基于ABAQUS的VDLOAD子程序实现四轮小车移动

ABAQUS Power and Flexibility in Subroutine Developments: Case Study on a FourWheeled Vehicle's Path Modeling with the VDLOAD Subroutine

AB AQUS, widely recognized for its capabilities in Finite Element Analysis (FEA) and its extensive subroutines for enhancing the predictive accuracy and complexity of simulations, has attracted a large community of researchers and engineers particularly for its programmable capabilities. The key subroutine for defining spatially and temporally varying loads over an undefined number of nodes is `VDLOAD`. This function is pivotal for simulating dynamic events such as automotive motion and laser impact scenarios.

Overview of `VDLOAD` Subroutine


Description

The `VDLOAD` subroutine is an example of a readonly, fixed set of parameters alongside a writeonly variable, enabling the simulation of loading conditions over an undefined number of nodes (`nBlock`). It specifies the load at each node tailored to the analysis steps (`steptime`), total time (`totaltime`), coordinates (`curCoords`), and velocities (`velocity`) of the nodes. The load applied (`value`) can change with each node (`k`) for each analysis step.

Key Parameters and Functionality




`nBlock`: Number of nodes or blocks to apply the load.

`ndim`: Dimensionality of space, with options for one, two, or three dimensions ([X, Y, Z]).

`steptime`: Time step value indicating progression through each step of the simulation.

`totaltime`: Total time for the simulation from the start point of analysis.

`amplitude`: Perhaps an amplitude frequency parameter or a step for loading conditions, not clearly detailed in the provided code.

`curCoords`: Current node coordinates for position and orientation.

`velocity`: Velocity information, if applicable, to determine node movements.

`dirCos`: Direction cosines useful for orientation and direction adjustments in complex geometries.

`jltyp`: Likely specifying the type of load parameter or its application method.

`sname`: Identifier or name for the subroutine itself.

UserDefined `value(nblock)`

`value(nblock)` is the userdefined load value at each node, crucial for customized simulations.

Spatial and Temporal Analysis

The `VDLOAD` function iterates over all nodes (`km = 1 to nBlock`), defining the loading condition based on the current coordinates and parameters. For instance, in the example given, it models a fourwheeled vehicle's movement, where specific conditions determine if a wheel comes into contact with an area of high loading pressure (`pressure`).

Technical Detail: Modeling a FourWheeled Vehicle's Path

Required Parameters

`L1`: Spacing between front and rear axles.

`L2`: Spacing between wheels on the same axle.

`a`: Load application area side length defining the contact zone.

`speed`: Vehicle speed level factor influencing how the load progresses through simulations.

`t`: Current time step, a critical value that drives the loading and movement scenarios.

`distance`: Derived from `speed` and `steptime`, indicating the movement of the vehicle.

`xm`, `ym`: Initial distances of the vehicle's edges from the assumed modeling origin, typically the center.

`pressure`: Load level (3000 MPa typically for plastic strain monitoring).

Simulation Process and Output

Node Evaluation: The subroutine accesses each node's coordinates and timerelated parameters to determine loading conditions accordingly.

Pressure Application: Conditionals within the loop implement the physics of contact, not moving but applying force only dynamically where specific conditions in the vehicle's path are met.

Visualization: After computational processing and output, ABAQUS tools allow for the visualization of deformation, stress distribution, and strain across parts, supporting deep analysis of dynamic events.

Conclusion

The `VDLOAD` subroutine's implementation showcases the power of ABAQUS in custom simulation by enabling users to write logic (within the `[km = 1 to nBlock]` loop) that applies spacetime varying conditions based on specific parameters, like vehicle movement, load levels, and its interaction with a modeled surface. This intricate control over loading conditions facilitates the simulation of complex dynamics, such as the interaction of a fourwheeled vehicle with an external medium, critical in automotive and mechanical engineering studies.

武汉格发信息技术有限公司，格发许可优化管理系统可以帮你评估贵公司软件许可的真实需求，再低成本合规性管理软件许可,帮助贵司提高软件投资回报率，为软件采购、使用提供科学决策依据。支持的软件有: CAD,CAE,PDM,PLM,Catia,Ugnx, AutoCAD, Pro/E, Solidworks ,Hyperworks, Protel,CAXA,OpenWorks LandMark,MATLAB,Enovia,Winchill,TeamCenter,MathCAD,Ansys, Abaqus,ls-dyna, Fluent, MSC,Bentley,License,UG,ug,catia,Dassault Systèmes,AutoDesk,Altair,autocad,PTC,SolidWorks,Ansys,Siemens PLM Software,Paradigm,Mathworks,Borland,AVEVA,ESRI,hP,Solibri,Progman,Leica,Cadence,IBM,SIMULIA,Citrix,Sybase,Schlumberger,MSC Products...