某轻卡发动机悬置系统的设计_毕业论文.doc

摘要 发动机动力总成悬置系统是发动机应用工程重要部分，它的好坏直接影响着汽车的NVH性能，进而影响该车的市场份额。本论文主要阐述了动力总成悬置系统设计的基本理论，对悬置系统的各项参数的收集作了简单介绍，并利用MATLAB完成了悬置系统的初步设计计算，得到悬置系统的6阶固有频率在6个自由度方向的解耦率未达到要求，悬置系统需要进行参数优化。在本论文动力总成悬置系统优化设计中，其优化设计目标是6个自由度方向的解耦率达到一定水平，设计变量是前后悬置三个方向的刚度值，约束条件是6个固有频率的范围，优化得到的结果在固有频率分配和解耦率方面都有了明显的改善。最后对悬置系统其中的一个托架基于hypermesh软件进行了三种工况下的强度校核和约束模态第一阶频率的校核，校核结果均满足设计要求。 关键词：悬置系统；设计计算；MATLAB；优化；托架；CAE Abstract The engine mounting system is an important part of the engine application engineering, which directly affects the NVH performance of the vehicle and the market share of the vehicle. This paper mainly expounds the powertrain mounting system design of the basic theory, and briefly introduced collection of suspension system parameters. Then it has completed the preliminary design of the suspension system by using the MATLAB, the result is that six order natural frequency of the mounting system and each order modal in the rirection of six degree of decoupling ratedoes not meet the requirements and the mounting system parameters need to be optimized. In the power assembly mounting system optimization design, the design goal of this paper is the six degree of freedom decoupling rate reached a certain level, the design variables are three direction stiffness values of front and rear suspension and constraint conditions is six order natural frequency constraints.The optimized results in frequency assignment and the decoupling rate are significantly improved. Finally, the intensity in three cases and the first order frequency of a bracket of the suspension system is checked based on Hypermesh. The checked results meet the design requirements. Keywords: mounting system; Design calculation; MATLAB; optimization; bracket; CAE  目录 第一章 概论 1 1.1 概述 1 1.2 发动机悬置系统研究概况 1 1.2.1 悬置元件的研究进程 1 1.2.2 国内外悬置系统优化理论的研究概况 3 1.3 课题的研究意义和内容 6 第二章 悬置系统设计理论 7 2.1 悬置系统的隔振机理分析 7 2.1.1 发动机自身的激励分析 7 2.1.2 发动机隔振原理 8 2.2 动力总成悬置系统的动力模型的建立 11 2.2.1 动力总成悬置系统力学模型的建立 12 2.2.2 动力总成悬置系统数学模型的建立 13 2.2.3 动力总成悬置系统振动耦合特性分析 14 2.2.4 刚度矩阵