Frame assembly testing method

Abstract

The invention relates to the technical field of vehicle testing, and provides a frame assembly testing method, which comprises the following steps of: constructing a virtual rack based on simulation software; obtaining a frame flexible body model based on the frame assembly grid model; assembling the suspension dynamical model and the frame flexible body model into a frame assembly rigid-flexible coupling assembly; establishing a communication matching mechanism between the frame assembly rigid-flexible coupling assembly and the virtual rack; and applying a load corresponding to the typical working condition to the frame assembly rigid-flexible coupling assembly through the virtual rack, and testing the performance of the frame assembly rigid-flexible coupling assembly under the typical working condition. The virtual rack, the suspension dynamical model and the frame flexible body model are established through simulation software to obtain the frame assembly rigid-flexible coupling assembly, the load corresponding to the typical working condition is applied to the frame assembly rigid-flexible coupling assembly through the virtual rack, and the performance of the frame assembly rigid-flexible coupling assembly under various typical working conditions can be tested. And further, the fatigue life of the frame is accurately pre-judged.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle testing, and in particular to a vehicle frame assembly testing method. Background Art

[0002] At present, vehicles are widely used in people's daily life. The frame is the base platform of the whole vehicle, supporting and connecting various parts of the vehicle, and bearing various random loads from inside and outside the vehicle. The quality and performance of the frame directly affect the performance of the whole vehicle. The fatigue strength of the frame is a key indicator to assess the quality of the frame. Therefore, it is necessary to test and verify the fatigue strength of the frame.

[0003] In the prior art, the torsional fatigue bench test can only simulate a single frame torsion condition, which cannot truly reflect the actual stress conditions of the frame on the road, and thus cannot accurately predict the fatigue life of the frame. Summary of the invention

[0004] The present invention provides a frame assembly testing method, which is used to solve the defect in the prior art that the fatigue life of the frame cannot be accurately predicted.

[0005] The present invention provides a frame assembly testing method, comprising the following steps: Building a virtual test bench based on simulation software, wherein the virtual test bench is used to reproduce typical working conditions of the vehicle frame assembly; Obtaining a flexible body model of the vehicle frame based on a mesh model of the vehicle frame assembly; Assembling the suspension dynamics model and the frame flexible body model into a frame assembly rigid-flexible coupling assembly; Establishing a communication matching mechanism between the rigid-flexible coupling assembly of the vehicle frame assembly and the virtual test bench; The load corresponding to the typical working condition is applied to the rigid-flexible coupling assembly of the frame assembly through the virtual test bench to test the performance of the rigid-flexible coupling assembly of the frame assembly under the typical working condition.

[0006] According to a vehicle frame assembly testing method provided by the present invention, the step of obtaining a vehicle frame flexible body model based on a vehicle frame assembly grid model comprises: Establish the mesh model of the frame assembly based on the finite element method; Establishing external connection points on the frame assembly grid model; Generate a flexible body of a dynamics model from the frame assembly grid model; A vehicle frame flexible body model is established based on the flexible body.

[0007] According to a vehicle frame assembly testing method provided by the present invention, before assembling the suspension dynamics model and the vehicle frame flexible body model into a vehicle frame assembly rigid-flexible coupling assembly, the method further includes: The suspension dynamics model is established based on the multi-body dynamics method.

[0008] According to a vehicle frame assembly testing method provided by the present invention, the virtual bench includes a loading mechanism, and the loading mechanism includes at least one of a front vertical loading mechanism, a rear vertical loading mechanism, a front lateral loading mechanism, a rear lateral loading mechanism, and a longitudinal loading mechanism; The front vertical loading mechanism is used to apply vertical loads to the cab and the powertrain; The rear vertical loading mechanism is used to apply a vertical load from the trailer to the saddle or a vertical load from the upper body to the subframe; The front side loading mechanism is used to apply a side load to the steering axle; The rear side loading mechanism is used to apply the side load of the trailer to the saddle; The longitudinal loading mechanism is used to apply a longitudinal load to the frame assembly.

[0009] According to a vehicle frame assembly testing method provided by the present invention, the front vertical loading mechanism includes a front vertical actuator and a front cross beam, both ends of the front cross beam are overlapped on the vehicle frame flexible body model, and the upper end of the front vertical actuator is connected to the middle part of the front cross beam.

[0010] According to a vehicle frame assembly testing method provided by the present invention, the rear vertical loading mechanism comprises a rear cross beam and two rear vertical actuators, the rear cross beam is arranged on a saddle of the vehicle frame flexible body model, the two rear vertical actuators are located on both sides of the saddle and are respectively connected to the two ends of the rear cross beam, or, The rear vertical loading mechanism includes a rear crossbeam and a rear vertical actuator. The two ends of the rear crossbeam are overlapped on the upper wing surface of the rear part of the frame flexible body model, and the upper end of the rear vertical actuator is connected to the middle part of the rear crossbeam.

[0011] According to a vehicle frame assembly testing method provided by the present invention, the virtual test bench further includes a wheel actuator, and the wheel actuator is used to apply a displacement load to the suspension.

[0012] According to a vehicle frame assembly testing method provided by the present invention, the virtual test bench further includes a support member, and the support member is used to vertically support the wheels of the vehicle frame.

[0013] According to a vehicle frame assembly testing method provided by the present invention, before applying the load corresponding to the typical working condition to the vehicle frame assembly rigid-flexible coupling assembly through the virtual test bench, the method further includes: The initial posture of the virtual test bench is adjusted so that the rigid-flexible coupling assembly of the vehicle frame assembly is in an actual state corresponding to the vehicle frame assembly.

[0014] According to a vehicle frame assembly testing method provided by the present invention, after the virtual bench is constructed based on the simulation software, the method further includes: In the multi-axis test bench of the vehicle frame assembly, the standard working condition excitation of the test bench is used to simulate the working condition of the frame and obtain the measured response data; Inputting the standard working condition of the test bench into the virtual test bench to obtain virtual test bench response data; The virtual rig is adjusted based on the measured response data and the virtual rig response data so that an error requirement is met between the measured response data and the virtual rig response data.

[0015] The vehicle frame assembly testing method provided by the present invention establishes a virtual test bench through simulation software, obtains the rigid-flexible coupling assembly of the frame assembly through the suspension dynamics model and the frame flexible body model, and applies the load corresponding to the typical working condition to the rigid-flexible coupling assembly of the frame assembly through the virtual test bench. The performance of the rigid-flexible coupling assembly of the frame assembly under various typical working conditions can be tested, and the fatigue life of the frame can be accurately predicted. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the present invention or 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is one of the flow charts of the vehicle frame assembly testing method provided by the present invention.

[0018] Figure 2 It is a schematic diagram of the coordination between the rigid-flexible coupling assembly of the vehicle frame assembly and the virtual test bench provided by the present invention.

[0019] Figure 3 It is one of the structural schematic diagrams of the front vertical loading mechanism provided by the present invention.

[0020] Figure 4 This is the second structural schematic diagram of the front vertical loading mechanism provided by the present invention.

[0021] Figure 5 It is a structural schematic diagram of the rear vertical loading mechanism provided by the present invention.

[0022] Figure 6 It is a schematic diagram of the coordination of the front lateral loading mechanism and the front suspension dynamics model provided by the present invention.

[0023] Figure 7 It is a structural schematic diagram of the rear side loading mechanism provided by the present invention.

[0024] Figure 8 It is a structural schematic diagram of the longitudinal loading mechanism provided by the present invention.

[0025] Fig. 9 It is a structural schematic diagram of the vertical displacement actuator provided by the present invention.

[0026] Fig.10 It is a structural schematic diagram of the support member provided by the present invention.

[0027] Fig.11 It is a structural schematic diagram of the vehicle frame assembly grid model provided by the present invention.

[0028] Fig.12 It is a structural schematic diagram of the vehicle frame flexible body model provided by the present invention.

[0029] Fig.13 It is a structural schematic diagram of the front suspension dynamics model provided by the present invention.

[0030] Fig.14 It is a structural schematic diagram of the rear suspension dynamics model provided by the present invention.

[0031] Fig.15 This is the third flow chart of the vehicle frame assembly testing method provided by the present invention.

[0032] Fig.16 This is the fourth flow chart of the vehicle frame assembly testing method provided by the present invention.

[0033] Figure numerals: 1, front vertical loading mechanism; 101, front vertical actuator; 102, front cross beam; 103, bushing; 104, ball pair; 2, rear vertical loading mechanism; 201, rear vertical actuator; 202, rear cross beam; 3, front lateral loading mechanism; 301, front lateral actuator; 302, front connecting member; 4, rear lateral loading mechanism; 401, rear lateral actuator ; 5. Longitudinal loading mechanism; 501. Longitudinal actuator; 6. Support; 7. Frame flexible body model; 701. Saddle; 81. Front suspension dynamic model; 82. Rear suspension dynamic model; 801. Steering axle; 802. Front suspension stabilizer bar; 803. Front leaf spring; 804. Middle axle; 805. Rear axle; 806. Rear leaf spring; 9. Wheel actuator; 901. Vertical shift actuator. DETAILED DESCRIPTION

[0034] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of 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.

[0036] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0037] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0039] Combine the following Figure 1-Figure 16 A vehicle frame assembly testing method according to an embodiment of the present invention is described.

[0040] The embodiment of the present invention provides a frame assembly testing method, such as Figure 1 As shown, the vehicle frame assembly testing method includes the following steps 100 to 500.

[0041] Step 100: construct a virtual test bench based on simulation software, where the virtual test bench is used to reproduce typical working conditions of the vehicle frame assembly.

[0042] Step 200: Acquire a vehicle frame flexible body model based on the vehicle frame assembly grid model.

[0043] Step 300: Assemble the suspension dynamics model and the vehicle frame flexible body model into a vehicle frame assembly rigid-flexible coupling assembly.

[0044] Step 400: Establish a communication matching mechanism between the rigid-flexible coupling assembly of the vehicle frame assembly and the virtual test bench.

[0045] Step 500: Apply a load corresponding to a typical working condition to the rigid-flexible coupling assembly of the vehicle frame assembly through a virtual test bench to test the performance of the rigid-flexible coupling assembly of the vehicle frame assembly under the typical working condition.

[0046] It can be understood that a virtual test bench is established through simulation software to reproduce the typical working conditions of the frame; a frame flexible body model is established based on the frame assembly mesh model corresponding to the frame assembly, and the suspension dynamics model and the frame flexible body model corresponding to the frame assembly are assembled to obtain the frame assembly rigid-flexible coupling assembly; the load corresponding to the typical working conditions is applied to the frame assembly rigid-flexible coupling assembly through the virtual test bench to test the performance of the frame assembly rigid-flexible coupling assembly under typical working conditions.

[0047] The frame assembly testing method provided in the embodiment of the present invention establishes a virtual test bench through simulation software, obtains the frame assembly rigid-flexible coupling assembly through the suspension dynamics model and the frame flexible body model, and applies the load corresponding to the typical working condition to the frame assembly rigid-flexible coupling assembly through the virtual test bench. The performance of the frame assembly rigid-flexible coupling assembly under various typical working conditions can be tested, and the fatigue life of the frame can be accurately predicted.

[0048] According to an embodiment of the present invention, the virtual test bench is a multi-axis virtual test bench, which can realize the reproduction of various typical working conditions of the frame.

[0049] It should be noted that in the prior art, the fatigue test of the frame assembly mainly includes road simulation test and torsional fatigue bench test; among them, the road simulation test can only obtain the load spectrum of some attachment points of the frame, but cannot obtain the load of the global attachment points of the frame assembly, that is, it cannot accurately predict the service life and risk points of the structure. However, the multi-axis virtual bench of this embodiment can realize the reproduction of various typical working conditions of the frame, and can obtain the load of the global attachment points of the frame assembly for virtual verification of the product. At the same time, it can analyze the strain distribution of the frame under typical working conditions and clarify the stress sensitive areas of the frame under different typical working conditions.

[0050] It should be noted that the existing road simulation tests and torsional fatigue bench tests are all verified on real objects, which cannot be verified in the product development stage and cannot provide guidance for forward research and development. However, this embodiment designs the frame flexible body model and suspension dynamics model in the software, and creates a frame assembly rigid-flexible coupling assembly corresponding to the frame assembly through the suspension dynamics model and the frame flexible body model, and applies load to the frame assembly rigid-flexible coupling assembly through a virtual bench to achieve the reproduction of typical frame working conditions, obtain the load history under typical working conditions, and test the performance of the frame assembly rigid-flexible coupling assembly under various typical working conditions, so as to realize the performance test in the process of forward development of the frame assembly, and then realize virtual verification of rigid strength, durability, etc.; at the same time, it effectively saves manpower and time costs.

[0051] Optionally, the rigid-flexible coupling assembly of the frame assembly includes a frame flexible body model and a suspension dynamics model arranged on the frame flexible body model, the suspension dynamics model includes a front suspension dynamics model and a rear suspension dynamics model, the front suspension dynamics model is arranged on the front side of the frame flexible body model, and the rear suspension dynamics model is arranged on the rear side of the frame flexible body model, such as Fig.14 As shown, the rear suspension dynamics model 82 includes a middle bridge 804, a rear bridge 805 and a rear leaf spring 806. The virtual test bench can reproduce the real loads such as vehicle roll, braking, acceleration, etc., determine the installation position and constraint mode of each actuator, and clarify the position and function of each auxiliary support.

[0052] The virtual rig includes loading mechanisms such as Figures 2 to 4 As shown, the loading mechanism includes a front vertical loading mechanism 1, which is used to apply a vertical load and can apply a vertical load to the cab and the powertrain.

[0053] For example, the front vertical loading mechanism 1 includes a front vertical actuator 101 and a front cross beam 102 , both ends of the front cross beam 102 are overlapped on the front side of the frame flexible body model 7 , and the upper end of the front vertical actuator 101 is connected to the middle of the front cross beam 102 .

[0054] Specifically, Figure 3 and Figure 4As shown, there are three front vertical loading mechanisms 1 arranged at intervals along the first direction, the first direction is the front-to-back direction of the frame, the front vertical actuators 101 are arranged along the third direction, the third direction is the vertical direction, the upper end of the front vertical actuator 101 is connected to the front crossbeam 102 through a revolute pair, the lower end of the front vertical actuator 101 is connected to the ground through a ball pair 104, the two ends of the front crossbeam 102 are overlapped on the upper wing surface of the frame flexible body model 7, and the end of the front crossbeam 102 and the upper wing surface are connected through a bushing 103. It should be noted here that the front vertical loading mechanism 1 can be one, two or more, and the specific number is reasonably designed according to the front size of the frame flexible body model 7; in addition, the spacing between the front vertical loading mechanisms 1 can be evenly distributed, and the specific spacing can also be reasonably designed according to the front size of the frame flexible body model 7.

[0055] Optionally, the loading mechanism includes a rear vertical loading mechanism 2, and the rear vertical loading mechanism 2 is used to apply a vertical load from the trailer to the saddle 701 or to apply a vertical load from the upper body to the sub-frame.

[0056] It can be understood that, for tractor vehicles, the rear vertical loading mechanism 2 can apply the vertical load of the trailer to the saddle 701; for trucks and engineering vehicles, the rear vertical loading mechanism 2 can apply the vertical load of the upper body to the subframe.

[0057] For example, Figure 2 and Figure 5 As shown, for the tractor type, the rear vertical loading mechanism 2 on the saddle 701 of the frame flexible body model 7 includes two rear vertical actuators 201 and a rear cross beam 202. The two rear vertical actuators 201 are distributed on the left and right sides of the saddle 701 along the second direction. The second direction is the left and right direction of the frame, that is, the two rear vertical actuators 201 are distributed on the left and right sides of the saddle 701; the rear cross beam 202 is fixedly connected to the top of the saddle 701, and the two ends of the rear cross beam 202 are connected to the upper ends of the two rear vertical actuators 201 through ball joints, and the lower end of the rear vertical actuator 201 is connected to the ground through a ball joint.

[0058] For trucks and engineering vehicles, the rear vertical loading mechanism 2 can adopt the same structure as the front vertical loading mechanism 1. The rear vertical loading mechanism 2 on the frame flexible body model 7 includes a rear vertical actuator and a rear cross beam. The upper end of the rear vertical actuator is connected to the rear cross beam through a rotating pair, and the lower end of the rear vertical actuator is connected to the ground through a ball pair. The two ends of the rear cross beam are mounted on the upper wing surface at the rear of the frame flexible body model 7; there can be four rear vertical loading mechanisms 2, and the four rear vertical loading mechanisms 2 are distributed according to the spacing of the rear size of the frame.

[0059] Optionally, the front suspension dynamics model 81 includes a steering axle 801, and the loading mechanism includes a front lateral loading mechanism 3, and the front lateral loading mechanism 3 can apply a lateral load to the steering axle 801. It should be noted here that the number of the front lateral loading mechanisms 3 is equal to the number of the steering axles 801 of the front suspension dynamics model 81, and the positions correspond one to one.

[0060] For example, Fig.13 As shown, the front suspension dynamics model 81 includes a front suspension stabilizer bar 802, a front leaf spring 803 and a steering axle 801. Figure 2 and Figure 6 As shown, the front lateral loading mechanism 3 includes a front lateral actuator 301, which is arranged along the second direction, one end of the front lateral actuator 301 is connected to the axle head, and the other end of the front lateral actuator 301 is connected to the ground through a ball joint.

[0061] Furthermore, when the installation space of the front lateral actuator 301 is limited, the front lateral loading mechanism 3 further includes a front connecting member 302 , and the front lateral actuator 301 is connected to the axle head through the front connecting member 302 .

[0062] Optionally, the loading mechanism includes a rear side loading mechanism 4 , which is capable of applying a side load of the trailer to the saddle 701 .

[0063] For example, Figure 2 and Figure 7 As shown, the rear lateral loading mechanism 4 includes a rear lateral actuator 401, which is arranged along the second direction, one end of the rear lateral actuator 401 is connected to the saddle 701, and the other end of the rear lateral actuator 401 is connected to the ground through a ball joint.

[0064] Further, the rear lateral loading mechanism 4 also includes a rear connecting member, through which the rear lateral actuator 401 is connected to the saddle 701. It should be noted that the rear connecting member can be replaced by the rear cross beam 202, and one end of the rear lateral actuator 401 is connected to one end of the rear cross beam 202.

[0065] Optionally, the loading mechanism includes a longitudinal loading mechanism 5, which can apply a longitudinal load to the frame assembly.

[0066] For example, Figure 2 and Figure 8 As shown, for the tractor, the longitudinal loading mechanism 5 includes a longitudinal actuator 501, which is arranged along a first direction, one end of the longitudinal actuator 501 is connected to the saddle 701, and the other end of the longitudinal actuator is connected to the ground through a ball joint.

[0067] Furthermore, the longitudinal loading mechanism 5 further comprises a longitudinal connecting member, through which the longitudinal actuator 501 is connected to the saddle 701. It should be noted that the longitudinal connecting member can be replaced by the rear cross beam 202, and one end of the longitudinal actuator 501 is connected to the middle of the rear cross beam 202.

[0068] For trucks and engineering vehicles, the longitudinal loading mechanism 5 can be directly connected to the flexible body of the vehicle frame at the tail beam.

[0069] Optionally, the virtual test bench further includes a wheel actuator 9, and the wheel actuator 9 is used to apply a displacement load to the suspension. Then, the wheel actuator 9 can apply a forced displacement load to the suspension.

[0070] For example, Figure 2 and Fig. 9 As shown, the wheel actuator 9 includes a plurality of vertical displacement actuators 901 arranged along the third direction, the two ends of the steering axle 801 are connected to the upper ends of the vertical displacement actuators 901 through ball joints, and the lower ends of the vertical displacement actuators 901 are connected to the ground through ball joints; the two ends of the air suspension structure rear axle are also connected to the vertical displacement actuators 901 through ball joints. It should be noted here that the number of vertical displacement actuators 901 depends on the number of steering axles 801 and air suspension structure rear axles.

[0071] It should be noted that the number, installation position, loading method and constraint method of each actuator in the virtual test bench are adaptively increased, decreased and moved according to different types of frame assemblies.

[0072] Optionally, the virtual test bench also includes a support member 6, which mainly includes an auxiliary support for simulating tire support reaction force, roll force, and return moment, and a simulated support for simulating overturning moment of working conditions such as vehicle bridge encountering obstacles and braking; Figure 2 and Fig.10 As shown, the support member 6 is used to vertically support the wheels of the frame.

[0073] It can be understood that the function of the support member 6 is to establish vertical support for the wheel not connected to the vertical actuator; to establish lateral support for the axle not connected to the lateral actuator; to establish longitudinal support for the axle of the rear suspension; and to increase vertical support for the saddle 701.

[0074] It should be noted that the support members 6 in the virtual test bench can optimize the test bench boundary and avoid redundant loading with the actuator; the number, position, functional role, installation position and constraint method of the support members 6 in the virtual test bench can be adaptively increased, decreased and moved according to different types of frame assemblies.

[0075] In an optional embodiment of the present invention, the virtual gantry is established in the dynamics software, and the modeling method of the virtual gantry specifically includes the following steps: S1. Establish a front vertical loading mechanism that can apply vertical loads to the cab and powertrain.

[0076] S2. Establish a rear vertical loading mechanism. For tractor vehicles, it can apply a vertical load from the trailer to the saddle; for trucks and engineering vehicles, it can apply a vertical load from the upper body to the subframe.

[0077] S3. Establish a front lateral loading mechanism capable of applying lateral load to the steering axle.

[0078] S4. Establish a rear side loading mechanism capable of applying the side load of the trailer to the saddle.

[0079] S5. Establish a longitudinal loading mechanism capable of applying the longitudinal load of the frame assembly.

[0080] S6. Establish a wheel actuator that can apply a forced displacement load to the suspension.

[0081] S7. Create support parts.

[0082] S8. Establish a force response channel at the connection point between the loading mechanism and the support member, and establish a displacement response channel on each actuator.

[0083] It can be understood that the virtual test bench of this embodiment can be used to measure the inter-axle and front suspension and rear suspension bending and torsional stiffness of the frame flexible body model, thereby realizing virtual measurement of the frame assembly. In addition, by reproducing the typical working conditions of the frame through the virtual test bench of this embodiment, the stress conditions of each actuator and the virtual test bench can be analyzed, and the load data can be quantified to evaluate the frame assembly design at all stages of the entire product development, guiding the iterative optimization of the structure, and providing technical support for the design and transformation of the frame assembly.

[0084] It should be noted that the synergistic effect of the loading mechanism of the virtual test bench in this embodiment can realize the loading of random loads, and the coupling effect of random loads and the multi-degree-of-freedom frame system produces complex alternating loads, which directly affects the service life of the frame assembly. Therefore, the virtual test bench in this embodiment can simulate complex alternating loads and can achieve accurate prediction of the service life of the frame assembly.

[0085] According to an embodiment of the present invention, the frame assembly is simplified according to the force transmission characteristics. The frame assembly includes a frame, a front suspension, a rear suspension and related accessories. Therefore, models corresponding to the frame, the front suspension and the rear suspension are respectively constructed in the software. It should be noted that the degree of simplification of the frame assembly can be increased or decreased according to different test objectives.

[0086] In one embodiment of the present invention, Fig.15As shown, step 200, obtaining a vehicle frame flexible body model based on a vehicle frame assembly grid model, that is, the process of establishing a vehicle frame flexible body model corresponding to the vehicle frame specifically includes the following steps 210 to 240.

[0087] Step 210: Establish a frame assembly mesh model based on a finite element method.

[0088] It can be understood that the finite element method is used to establish the frame assembly mesh model in the finite element software, such as Fig.11 As shown, the frame assembly mesh model includes all longitudinal beams, cross beams, suspension mounting brackets, related accessories and corresponding connecting parts.

[0089] It should be noted that, for trucks and engineering vehicles, the frame assembly grid model also includes a subframe connected to the frame body; wherein the frame body includes a frame structure composed of longitudinal beams and transverse beams.

[0090] Step 220: Establish external connection points on the vehicle frame assembly grid model.

[0091] It can be understood that a number of external connection points for applying uniform loads are established on the left and right longitudinal beams, which are symmetrically distributed, and the number is adapted to the virtual bench vertical loading mechanism (front vertical loading mechanism and rear vertical loading mechanism), and the positions correspond one to one; external connection points are established at the suspension mounting bracket. It should be noted here that for tractors, external connection points are established at the saddle.

[0092] Step 230: Generate a flexible body of a dynamics model from the vehicle frame assembly mesh model.

[0093] Step 240: Establish a flexible body model of the vehicle frame based on the flexible body.

[0094] It can be understood that the frame assembly mesh model is imported into the multi-body dynamics software to generate a flexible body for the multi-body dynamics model, the flexible body retains stress and strain information, and the frame flexible body model 7 corresponding to the flexible body is established, such as Fig.12 shown.

[0095] In one embodiment of the present invention, before step 300, assembling the suspension dynamics model and the frame flexible body model into a frame assembly rigid-flexible coupling assembly, the testing method further includes the following steps: Step 600: Establish a suspension dynamics model based on a multi-body dynamics method.

[0096] Specifically, in the multi-body dynamics software, the suspension dynamics models corresponding to the tractor, truck and engineering vehicle are established, such as Fig.13 and Fig.14As shown, the suspension dynamics model includes a front suspension dynamics model 81 and a rear suspension dynamics model 82, and a connection point is established on the axle of the suspension dynamics model, and the connection point is adapted to the loading mechanism of the virtual test bench.

[0097] In one embodiment of the present invention, step 300, assembling the suspension dynamics model and the frame flexible body model into a frame assembly rigid-flexible coupling assembly specifically includes: A communication and matching mechanism is established among the virtual test bench, the frame flexible body model, and the suspension dynamics model, so that the corresponding connection points of each part can be automatically connected during assembly; the front suspension dynamics model and the rear suspension dynamics model are assembled to the frame flexible body model to obtain a rigid-flexible coupling assembly of the frame assembly, and the rigid-flexible coupling assembly of the frame assembly is assembled in the virtual test bench.

[0098] In one embodiment of the present invention, before step 500, in which a load corresponding to a typical working condition is applied to the rigid-flexible coupling assembly of the vehicle frame assembly through a virtual test bench, the testing method further comprises the following steps: Step 700: Adjust the initial posture of the virtual test bench so that the rigid-flexible coupling assembly of the vehicle frame assembly is in an actual state corresponding to the vehicle frame assembly.

[0099] It can be understood that the initial postures of the actuators of the virtual test bench loading mechanism are adjusted based on the measured axle load minus the weight of the unassembled frame assembly rigid-flexible coupling assembly on the virtual test bench, so that the frame assembly rigid-flexible coupling assembly is in an actual state corresponding to the frame assembly.

[0100] In one embodiment of the present invention, in step 500, testing the performance of the rigid-flexible coupling assembly of the vehicle frame assembly under the typical working conditions specifically includes the following working conditions: a. Bending conditions The actuator is driven to move, so that the vertical loading mechanism (front vertical loading mechanism, rear vertical loading mechanism) increases the appropriate downward load, and the wheel actuator generates an increased upward load. The size and distribution of each load can be adjusted according to the actual bending working condition mode.

[0101] b. Reversal conditions The vertical loading mechanism is kept preloaded, and the wheel actuator is driven to load the wheels on the same axle in different phases. It should be noted here that when the rigid-flexible coupling assembly of the frame assembly has multiple axle arrangement actuators, the diagonal loading between the axles is maintained.

[0102] c. Braking conditions The rear vertical loading mechanism is kept preloaded, and the front vertical loading mechanism is added with a downward vertical load, and a load in the driving direction is applied to the frame through the longitudinal actuator.

[0103] d. Turning conditions Keep the vertical loading mechanism preloaded, drive the lateral actuator, and load the front and rear actuators (front lateral loading mechanism, rear lateral loading mechanism) in the same phase.

[0104] It should be noted that the virtual test bench includes but is not limited to reproducing the loading of bending conditions, torsion conditions, braking conditions and turning conditions.

[0105] In one embodiment of the present invention, after step 100, building a virtual bench based on simulation software, the testing method further includes the following steps: Step 800: calibrate the virtual test bench with the multi-axis test bench of the vehicle frame assembly.

[0106] Optional, such as Fig.16 As shown, step 800 includes the following steps 810 to 830.

[0107] Step 810: In a multi-axis test bench for a vehicle frame assembly, a vehicle frame working condition simulation is performed using the test bench standard working condition excitation to obtain measured response data.

[0108] Step 820: Input the test bench standard working condition into the virtual test bench to obtain the virtual test bench response data.

[0109] Step 830: Adjust the virtual bench based on the measured response data and the virtual bench response data so that the error requirement between the measured response data and the virtual bench response data is satisfied.

[0110] It can be understood that, first, in the multi-axis test bench of the frame assembly, the typical working conditions of the frame are simulated by using the test bench standard working condition excitations that synthesize multiple sets of multi-axis sinusoidal waves with phase, and the strain responses of key positions of the frame (such as the wing and belly surfaces of the frame longitudinal beams, and the frame cross beams) are collected to obtain the measured response data of the frame assembly test bench under various working conditions; then, in the virtual test bench, the test bench standard working conditions are input into the virtual test bench to obtain the virtual test bench response data of the frame assembly under various working conditions, and the loads of the global attachment points of the output frame assembly are simulated and analyzed; the time domain stress curves or stress values ​​at a certain moment of the measured response data and the virtual test bench response data are compared. If the error value is large, the frame assembly and the virtual test bench are adjusted so that the error requirements between the measured response data and the virtual test bench response data are met.

[0111] It should be noted that the response signals such as frame acceleration and suspension displacement can also be used for benchmarking during the calibration of the virtual test bench and the multi-axis test bench of the frame assembly.

[0112] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A frame assembly testing method, It is characterized in that include: Building a virtual test bench based on simulation software, wherein the virtual test bench is used to reproduce typical working conditions of the vehicle frame assembly; Obtaining a flexible body model of the vehicle frame based on a mesh model of the vehicle frame assembly; Assembling the suspension dynamics model and the frame flexible body model into a frame assembly rigid-flexible coupling assembly; Establishing a communication matching mechanism between the rigid-flexible coupling assembly of the vehicle frame assembly and the virtual test bench; The load corresponding to the typical working condition is applied to the rigid-flexible coupling assembly of the frame assembly through the virtual test bench to test the performance of the rigid-flexible coupling assembly of the frame assembly under the typical working condition.

2. The vehicle frame assembly testing method according to claim 1, It is characterized in that The step of obtaining a vehicle frame flexible body model based on a vehicle frame assembly grid model includes: Establish the mesh model of the frame assembly based on the finite element method; Establishing external connection points on the frame assembly grid model; Generate a flexible body of a dynamics model from the frame assembly grid model; A vehicle frame flexible body model is established based on the flexible body.

3. The vehicle frame assembly testing method according to claim 1, It is characterized in that Before assembling the suspension dynamics model and the vehicle frame flexible body model into a vehicle frame assembly rigid-flexible coupling assembly, the method further includes: The suspension dynamics model is established based on the multi-body dynamics method.

4. The vehicle frame assembly testing method according to claim 1, It is characterized in that The virtual gantry includes a loading mechanism, and the loading mechanism includes at least one of a front vertical loading mechanism, a rear vertical loading mechanism, a front lateral loading mechanism, a rear lateral loading mechanism, and a longitudinal loading mechanism; The front vertical loading mechanism is used to apply vertical loads to the cab and the powertrain; The rear vertical loading mechanism is used to apply a vertical load from the trailer to the saddle or a vertical load from the upper body to the subframe; The front side loading mechanism is used to apply a side load to the steering axle; The rear side loading mechanism is used to apply the side load of the trailer to the saddle; The longitudinal loading mechanism is used to apply a longitudinal load to the frame assembly.

5. The vehicle frame assembly testing method according to claim 4, It is characterized in that The front vertical loading mechanism comprises a front vertical actuator and a front cross beam, the two ends of the front cross beam are overlapped on the frame flexible body model, and the upper end of the front vertical actuator is connected to the middle part of the front cross beam.

6. The vehicle frame assembly testing method according to claim 4, It is characterized in that The rear vertical loading mechanism comprises a rear cross beam and two rear vertical actuators, wherein the rear cross beam is arranged on the saddle of the frame flexible body model, and the two rear vertical actuators are located on both sides of the saddle and are respectively connected to the two ends of the rear cross beam, or, The rear vertical loading mechanism includes a rear crossbeam and a rear vertical actuator. The two ends of the rear crossbeam are overlapped on the upper wing surface of the rear part of the frame flexible body model, and the upper end of the rear vertical actuator is connected to the middle part of the rear crossbeam.

7. The vehicle frame assembly testing method according to claim 4, It is characterized in that The virtual test bench also includes a wheel actuator, which is used to apply a displacement load to the suspension.

8. The vehicle frame assembly testing method according to claim 4, It is characterized in that The virtual platform also includes a support member, which is used to vertically support the wheels of the frame.

9. The vehicle frame assembly testing method according to any one of claims 1 to 8, It is characterized in that Before applying the load corresponding to the typical working condition to the rigid-flexible coupling assembly of the vehicle frame assembly through the virtual test bench, the method further includes: The initial posture of the virtual test bench is adjusted so that the rigid-flexible coupling assembly of the vehicle frame assembly is in an actual state corresponding to the vehicle frame assembly.

10. The vehicle frame assembly testing method according to any one of claims 1 to 8, It is characterized in that After the virtual bench is constructed based on the simulation software, the method further comprises: In the multi-axis test bench of the vehicle frame assembly, the standard working condition excitation of the test bench is used to simulate the working condition of the frame and obtain the measured response data; Inputting the standard working condition of the test bench into the virtual test bench to obtain virtual test bench response data; The virtual rig is adjusted based on the measured response data and the virtual rig response data so that an error requirement is met between the measured response data and the virtual rig response data.

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