Contact simulation analysis method for cab rollover protection structure
By using a contact simulation analysis method, the problem of non-convergence in the static calculation of the cab rollover protection structure was solved, the simulation calculation efficiency was improved, and a universal and efficient simulation analysis was achieved, which is applicable to the design of various cab models.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGSU XCMG STATE KEY LAB TECH CO LTD
- Filing Date
- 2022-12-01
- Publication Date
- 2026-05-29
AI Technical Summary
In the simulation analysis of the cab anti-rollover protection structure, the existing technology is not easy to converge in static calculation, and is affected by factors such as structure, materials, shock absorbers, and constraints, resulting in low simulation calculation efficiency and lack of universality.
The contact simulation analysis method is adopted. By performing finite element modeling of the cab, setting up contact plates to perform unidirectional displacement loading under dynamic conditions, predicting loading force and energy demand, forming a new cab model, and performing triaxial loading to evaluate safety performance.
It improves simulation calculation efficiency, solves the problem of non-convergence in static calculation, has versatility, is not affected by factors such as structure, materials, and shock absorbers, and is suitable for different models of cab design.
Smart Images
Figure CN115809579B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of engineering machinery cabs and relates to a contact simulation analysis method for a cab anti-rollover protection structure. Background Technology
[0002] With the deepening of mechanization, cab safety has received increasing attention. In developed countries such as Europe and the United States, cab safety is a mandatory certification. In China, in the first half of 2021, the National Technical Committee for Standardization of Earthmoving Machinery convened a meeting of the "Mandatory National Standard Working Group for the 'Technical Specification for Safety of Earthmoving Machinery'," aiming to strongly promote cab safety standards. Currently, many cabs have insufficient or redundant safety features.
[0003] When performing simulation analysis on the protective structure of the cab of construction machinery, simulation engineers typically use software to build a finite element model. They then set constraints on the model according to standards (GB / T 17922-2014, ISO 3471-2008) and perform simulation calculations under static conditions. Afterwards, the simulation results (displacement-load curves, displacement-energy curves) are extracted and compared with the requirements specified in the standards. If the requirements are not met, the cab protective structure needs to be optimized, and the simulation analysis repeated until the standard requirements are met. However, simulation calculations of the cab protective structure under static conditions are easily affected by factors such as structure, materials, shock absorbers, and constraints, leading to significant difficulties in convergence. Furthermore, the solutions to convergence problems are highly dependent on the model and lack universality. Simulation engineers need to spend a considerable amount of time solving model calculation convergence problems, severely impacting work efficiency. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a contact simulation analysis method for the anti-rollover protection structure of the cab, which solves the problem of difficult convergence of static calculations and is applicable to the anti-rollover design of cabs of different models of engineering machinery.
[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:
[0006] A contact simulation analysis method for a cab rollover protection structure includes the following steps:
[0007] Finite element modeling was performed on the cab to obtain the cab model, and the nonlinear mechanical properties of the materials of each structural component of the cab were input into the cab model;
[0008] In the power display state, the cab model is subjected to unidirectional full displacement loading in different directions;
[0009] Based on the results of unidirectional full displacement loading, estimate the displacement values required to achieve the standard requirements in different directions using the loading force and energy.
[0010] A contact plate for loading in different directions is added to the top of the cab model to form a new cab model;
[0011] Based on the estimated displacement values in different directions, the new cab model is loaded in different directions in sequence;
[0012] The results of loading in different directions are analyzed to evaluate the safety performance of the cab.
[0013] Optionally, the contact plate includes a mounting plate, a top plate, a back plate, and side plates. The top plate is located above the cab, the back plate is located behind the cab, and the side plates are located on both sides of the cab. The edges of the mounting plate, back plate, and side plates are respectively connected to the edges of the top plate, and the mounting plate is inserted into the top of the cab.
[0014] Optionally, the contact plate has a density ≤1×10 -9 t / mm 3 Elastic modulus ≥ 4 × 10 5 Rigid materials with a pressure of MPa.
[0015] Optionally, the back panel and side panels are grooved, with the grooves of the back panel and side panels pointing towards the cab.
[0016] Optional, different directions include vertical, lateral and longitudinal.
[0017] Optionally, the cab model can be loaded laterally, vertically, and longitudinally in sequence.
[0018] Optionally, the cab model can be loaded in different directions sequentially, including loading and unloading.
[0019] Optional, loading includes:
[0020] In the power display state, the contact plate of the new cab model is forcibly displaced in one direction. The contact plate continuously approaches the cab, causing the cab to deform until it contacts the top of the cab.
[0021] Optional, uninstallation includes:
[0022] When the contact plate is subjected to a forced displacement equal to or opposite to the loading direction, the elastic deformation of the cab gradually recovers. Once the elastic deformation of the cab is fully recovered, the plastic deformation cannot be recovered. Under the action of the forced displacement, the contact plate continues to move and finally returns to the initial loading position.
[0023] Optionally, in a zero-gravity state, the cab model can be loaded in different directions sequentially.
[0024] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:
[0025] This invention provides a contact simulation analysis method for the anti-rollover protection structure of a driver's cab. This method performs load calculations on the anti-rollover protection structure of the driver's cab, eliminating the need for simulation engineers to spend time solving the problem of non-convergence in static calculations, thus greatly improving the efficiency of simulation calculations. Moreover, this method is not limited to a specific driver's cab and is not affected by factors such as structure, materials, shock absorbers, and constraints, making it highly versatile. Attached Figure Description
[0026] Figure 1 The flowchart shown is a flowchart of the present invention;
[0027] Figure 2 The diagram shown is a schematic diagram of the three-phase loading of the present invention;
[0028] Figure 3 The diagram shown is a schematic of the contact plate of the present invention;
[0029] Figure 4 As shown Figure 2 Side view of the middle contact plate.
[0030] In the diagram: 1. Tooling base plate; 2. Cab; 3. Fixed tooling; 4. Contact plate; 41. Side plate; 42. Back plate; 43. Top plate; 44. Mounting plate. Detailed Implementation
[0031] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.
[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0034] like Figure 1 and Figure 4 As shown, a contact simulation analysis method for a cab rollover protection structure includes the following steps:
[0035] S1. Finite element modeling of the cab is performed to obtain the cab model. The cab structure material is Q345. Material plasticity data is obtained through material testing, and the nonlinear mechanical properties of the materials of each structural component of the cab are input into the model. The tooling base plate 1 is fixed, and the cab 2 is connected to the tooling base plate 1 through the fixed tooling 3.
[0036] S2, in the dynamic calculation mode, the dynamic running model is subjected to unidirectional full displacement loading three times, namely lateral, vertical and longitudinal loading;
[0037] Based on the results of unidirectional full displacement loading, the dynamic loading in S2 with a loading distance of 500mm is estimated. The required displacement values for energy and loading force are shown in Table 1.
[0038] Table 1 Displacement values under unidirectional loading
[0039] Lateral (bidirectional) vertical direction Vertical Preload / mm 500 500 500 Standard value / mm 388 / 392 52 286
[0040] In Table 1, the value 388mm represents a lateral load of 388mm to meet the force requirement; the value 392mm represents a lateral load of 392mm to meet the force requirement; the value 52mm represents a vertical load of 52mm to meet the force requirement; and the value 286mm represents a longitudinal load of 286mm to meet the force requirement.
[0041] S4, modify the model established in S1. A contact plate 4 for loading in different directions is added to the top of the cab 2 model, forming a new cab model. The contact plate 4 includes a mounting plate 44, a top plate 43, a back plate 42, and side plates 41. The top plate 43 is located above the cab 2, the back plate 42 is located at the back of the cab 2, and the side plates 41 are located on both sides of the cab 2. The edges of the mounting plate 44, back plate 42, and side plates 41 are respectively connected to the edges of the top plate 43. The mounting plate 44 is vertically inserted into the top of the cab 2. The back plate 42 and side plates 41 are respectively grooved, with the groove openings of the back plate 42 and side plates 41 pointing towards the cab 2. During loading, the grooved side plates 41 and longitudinal plates 42 can be locked onto the top of the cab 2 to prevent slippage and detachment. If necessary, the inner groove bottoms of the side plates 41 and longitudinal plates 42 can be respectively connected to... Frictional contact between the outer surfaces of the cab 2; the shorter the distance between the inner bottom of the side plate 41 and the longitudinal plate 42 and the outer surface of the cab 2, the more accurate the lateral and longitudinal simulation. It is recommended that the actual gap distance not exceed 3mm; the distance between the inner surface of the top plate 43 and the vertical outer surface of the cab 2 is not less than 30mm. This can avoid the problem of collision or contact with the top plate 43 caused by the deformation of the cab 2 protective structure after lateral or longitudinal loading, which would lead to local reinforcement of the top of the cab 2. If necessary, frictional contact can be set between the inner surface of the top plate 43 and the vertical outer surface 23 of the cab 2 to prevent sliding; the contact plate 4 is a rigid material with very low density and very high elastic modulus, which can weaken the influence of the load distributor on the local reinforcement of the cab and make the simulation results more in line with reality. The parameters of the contact plate 4 are shown in Table 2.
[0042] Table 2 Recommended values for attributes
[0043] <![CDATA[ρ(t / mm 3 )]]> e / Mpa T / mm <![CDATA[1×10 -9 ]]> <![CDATA[4×10 5 ]]> 20
[0044] S5, based on the preloaded displacements in three directions, applies triaxial loading to the model modified in S3 under zero gravity conditions, such as... Figure 2 Three-way loading includes:
[0045] In the dynamic calculation mode, the side plate 41 of the dynamic model is subjected to a forced displacement only in the lateral direction. The side plate 41 continuously approaches the cab 2, and the cab 2 deforms until it contacts the top of the cab 2. The side plate 41 is subjected to a forced displacement of equal value and opposite to the loading direction. The elastic deformation of the cab 2 gradually recovers. The elastic deformation of the cab 2 is completely recovered, but the plastic deformation cannot be recovered. The side plate 41 continues to move under the action of the forced displacement and finally returns to the initial loading position.
[0046] A forced displacement is applied to the top plate 43 of the dynamic model in a lateral direction only. The top plate 43 moves closer to the cab 2, causing the cab 2 to deform until it contacts the top of the cab 2. A forced displacement is applied to the top plate 43 in the opposite direction to the loading direction. The elastic deformation of the cab 2 gradually recovers. The elastic deformation of the cab 2 is completely recovered, but the plastic deformation cannot be recovered. The top plate 43 continues to move under the action of the forced displacement and finally returns to the initial loading position.
[0047] A forced displacement is applied to the back plate 42 of the dynamic model in a lateral direction only. The back plate 42 moves closer to the cab 2, and the cab 2 deforms until it contacts the top of the cab 2. A forced displacement is applied to the back plate 42 in the opposite direction to the loading direction. The elastic deformation of the cab 2 gradually recovers. The elastic deformation of the cab 2 is completely recovered, but the plastic deformation cannot be recovered. The back plate 42 continues to move under the action of the forced displacement and finally returns to the initial loading position.
[0048] Table 3 shows the required displacement values for triaxial loading energy and loading force.
[0049] Table 3 Displacement values under triaxial loading
[0050] Lateral vertical direction Vertical Preload / mm 395 74 294 Standard value / mm 391 / 403 79 303
[0051] In Table 3, the value 391mm represents the force requirement achieved by lateral loading of 391mm; the value 403mm represents the energy requirement achieved by lateral loading of 403mm; the value 79mm represents the force requirement achieved by vertical loading of 79mm; and the value 303mm represents the force requirement achieved by longitudinal loading of 303mm.
[0052] S6. The results of the three-dimensional loading are analyzed to evaluate the safety performance of the cab. The anti-rollover performance requirements of the cab and the finite element calculation results are shown in Table 4.
[0053] Table 4 Anti-rollover performance
[0054] Lateral energy absorption / J Lateral load / N Vertical load / N Longitudinal load / N Target value 32665 135298 361962 104318 Simulation results 33569 136545 368850 108635
[0055] The comparison revealed that all indicators of the cab were higher than the target values, so the safety performance met the requirements, and no calculation non-convergence was found, indicating that the calculation results were good.
[0056] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A contact simulation analysis method for a cab rollover protection structure, characterized in that, Includes the following steps: Finite element modeling was performed on the cab to obtain the cab model, and the nonlinear mechanical properties of the materials of each structural component of the cab were input into the cab model; In the power display state, the cab model is subjected to unidirectional full displacement loading in different directions, including loading and unloading, in which the cab model is loaded in different directions in sequence. The loading includes: In the power display state, the contact plate of the new cab model is forcibly displaced in one direction. The contact plate continuously approaches the cab, causing the cab to deform until it contacts the top of the cab. The uninstallation includes: When the contact plate is subjected to a forced displacement that is equal to or opposite to the loading direction, the elastic deformation of the cab gradually recovers, the elastic deformation of the cab is completely recovered, but the plastic deformation cannot be recovered. The contact plate continues to move under the action of the forced displacement and finally returns to the initial loading position. Based on the results of unidirectional full displacement loading, estimate the displacement values required to achieve the standard requirements in different directions using the loading force and energy. A contact plate for loading in different directions is added to the top of the cab model to form a new cab model; Based on the estimated displacement values in different directions, the new cab model is loaded in different directions in sequence; The results of loading in different directions are analyzed to evaluate the safety performance of the cab.
2. The contact simulation analysis method for a cab rollover protection structure according to claim 1, characterized in that: The contact plate includes a mounting plate, a top plate, a back plate, and side plates. The top plate is located above the cab, the back plate is located behind the cab, and the side plates are located on both sides of the cab. The edges of the mounting plate, back plate, and side plates are connected to the edges of the top plate, and the mounting plate is inserted into the top of the cab.
3. The contact simulation analysis method for a cab rollover protection structure according to claim 2, characterized in that: The contact plate has a density ≤1×10 -9 t / mm 3 Elastic modulus ≥ 4 × 10 5 Rigid materials with a pressure of MPa.
4. The contact simulation analysis method for a cab rollover protection structure according to claim 2, characterized in that: The back panel and side panels are grooved, with the grooves of the back panel and side panels pointing towards the cab.
5. The contact simulation analysis method for a cab rollover protection structure according to claim 1, characterized in that: Different directions include vertical, lateral, and longitudinal.
6. The contact simulation analysis method for a cab rollover protection structure according to claim 5, characterized in that: The cab model was loaded sequentially in the lateral, vertical, and longitudinal directions.
7. The contact simulation analysis method for a cab rollover protection structure according to claim 1, characterized in that: In a zero-gravity state, the cab model was loaded in different directions in sequence.