摘 要

随着时代的发展，汽车已经成为了我们日常生活中重要的一部分。也正是因为如此，汽车碰撞也会成为不可避免的一件事。所以减小汽车碰撞造成的损害而进行汽车的结构优化也成为了重要的研究课题.。现在针对某企业正在进行开发的特种车底盘，进行设计、分析和优化，由于要求底盘能够承受住车辆的碰撞碾压，因此需要保证所设计的底盘的结构有着足够强度和刚度。

本文主要通过对特种车车底盘进行有限元分析，通过仿真软件完成底盘车碰撞性能及其他各项性能等参数的分析，基于分析结果进行结构优化，以改善底盘车碰撞性能，降低零部件失效风险。

首先建立底盘的三维模型，通过研究确定该底盘结构为框架结构，在框架为主体的基础上，通过角钢和螺栓对盖板、底盘、裙边和四角等部位进行连接。

其次建立底盘的有限元模型，并对底盘进行了几何清理、网格划分，定义材料属性等，之后在有限元模型的基础上进行模态分析、静力学分析，验证了底盘结构的合理性。

最后进行车辆碰撞过程和动态碾压过程的有限元仿真，通过对假车与底盘碰撞仿真结果分析，从假车模型对底盘不同方向上的碾压来验证底盘结构的安全性。之后通过对比试验发现，对底盘的盖板加厚都能够有效地起到优化作用，可以使底盘结构更加不易产生形变。

关键词：特种车底盘，有限元分析，碰撞碾压，优化设计

Abstract

With the development of the times, automobile has become an important part of our daily life. Because of this, car collision will become an inevitable thing. Therefore, it has become an important research topic to optimize the structure of the vehicle in order to reduce the damage caused by the collision. At present, the design, analysis and optimization are carried out for the chassis of a special vehicle which is being developed by an enterprise. Because the chassis is required to withstand the impact and rolling of the vehicle, it is necessary to ensure that the chassis structure has sufficient strength and rigidity.

This paper designs, analyzes and optimizes the chassis of special vehicle which is being developed for an enterprise. This paper mainly through the finite element analysis of the chassis car, through the simulation software to complete the analysis of the chassis car crash performance and other performance parameters, based on the analysis results to optimize the structure, in order to improve the chassis car crash performance, reduce the risk of parts failure.

Firstly, the three-dimensional model of the chassis is established, and the chassis structure is determined as a frame structure through research. On the basis of the frame as the main body, the cover plate, chassis, skirt and four corners are connected by angle steel and bolts.

Secondly, the finite element model of the chassis is established, and the chassis is cleaned up, meshed, and material properties are defined. Then, based on the finite element model, modal analysis and static analysis are carried out to verify the rationality of the chassis structure.

Finally, the finite element simulation of vehicle collision process and dynamic rolling process is carried out. Through the analysis of the simulation results of the collision between the fake vehicle and the chassis, the safety of the chassis structure is verified by rolling the chassis in different directions from the fake vehicle model. After that, through the comparative test, it is found that the thickening of the cover plate of the chassis can effectively play an optimization role, which can make the chassis structure more difficult to deform.

Keywords: special vehicle chassis, finite element analysis, collision rolling, optimization design

目录

第1章 绪论 1

1.1 研究背景及意义 1

1.2 国内外发展现状 1

1.2.1 国内研究现状 1

1.2.2国外研究现状 3

1.3 本文主要研究内容 4

第2章 特种车底盘三维模型的建立 5

2.1 底盘整体结构设计方案 5

2.2 底盘零部件设计 6

2.3 本章小结 10

第3章 底盘有限元模型的建立与仿真分析 11

3.1 有限元方法的理论基础 11

3.2 底盘有限元模型的构建 12

3.3 底盘模态分析 13

3.4 底盘静力学分析 15

3.5 本章小结 17

第4章 底盘动态碾压仿真 18

4.1 显式非线性算法理论基础 18

4.2 底盘动态碾压有限元模型的建立 19

4.3 底盘动态碾压求解分析 20

4.4 结构耐撞性改进方案 23

4.5本章小结 24

第5章 结论及展望 25

5.1 结论 25

5.2 展望 25

致谢 26

参考文献 27

第1章 绪论

1.1 研究背景及意义

随着时代的发展，汽车已经成为了我们日常生活中重要的一部分。也正是因为如此，汽车碰撞也会成为不可避免的一件事。但由于汽车碰撞用真实的汽车进行试验所需的经费和产生的浪费会很巨大，所以通过计算机软件来进行汽车碰撞仿真以便研究汽车碰撞的过程便成为了不可或缺的研究方式，与此同时，针对减小汽车碰撞造成的损害而进行汽车的结构优化也成为了重要的研究课题。汽车碰撞仿真及其结构优化是研究汽车不可或缺的重要一环。

汽车碰撞通常大多进行的都是汽车正面碰撞和汽车侧面碰撞碰撞，当然也有研究前纵梁及其他等等。早期试验都是靠实车碰撞或者模拟实车撞车试验来完成的。随着科技的发展，计算机的不断增强，碰撞仿真软件模拟出的数据逐渐更加接近真实碰撞，大部分试验都由计算机仿真替代了真实碰撞。现在大部分碰撞仿真运用的软件都是RADIOSS和LS-DANA，通过这些软件进行碰撞仿真从而收集该过程中的各类数据，最常需要的便是应力和变形位移等数据，通过这些数据可以进行分析研究对象是否满足研究所需从而达成实验目的。