主副一体式自卸车车架动力学分析及优化

发布时间：2018-02-21 03:45

本文关键词： 自卸车主副一体式车架动力学路面激励优化分析　出处：《太原理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：车架是自卸车的主要承载基体。在自卸车行驶过程中,车架要承受路面和动力传动装置等的激励,当车架的固有频率与外部其他因素产生的激励频率传递至车架发生耦合时,车架就会发生共振,这不仅会影响车架使用性能,甚至会引起结构和零部件的破坏和疲劳失效;车架外部激励是车架动态特性分析的基本输入,因此如何经济、方便、准确地获得外部激励就成为车架动态特性分析的基本任务;此外,车架作为基础部件,其结构尺寸是否合理在很大程度上影响整车的重心和动态特性等性能参数。因此,本文以DT002主副一体式自卸车车架为研究对象,在对车架进行模态分析的基础上,对整车数值动力学模型、多体动力学模型和实车试验测得的车架动态载荷历程进行了对比,并以车架一阶模态和车架重量为目标,对其进行了尺寸优化设计,进一步实现了车架的低重心、轻量化设计。为了分析DT002车架的动态特性,本文首先利用六分力测量仪采集了实际路面载荷,经过分析处理得到了路面载荷的频域响应谱,由结果可知路面激励产生的车架动态响应频率大多在5Hz以下。其次建立了车架的有限元模型,对车架进行了计算模态和试验模态对比分析,获取其前十阶模态特性,分析表明,除了二阶与十阶外,各阶计算模态误差均小于5%,其低阶模态表现良好,避开了路面激励频率和发动机激励频率,验证了车架有限元模型的合理性;然后,为了得到在典型路面行驶状态下车架的路面激励,分别建立了整车动力学数学模型和多体动力学数字模型,进行了整车场地及道路试验,对模型的仿真结果进行了对比分析,为车架的动态特性分析提供了基本的输入;在上述分析的基础上,对整车多体动力学数字模型在C、D级典型路面工况下的运动进行仿真分析,得到车架的动态应力特性曲线,找出了车架最大应力点位置;最后,在保持车架原有结构形态的基础上,考虑到车架结构件板厚对其低阶模态频率和整车轻量化的影响,以板厚为设计变量,以整车质量和一阶模态频率为目标,对车架主要部件进行了灵敏度分析,以确定各部件板厚对车架整体性能的影响大小,而且对优化后车架的静态特性和模态进行了校核。本文较为系统地对DT002一体式专用自卸车车架动态特性进行了分析研究,为车架的下一步升级改进、优化设计提供了基础数据,另一方面也为企业储备了DT002车架的相关技术数据,为今后整车的量产提供了技术参考。
[Abstract]:The frame is the main bearing base of the dump truck. In the driving process of the dump truck, the frame should bear the excitation of the road surface and the power transmission device, when the natural frequency of the frame and the excitation frequency generated by other external factors are transferred to the frame, There will be resonance in the frame, which will not only affect the performance of the frame, but also cause damage and fatigue failure of the structure and parts, the external excitation of the frame is the basic input of the dynamic characteristic analysis of the frame, so how to be economical and convenient, Accurate external excitation is the basic task of frame dynamic characteristic analysis. In addition, whether the structure size of frame is reasonable or not has great influence on the performance parameters such as the center of gravity and dynamic characteristics of the whole vehicle. In this paper, the frame of DT002 master and auxiliary dump truck is taken as the research object. On the basis of modal analysis of the frame, the dynamic load history of the whole vehicle, the multi-body dynamic model and the real vehicle test are compared. Taking the first-order mode and the weight of the frame as the target, the dimension optimization design of the frame is carried out, and the low center of gravity and lightweight design of the frame are further realized. In order to analyze the dynamic characteristics of the DT002 frame, In this paper, the actual road load is collected by using the six-component force measuring instrument, and the frequency response spectrum of the pavement load is obtained by analyzing and processing. The results show that the dynamic response frequency of the frame generated by the road excitation is below 5 Hz. Secondly, the finite element model of the frame is established, and the calculation mode and the test mode of the frame are compared and the first ten modal characteristics are obtained. Except for the second order and the tenth order, the calculation modal error of each order is less than 5, and the low order modal performance is good, which avoids the road surface excitation frequency and engine excitation frequency, and verifies the rationality of the finite element model of the frame. In order to obtain the road excitation of the frame under the typical road condition, the mathematical model of vehicle dynamics and the digital model of multi-body dynamics are established, and the vehicle field and road tests are carried out, and the simulation results of the model are compared and analyzed. On the basis of the above analysis, the dynamic stress characteristic curve of the frame is obtained by simulating and analyzing the motion of the multi-body dynamics digital model of the whole vehicle under the typical road condition. The position of the maximum stress point of the frame is found. Finally, on the basis of maintaining the original structure form of the frame, considering the influence of the plate thickness of the frame structure on its low-order modal frequency and the whole vehicle's lightweight, the thickness of the frame is taken as the design variable. Aiming at the whole vehicle mass and the first order modal frequency, the sensitivity analysis of the main parts of the frame is carried out to determine the influence of the plate thickness of each component on the overall performance of the frame. Moreover, the static characteristics and modal of the optimized frame are checked. The dynamic characteristics of the frame of the DT002 integrated dump truck are analyzed and studied systematically in this paper, which provides the basic data for the further upgrading and improvement of the frame and the optimization design. On the other hand, it also reserves the technical data of DT002 frame for the enterprise, and provides the technical reference for the mass production of the whole vehicle in the future.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.4

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