CN115062408A - Method for improving strength durability simulation precision of suspension support on elastic-damping integrated shock absorber - Google Patents

Abstract

The invention discloses a method for improving the strength endurance simulation precision of a suspension bracket on an integral shock absorber of an elastic damping, which comprises the steps of establishing a beam unit rigidity equivalent suspension system model; carrying out grid division; assigning material properties to the meshed assembled structure; establishing a contact relation; applying constraints; uniformly distributing loads on the first area and the second area; submitting a calculation result of strength durability calculation of a suspension bracket on the elastic-reduction integrated suspension shock absorber; verifying whether the deformation of the suspension system and the contact relation are correct or not according to the calculation result; the invention can accurately calculate the stress and strain of the upper suspension bracket of the elastic-damping integrated suspension shock absorber, and correctly guide the design of the upper suspension bracket, so that the strength and durability of the upper suspension bracket reach the standard.

Description

Method for improving strength durability simulation precision of suspension support on elastic-damping integrated shock absorber

Technical Field

The invention relates to the technical field of vehicle design analysis, in particular to a method for improving strength durability simulation precision of a suspension support on an integral damper.

Background

The double-wishbone type suspension and the macpherson type suspension are both in the form of a spring-damper integrated suspension, referred to as an elastic-damping integrated suspension for short. When the strength durability of the suspension bracket on the shock absorber of the suspension is calculated, the upper suspension bracket cannot reflect the real stress and strain under the structural working state due to unreasonable modeling method, constraint mode and loading mode, so that the development of the structural strength durability is influenced.

The existing upper suspension bracket strength calculation method has the following three problems: 1. when a simulation model is established, only the upper suspension bracket is established, the positions of the upper suspension bracket and the vehicle body fixing bolt are restrained by 1-6 degrees of freedom, the relative displacement between the bolt fixing points of the upper suspension bracket is not considered in the restraining mode, full restraint is adopted, and the vehicle body is deformed at the actual position, namely the bolt fixing points can move relatively; 2. the upper suspension bracket and the vehicle body are connected by adopting a fixed bolt, and a contact relation also exists, so that the current modeling mode is not considered; 3. when the coil spring upwards presses the upper suspension bracket through the upper gasket of the spring, the load is not uniformly distributed, the contact area is changed along with the change of the compression amount of the coil spring, and the current loading mode is not considered; 4. when the coil spring presses the upper suspension bracket upwards through the upper gasket of the spring, the load direction changes along with the compression of the spring, in particular to a Macpherson spring-damping integrated suspension system, a certain inclination angle exists in the initial state of the coil spring, and the current loading mode is not considered.

The above problems are urgently needed to be solved.

Disclosure of Invention

The invention aims to provide a method for improving the strength durability simulation precision of a suspension bracket on an elastic-damping integrated shock absorber, so as to solve the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: a method for improving the strength durability simulation precision of a suspension support on an elastic-damping integrated shock absorber comprises the following steps:

establishing a beam unit rigidity equivalent suspension system model;

performing meshing, wherein the assembly structure for performing meshing comprises an upper suspension bracket, a partial automobile body, a spring upper gasket, a spring lower tray and a spiral spring, and the partial automobile body is a cut part of the automobile body connected with the upper suspension bracket;

assigning material properties to the meshed assembled structure;

establishing a contact relationship, wherein the established contact relationship comprises: establishing a contact relation between the upper suspension bracket and a part of the vehicle body, establishing a contact relation between the upper spring liner and the upper suspension bracket, establishing a contact relation among the spiral spring, the upper spring liner and the lower spring liner, and establishing a contact relation between the lower spring liner and the lower spring tray;

applying constraints, and respectively constraining six degrees of freedom of the part of the vehicle body, an upper point of a shock absorber, an inner point of an upper control arm and a frame connection point, wherein the frame connection point is a connection point between an auxiliary frame and the vehicle body;

uniformly distributing loads on a first area and a second area, wherein the first area is an area where the upper suspension bracket is in contact with a limiting block, and the second area is an area where the upper suspension bracket is in contact with an upper rubber suspension;

submitting a calculation result of the strength durability calculation of the upper suspension bracket;

and verifying whether the deformation of the suspension system and the contact relation are correct or not according to the calculation result.

In the above embodiment, the six degrees of freedom respectively represent a vehicle coordinate system X direction, a vehicle coordinate system Y direction, a vehicle coordinate system Z direction, a forward rotation direction around an X axis, a forward rotation direction around a Y axis, and a forward rotation direction around a Z axis; the coordinate system of the whole vehicle points to the tail from the head of the vehicle and is in the positive direction of the X axis, the vertical direction is in the positive direction of the Z axis, and the Y axis accords with the right-hand spiral rule.

Further, judging whether the deformation and the contact relation of the suspension system are correct according to the calculation result, the method further comprises the following steps: and judging whether the suspension system is deformed and the contact relation is incorrect according to the calculation result, checking whether the contact relation is established correctly and adjusting according to the checking result, checking whether the applied constraint is correct and adjusting according to the checking result, checking whether the uniformly distributed load applied to the first area and the second area is correct and adjusting according to the checking result, submitting the calculation result of the strength endurance calculation of the upper suspension bracket again after readjusting, and judging whether the suspension system is deformed and the contact relation is correct according to the calculation result.

And further, judging that the deformation and the contact relation of the suspension system are correct according to the calculation result, and performing post-processing on the static simulation result of the upper suspension bracket.

Furthermore, a static simulation result is imported by combining with the faemfat software, the cycle number is input, and the endurance damage of the computational suspension bracket is calculated.

Further, writing a strength durability analysis report of the upper suspension bracket.

Further, the suspension system model is built according to a suspension system parameter table, wherein the system parameters include hard point coordinates, local coordinate system coordinates, and bushing stiffness.

Further, before the mesh division, the method further comprises: introducing a geometric model of the upper suspension bracket, a portion of the vehicle body, the upper spring liner, the lower spring tray, and the coil spring.

Further, imparting material properties to the meshed assembled structure includes: establishing and endowing the upper suspension bracket material with nonlinear properties.

And further, introducing the divided grids and the attribute models into the suspension system model, and deleting the beam units at the corresponding positions.

Further, exert the equipartition load to first region and second region, still include:

when the wheel jumps upwards, the limiting block upwards extrudes the first area which is in contact with the upper suspension bracket, uniformly distributed load is applied to the first area, the load is decomposed from multi-body load, and meanwhile, the load is upwards applied to the wheel center of the suspension system;

when the wheel jumps down, the upper rubber suspension downwards presses the second area contacted with the upper suspension bracket, uniform load is applied to the second area, the load is decomposed by multi-body load, and meanwhile, downward load is applied to the wheel center of the suspension system.

Compared with the prior art, the invention has the beneficial effects that: the invention can accurately calculate the stress and strain of the upper suspension bracket of the elastic-damping integrated suspension shock absorber, and correctly guide the design of the upper suspension bracket, so that the strength and durability of the upper suspension bracket reach the standard.

Drawings

FIG. 1 is a flowchart of a method for improving the strength durability simulation accuracy of a suspension bracket on an integral shock absorber for an elastic reduction according to an embodiment of the present invention;

FIG. 2 is a flowchart of the calculation of the strength durability of the suspension bracket on the lift-and-rebound integrated shock absorber according to the embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an integral damper for damping elasticity according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a finite element model of a beam unit stiffness equivalent double wishbone suspension system in an embodiment of the invention;

FIG. 5 is a schematic view of a finite element model of a suspension system with a single-side replacement double wishbone of the integral shock absorber of the embodiment of the invention;

FIG. 6 is a schematic view of a finite element model of a suspension system with a double wishbone replaced on one side by another shock absorber;

in the figure: 10. an integral shock absorber is sprung-damped; 20. a partial vehicle body; 30. an upper point of the shock absorber; 40. an upper control arm inner point; 50. a frame connection point; 60. an auxiliary frame; 70. a wheel center; 80. a lower control arm; 11. an upper suspension bracket; 12. a spring upper liner; 13. mounting a rubber suspension; 14. a limiting block; 15. a coil spring; 16. a lower spring liner; 17. a tray under the spring.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, "a plurality" means two or more unless otherwise specified; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention provides a correct and reasonable modeling and loading method, which can accurately calculate the stress and strain of an upper suspension bracket of an elastic-damping integrated shock absorber and correctly guide the design of the upper suspension bracket, so that the strength and durability of the upper suspension bracket reach the standard.

Referring to the attached drawings of the specification, the invention provides a technical scheme that: as shown in fig. 1, a method for improving the strength durability simulation precision of a suspension bracket on an integral damper for elastic reduction comprises the following steps:

s100, establishing a beam unit rigidity equivalent suspension system model;

s200, carrying out meshing, wherein the assembly structure for carrying out meshing comprises an upper suspension bracket 11, a partial automobile body 20, an upper spring pad 12, a lower spring pad 16, a lower spring tray 17 and a spiral spring 15, wherein the partial automobile body 20 is a cut partial automobile body connected with the upper suspension bracket 11;

s300, giving material properties to the assembly structure divided by the grids;

s400, establishing a contact relation, wherein the established contact relation comprises the following steps: establishing a contact relationship between the upper suspension bracket 11 and a part of the vehicle body 20, establishing a contact relationship between the upper spring pad 12 and the upper suspension bracket 11, establishing a contact relationship between the coil spring 15, the upper spring pad 12 and the lower spring pad 16, and establishing a contact relationship between the lower spring pad 16 and the lower spring tray 17;

s500, applying constraint to respectively constrain six degrees of freedom of the partial vehicle body 20, the upper point 30 of the shock absorber, the inner point 40 of the upper control arm and a frame connection point 50, wherein the frame connection point 50 is a connection point between the auxiliary frame 60 and the vehicle body;

s600, uniformly distributing loads on a first area and a second area, wherein the first area is an area where the upper suspension bracket 11 is in contact with the limiting block 14, and the second area is an area where the upper suspension bracket 11 is in contact with the upper rubber suspension 13;

s700, submitting a calculation result of strength endurance calculation of the upper suspension bracket 11;

and S800, judging whether the deformation and the contact relation of the suspension system are correct or not according to the calculation result.

In the above embodiment, as shown in fig. 4, in step S100, the equivalent suspension system model has all structures in the real suspension model, but all structures are equivalently replaced by beam units, and meanwhile, the equivalent suspension system model has the characteristics of small model scale and few units and nodes; as shown in fig. 5, step S500 constrains the cut-out portion of the vehicle body in six degrees of freedom, and, taking into account the vehicle body rigidity, releases the relative deformation space between the bolt fixing points, which are the upper suspension bracket 11 and the vehicle body fixing bolt, due to the vehicle body variability.

Optionally, as shown in fig. 2, the step S800 verifies whether the suspension system deformation and the contact relationship are correct according to the calculation result, and further includes: verifying that the suspension system is deformed and the contact relationship is incorrect according to the calculation result, checking whether the contact relationship is established correctly and adjusting according to the checking result, checking whether the applied constraint is correct and adjusting according to the checking result, checking whether the uniformly distributed load applied to the first area and the second area is correct and adjusting according to the checking result, re-adjusting, submitting the calculation result of the strength and durability calculation of the upper suspension bracket 11 again, and judging whether the suspension system is deformed and the contact relationship is correct according to the calculation result.

Alternatively, as shown in fig. 2, if step S800 determines that the suspension system is deformed and the contact relationship is correct according to the calculation result, the upper suspension bracket 11 performs post-processing on the static simulation result.

In the above embodiment, the result file calculated by the finite element solver is opened in the finite element post-processing software, the calculation result of the strength durability calculation of the upper suspension bracket 11 is checked, and it is determined whether the strength durability of the upper suspension bracket 11 can meet the standard, if not, the improvement is performed, otherwise, the strength durability meets the requirement, and the improvement is not required.

Alternatively, as shown in fig. 2, the static simulation result is imported in combination with the faemfat software, the number of cycles is input, and the endurance damage of the upper suspension support 11 is calculated.

In the above embodiment, the failfat software is a set of software capable of performing strength and fatigue analysis on static and dynamic load-loaded components based on finite element analysis results.

Alternatively, as shown in fig. 2, a report of the strength durability analysis of the upper suspension bracket 11 is written.

Optionally, the suspension system model is built according to a suspension system parameter table, wherein the system parameters include hard point coordinates, local coordinate system coordinates, and bushing stiffness.

Optionally, before performing the meshing, the method further includes: a geometric model of the upper suspension bracket 11, the part body 20, the upper spring liner 12, the lower spring liner 16, the lower spring tray 17 and the coil spring 15 is introduced.

Optionally, imparting material properties to the meshed assembled structure comprises: the non-linear properties of the material of the upper suspension bracket 11 are established and given.

Optionally, the divided grid and attribute model is imported into the suspension system model, and the beam units at the corresponding positions are deleted.

In the above embodiment, as shown in fig. 5 to 6, the shock absorber mounting structure mesh model is replaced on one side with the shock absorber equivalent to the beam unit in the suspension system model generated in the first step.

Optionally, the applying uniform load to the first region and the second region further includes:

when the wheel jumps upwards, the limiting block 14 presses the first area contacting with the upper suspension bracket 11 upwards to apply uniform load to the first area, the load is decomposed from multi-body load, and meanwhile, the load is applied upwards at the wheel center 70 of the suspension system;

when the wheel jumps down, the upper rubber suspension 13 presses the second area contacting with the upper suspension bracket 11 downwards, and applies uniform load to the second area, wherein the load is generated by multi-body load decomposition, and meanwhile, downward load is applied to the wheel center 70 of the suspension system.

A schematic diagram of a damper assembly model is shown in figure 3. The stressed state of the suspension bracket on the shock absorber is explained as follows: when the wheel jumps up and down, the upper sliding column and the lower sliding column of the shock absorber slide relatively. When the wheel jumps up, the lower sliding column of the shock absorber moves upwards relative to the upper sliding column, the lower sliding column can upwards extrude the limiting block 14, the limiting block 14 can apply pressure on the upper suspension support 11, meanwhile, the spiral spring 15 upwards extrudes the upper spring liner 12, the upper spring liner 12 applies pressure on the upper suspension support 11, the upper suspension support 11 is fixedly connected with the vehicle body through the fixing bolt, and meanwhile, the upper suspension support 11 is in contact relation with the vehicle body, namely, the upper suspension support 11 transfers load to the vehicle body through the fixing bolt and contact. When the wheel jumps down, the spiral spring 15 is usually in a compressed state, and the pressure load is still acted on the upper suspension bracket 11 upwards by extruding the spring upper gasket 12, except that the lower sliding column of the shock absorber does not extrude the limiting block 14 upwards, the limiting block 14 does not extrude the upper suspension bracket 11 upwards, but the upper sliding column of the shock absorber drives the upper rubber suspension 13 to extrude the upper suspension bracket 11 downwards;

in the above embodiment, as shown in fig. 3, 5 and 6, when the wheel jumps up, the limiting block 13 presses the upper suspension bracket 11 upward to apply an even load, the load is from multi-body load decomposition, and at the same time, a load is applied at the wheel center 70 of the suspension system, the load compresses the coil spring 15 through the lower control arm 80, and the coil spring 15 presses the upper suspension bracket 11 upward through the upper spring pad 12; when the wheel jumps down, the upper rubber suspension 13 presses the upper suspension bracket 11 area downwards to apply uniform load, the load is from multi-body load decomposition, meanwhile, a force load is applied to the suspension wheel center 70, the coil spring 15 still applies the load to the upper suspension bracket 11 through the spring upper liner 12, the compression amount of the coil spring 15 is different, and the contact area between the coil spring 15 and the spring upper liner 12 is changed along with the change of the compression amount of the coil spring 15, so that the loading method not only can accurately simulate the contact area between the coil spring 15 and the spring upper liner 12 and the magnitude of the transmission pressure, but also can accurately simulate the change of the load direction of the coil spring 15 caused by the offset load of the coil spring 15, therefore, a load is applied to the suspension system wheel center 70, and the contact area of the coil spring 15 and the sprung pad 12, the pressure load, and the biased state of the coil spring 15 are accurately simulated by the contact relationship, so that the pressure load is accurately transmitted to the upper suspension bracket 11.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. A method for improving the strength durability simulation precision of a suspension support on an elastic-damping integrated shock absorber is characterized by comprising the following steps:

establishing a beam unit rigidity equivalent suspension system model;

performing meshing, wherein the assembly structure for performing meshing comprises an upper suspension bracket, a partial automobile body, a spring upper gasket, a spring lower tray and a spiral spring, and the partial automobile body is a cut part of the automobile body connected with the upper suspension bracket;

assigning material properties to the meshed assembled structure;

establishing a contact relationship, wherein the established contact relationship comprises: establishing a contact relation between the upper suspension bracket and a part of the vehicle body, establishing a contact relation between the upper spring liner and the upper suspension bracket, establishing a contact relation among the spiral spring, the upper spring liner and the lower spring liner, and establishing a contact relation between the lower spring liner and the lower spring tray;

applying constraints, and respectively constraining 1-6 degrees of freedom of the part of the vehicle body, the upper point of the shock absorber, the inner point of the upper control arm and the connection point of the vehicle frame, wherein the connection point of the vehicle frame is the connection point between the auxiliary frame and the vehicle body;

uniformly distributing load on a first area and a second area, wherein the first area is an area where the upper suspension bracket is contacted with a limiting block, and the second area is an area where the upper suspension bracket is contacted with an upper rubber suspension;

submitting a calculation result of the strength endurance calculation of the upper suspension bracket;

and verifying whether the deformation of the suspension system and the contact relation are correct or not according to the calculation result.

2. The method for improving the simulation accuracy of the durability of the strength of the suspension bracket on the elastic-reduction integrated shock absorber according to claim 1, wherein the method for verifying whether the deformation and the contact relation of the suspension system are correct according to the calculation result further comprises the following steps: verifying that the suspension system is deformed and the contact relation is incorrect according to the calculation result, checking whether the contact relation is established correctly and adjusting according to the checking result, checking whether the applied constraint is correct and adjusting according to the checking result, checking whether the uniformly distributed load applied to the first area and the second area is correct and adjusting according to the checking result, submitting the calculation result of the strength endurance calculation of the upper suspension bracket again after readjusting, and verifying that the suspension system is deformed and the contact relation is correct according to the calculation result.

3. The method for improving the strength and durability simulation precision of the upper suspension bracket of the elastic-reduction integrated shock absorber as claimed in claim 2, wherein the upper suspension bracket static simulation result is processed after the calculation result verifies that the deformation and the contact relation of the suspension system are correct.

4. The method for improving the strength endurance simulation precision of the suspension bracket on the integral damper for elastic reduction according to claim 3, wherein static simulation results are introduced in combination with a faemfat software, cycle times are input, and endurance damage of the suspension bracket is calculated.

5. The method for improving the simulation accuracy of the strength durability of the upper suspension bracket of the elastic-damping integrated shock absorber as claimed in claim 4, wherein the analysis report of the strength durability of the upper suspension bracket is compiled.

6. The method for improving the strength durability simulation accuracy of the suspension bracket on the rebound-reducing integrated shock absorber as recited in claim 1, wherein the suspension system model is built according to a suspension system parameter table, wherein the system parameters comprise hard point coordinates, local coordinate system coordinates and bushing stiffness.

7. The method for improving the strength durability simulation accuracy of the suspension bracket on the elastic-damping integrated shock absorber according to claim 1, wherein before the gridding, the method further comprises: introducing a geometric model of the upper suspension bracket, a portion of the vehicle body, the upper spring liner, the lower spring tray, and the coil spring.

8. The method of improving the accuracy of a simulation of the durability of the strength of a suspension bracket on a sprung mass damper as recited in claim 7, wherein the imparting material properties to the latticed mounting structure includes: establishing and endowing the upper suspension bracket material with nonlinear properties.

9. The method for improving the strength and durability simulation accuracy of the suspension bracket on the integral damper for elastic reduction according to claim 1, wherein the divided grid and attribute models are introduced into the suspension system model, and the beam units at the corresponding positions are deleted.

10. The method for improving the simulation accuracy of the durability of the strength of the suspension bracket on the integral damper for elastic reduction according to claim 1, wherein the first region and the second region are uniformly loaded, and further comprising:

when the wheel jumps upwards, the limiting block upwards extrudes the first area which is in contact with the upper suspension bracket, and uniformly distributed load is applied to the first area, the load is derived from decomposition of multi-body load, and meanwhile, the load is upwards applied to the wheel center of the suspension system;

when the wheel jumps down, the upper rubber suspension downwards presses the second area contacted with the upper suspension bracket, uniform load is applied to the second area, the load is decomposed by multi-body load, and meanwhile, downward load is applied to the wheel center of the suspension system.

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