履带起重机臂架的静动力学分析与仿真

发布时间：2018-06-01 02:53

本文选题：臂架 + 有限元分析　；参考：《东北大学》2011年硕士论文

【摘要】：臂架是履带起重机承受载荷的主要部件之一,臂架的静动态特性对履带起重机的安全性有着直接的影响。臂架不但组合方式多,而且载荷复杂,无论采用工程分析方法还是有限元法,对其受力特性进行全面的分析都是比较麻烦的事情。因此,有必要探讨反映臂架的力学特性且计算量小的分析方法,以及反应臂架真实工作状况的仿真方法。户外工作的起重机常受到风载荷的影响,对起重作业造成干扰,易引发事故。起重机是一种经常反复作业的机械,突然起吊和突然卸载的情况时有发生,这会对臂架产生瞬时冲击振动,虽然该瞬态响应作用的时间很短,但结构将在短时间内达到最大响应,对臂架的安全性有着不可忽视的影响。针对上述问题,本论文对某型号履带起重机18m臂架结构起吊额定起重量160t时的工况进行了静动力学分析及仿真。静力分析分有风和无风两种情况对突然起升和回转启动两种危险工况进行了强度校核,通过分析可知风载荷对回转启动工况影响较为严重,最大应力和最大位移值发生在突然起升工况。以振动理论为基础,对臂架进行了模态分析,得出了臂架的前几阶固有频率及相对应的振型,分析表明振源频率均不在臂架的固有频率范围内,臂架在正常工作时不会发生共振。根据起重机动力学,对突然起升工况和突然卸载工况进行了瞬态分析,可知突然起升工况对臂架的冲击较为严重。将突然起升工况的静力分析和动力分析结果进行对比可知,动力分析的最大应力值和位移值小于静力分析,可以确定静力分析时选取的动载系数偏大。由于在动力分析时将激振力函数简化为线性函数,与实际情况存在一定的差距,本文通过刚柔耦合仿真对突然起升工况进行了分析,进一步了解了该工况的动力学特性,为修正动载系数提供了参考。
[Abstract]:Boom is one of the main parts of crawler crane to bear load. The static and dynamic characteristics of boom have a direct effect on the safety of crawler crane. There are not only many combination modes, but also complicated loads. It is a troublesome matter to analyze the mechanical characteristics of the boom by using both the engineering analysis method and the finite element method. Therefore, it is necessary to discuss the analytical method which reflects the mechanical characteristics of the boom with less calculation and the simulation method of the real working condition of the reaction boom. Cranes working outdoors are often affected by wind load, which interfere with crane operation and cause accidents. A crane is a machine that often works repeatedly. Sudden lifting and unloading occur from time to time, which can produce transient shock vibration on the boom, although the transient response time is very short. However, the structure will reach the maximum response in a short time, which has an important effect on the safety of the boom. Aiming at the above problems, the static and dynamic analysis and simulation of a certain type crawler crane with 18m boom structure lifting rated lifting weight of 160 t are carried out in this paper. In the static analysis, wind and no wind are used to check the intensity of the two dangerous conditions of sudden rise and turn start. Through the analysis, it can be seen that the wind load has a serious effect on the rotary starting condition. Maximum stress and maximum displacement occur in sudden rise. Based on the vibration theory, the modal analysis of the boom is carried out, and the first natural frequencies of the boom and the corresponding vibration modes are obtained. The analysis shows that the vibration source frequencies are not within the natural frequency range of the boom. The boom does not resonate during normal operation. According to the crane dynamics, the transient analysis of the sudden lifting condition and the sudden unloading condition is carried out, which shows that the sudden lifting condition has a serious impact on the boom. The results of static analysis and dynamic analysis show that the maximum stress value and displacement value of dynamic analysis are smaller than that of static analysis, and the dynamic load coefficient selected in static analysis can be determined to be larger. Since the excitation force function is simplified to a linear function in dynamic analysis, there is a certain gap between the dynamic and the actual situation. In this paper, a rigid and flexible coupling simulation is used to analyze the sudden lifting condition, and the dynamic characteristics of the working condition are further understood. It provides a reference for modifying the dynamic load coefficient.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH213.7

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