文档介绍：Classified Index: University Code: 10213 :629 Security: Open
Dissertation for the Master’s Degree in Engineering
FINITE ELEMENT ANALYSIS AND LIGHTWEIGHT DESIGN OF THE PASSENGER CAR BIW
Candidate:
Yang Jialin
Supervisor:
. Luo Lijun
Academic Degree Applied for:
Master of Engineering
Speciality:
Vehicle Engineering
Affiliation:
College of Automobile Engineering
Date of Defence:
June, 2013
Degree-Conferring-Institution:
Harbin Institute of Technology
摘 要
节能性、安全性和环保性已经成为汽车技术发展的三大主题,汽车轻量化技术在保证汽车碰撞安全性、车身刚度等性能的同时,减轻汽车重量,进而提高汽车操控性和动力性,减少燃油消耗和尾气排放,达到节能环保的目标,因此汽车轻量化技术已经成为汽车领域内的重要课题,有着广阔的发展前景。本文对某乘用车白车身常见工况下的刚度、模态频率以及正面、侧面碰撞性能进行有限元分析,并针对白车身刚度、模态频率和碰撞安全性能分别进行结构改进及轻量化设计。
对白车身典型构件进行简化,得出白车身简化构件模型。对不同材料下的白车身简化梁件、板件静态性能和不同材料的碰撞冲击特性进行研究,得出局部性能下不同材料之间的关系,为白车身零部件进行材料替换提供依据和参考。
建立乘用车白车身静态性能和振动特性的仿真模型,对白车身弯曲刚度、扭转刚度、模态频率以及相应的强度进行分析,采用敏感度分析的方法选出进一步优化的零部件,进行材料替换和尺寸优化,在保证白车身静态性能和振动特性的同时,实现白车身的减重设计。
建立侧面碰撞工况下的有限元模型,对原车方案的侧面碰撞性能进行分析, 并对白车身结构性能轻量化方案进行验证分析。在轻量化方案的基础上对白车身侧面结构进行改进,采用拼焊板的方法对侧围板、B 柱、门槛梁等进行轻量化设计,在侧面结构减重的同时,提升侧面耐撞性。
建立正面碰撞工况下的乘用车仿真模型,对乘用车原车方案和结构轻量化方案正面碰撞性能进行分析,在此基础上改进乘用车前部结构,对前纵梁进行拼焊板设计,提升乘用车正面碰撞性能。
关键词:白车身;轻量化;有限元;耐撞性
Abstract
Automotive energy economy, safety and environment protection are three subjects of automotive development in the future. As well as reducing weight, improving handling and dynamics performance, achieving the target of energy conservation and environment protection, auto lightweight technology is to guarantee the crashworthiness, body stiffness and other properties. So auto lightweight technology has e a key project in automobile industries with broad prospect for development. This paper carries out finite element analyses on the body-in-white (BIW) of a passenger car for stiffness, vibration, strength and the frontal and side crashworthiness. In the mean time, structure improvement and lightweight design respectively for stiffness, vibration and crashworthiness are conducted.
Simplified models are obtained by simplifyi