设计简介
摘 要
汽车车架作为汽车总成重要的一部分，车辆受到来自道路和装载的各种复杂载荷最终都会传递给车架，并且汽车上许多重要总成都是以车架为载体，因而车架的强度和刚度在汽车总体设计中起了非常重要的作用。因此，车架结构性能的好坏关乎这整车设计的成败。若用传统经典力学方法计算，结果失真太大；而用试验法进行测试，成本高，周期长。为此本文采用了有限元分析技术，来实现车架结构设计合理化和轻量化的目的从而大大减少设计费用，缩短设计周期，同时提高设计工作的效率。因为，ANSYS在对实体模型分析上具有强大的功能，在结构静力学分析以及优化设计方面相比很多其他软件拥有十分明显的优越性。本文利用三维建模软件Pro/E和有限元分析软件ANSYS对某轻型载货汽车车架进行了Pro/E建模和ANSYS分析。
通过对Pro/E和ANSYS软件的的了解和学习，采用Pro/E实体建模，导入ANSYS进行网格划分，应力加载，求解得出经动态分析结果，得出结论，之后可根据需要对已设计的实体单元为基础的车架结构进行拓扑优化模型和简单的尺寸优化模型，以车架的纵梁截面尺寸为设计变量，以车架结构的总体积最下为优化目标，对车架纵梁截面尺寸进行优化并分析优化结果。通过对初步设计出的轻型车架结构的实体建模及有限元分析，得到一些对车架设计有所帮助的结论，为今后车架的设计工作提供一定的指导作用。
关键词：轻型货车车架；三维建模；载荷；有限元静力学分析；模态分析
ABSTRACT
Automobile frame, as an important part of the vehicle, the vehicle being loaded from the road and the complex will eventually be passed to the load frame, and the car is the frame number of important general in Chengdu as the carrier, and thus the strength and the framestiffness of the overall design of the car plays a very important role.Therefore, the performance is good or bad frame structure about the success of this vehicle design.If the traditional method of classical mechanics, the result is too large distortion; and tested using test method, high cost and long period.To this end this paper, the finite element analysis, design of the frame structure to achieve the purpose of rationalization and lightweight thus reducing design costs and shorten design cycles, while improving the efficiency of design work.Because, ANSYS solid model in the analysis of powerful features in the structure of static analysis and design optimization software, compared with many other obvious advantages.In this paper, three-dimensional modeling software Pro / E and the finite element analysis software ANSYS, a light truck chassis is a Pro / E modeling and ANSYS.
On Pro / E and ANSYS software, understanding and learning, the use of Pro / E solid modeling, meshing into ANSYS, the stress load, obtained by solving the dynamic analysis of the results, draw conclusions, and then as needed for. The solid element has been designed based on the topology optimization of frame structure model and the size of a simple optimization model to frame the longitudinal cross-section dimensions of design variables, the total volume of the frame structure to optimize the next goal, on the framelongitudinal section size optimization and analysis of optimization results.The preliminary design by a light frame structure of solid modeling and finite element analysis, get some help on the conclusions of the frame design, frame design for the future to provide some guidance.
Key words：Frame of track; Three-dimensional modeling; loads; Finite element static analysis; Modal analysis
汽车车架作为汽车总成重要的一部分，车辆受到来自道路和装载的各种复杂载荷最终都会传递给车架，并且汽车上许多重要总成都是以车架为载体，因而车架的强度和刚度在汽车总体设计中起了非常重要的作用。因此，车架结构性能的好坏关乎这整车设计的成败。若用传统经典力学方法计算，结果失真太大；而用试验法进行测试，成本高，周期长。为此本文采用了有限元分析技术，来实现车架结构设计合理化和轻量化的目的从而大大减少设计费用，缩短设计周期，同时提高设计工作的效率。因为，ANSYS在对实体模型分析上具有强大的功能，在结构静力学分析以及优化设计方面相比很多其他软件拥有十分明显的优越性。本文利用三维建模软件Pro/E和有限元分析软件ANSYS对某轻型载货汽车车架进行了Pro/E建模和ANSYS分析。
通过对Pro/E和ANSYS软件的的了解和学习，采用Pro/E实体建模，导入ANSYS进行网格划分，应力加载，求解得出经动态分析结果，得出结论，之后可根据需要对已设计的实体单元为基础的车架结构进行拓扑优化模型和简单的尺寸优化模型，以车架的纵梁截面尺寸为设计变量，以车架结构的总体积最下为优化目标，对车架纵梁截面尺寸进行优化并分析优化结果。通过对初步设计出的轻型车架结构的实体建模及有限元分析，得到一些对车架设计有所帮助的结论，为今后车架的设计工作提供一定的指导作用。
关键词：轻型货车车架；三维建模；载荷；有限元静力学分析；模态分析
ABSTRACT
Automobile frame, as an important part of the vehicle, the vehicle being loaded from the road and the complex will eventually be passed to the load frame, and the car is the frame number of important general in Chengdu as the carrier, and thus the strength and the framestiffness of the overall design of the car plays a very important role.Therefore, the performance is good or bad frame structure about the success of this vehicle design.If the traditional method of classical mechanics, the result is too large distortion; and tested using test method, high cost and long period.To this end this paper, the finite element analysis, design of the frame structure to achieve the purpose of rationalization and lightweight thus reducing design costs and shorten design cycles, while improving the efficiency of design work.Because, ANSYS solid model in the analysis of powerful features in the structure of static analysis and design optimization software, compared with many other obvious advantages.In this paper, three-dimensional modeling software Pro / E and the finite element analysis software ANSYS, a light truck chassis is a Pro / E modeling and ANSYS.
On Pro / E and ANSYS software, understanding and learning, the use of Pro / E solid modeling, meshing into ANSYS, the stress load, obtained by solving the dynamic analysis of the results, draw conclusions, and then as needed for. The solid element has been designed based on the topology optimization of frame structure model and the size of a simple optimization model to frame the longitudinal cross-section dimensions of design variables, the total volume of the frame structure to optimize the next goal, on the framelongitudinal section size optimization and analysis of optimization results.The preliminary design by a light frame structure of solid modeling and finite element analysis, get some help on the conclusions of the frame design, frame design for the future to provide some guidance.
Key words：Frame of track; Three-dimensional modeling; loads; Finite element static analysis; Modal analysis
目 录
摘要 I
Abstract II
第1章 绪论 1
1.1 研究目的和意义 1
1.2 车架国内外研究现状 2
1.3 主要设计内容 4
1.4 拟解决的主要问题 5
第2章 轻型货车的车架设计 6
2.1 车架的概述 6
2.1.1 车架的设计要求 6
2.1.2 车架的结构型式 6
2.1.3 纵梁、横梁及其联接 10
2.1.4 车架的制造工艺及材料 11
2.2 车架的结构设计 12
2.2.1 车架设计参考 12
2.2.2 车架参数的确定 13
2.2.3 车架的弯矩及弯曲应力计算 14
2.2.4 车架的挠度计算 16
2.3 本章小结 18
第3章 车架三维模型的建立 19
3.1 Pro/E软件介绍 19
3.2 三维模型的建立 20
3.3 本章小结 24
第4章 车架有限元分析 25
4.1 ANSYS的特点 25
4.2 ANSYS的基本组成和功能 26
4.3 Pro/E与ANSYS接口的创建 28
4.4 车架有限元的静力分析 30
4.4.1 三维实体模型的网格划分 30
4.4.2 施加约束条件 31
4.4.3 车架4种工况分析 32
4.5 车架有限元的模态分析 42
4.6 本章小结 48
结论 49
参考文献 50
致谢 51
附录 52
附录A 外文文献 52
附录B 外文文献翻译 58
附录C ANSYS分析程序命令流 63
附C1 车架4工况分析前准备程序 63
附C2 车架弯曲工况ANSYS分析程序 70
附C3 车架扭转工况ANSYS分析程序 75
附C4 车架急刹车工况ANSYS分析程序 79
附C5 车架转弯工况ANSYS分析程序 85
附C6 车架模态分析程序 90
