, and the six-degree-of-freedom damping parameters of the shock absorber (3) to the stiffness damping connection unit (10), and performing finite element simulation calculation.

10. A six-degree-of-freedom nonlinear stiffness and damping simulation method for a shock absorber according to claim 9, characterized in that: The establishment of the finite element simulation model of the optoelectronic pod product includes finite element mesh division, connection relationship processing between components and material property assignment.

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