起重机起升机构事故状态下制动动态特性分析

发布时间：2018-04-13 05:32

本文选题：起升机构 + 制动特性　；参考：《武汉理工大学》2012年硕士论文

【摘要】：近年来因起重机零件失效导致货物失落或臂架坠落事故时有发生,在事故状态下制动,由于制动时间较短,机械状态变化激烈,机械系统将会产生强烈的冲击和振动,由此可能对结构造成破坏性的影响,目前对正常工作下的制动过程研究较为成熟,但在事故状态下的制动特性的研究还相对较少,故在起重机事故状态下,对制动过程的动态特性分析是十分必要的。本文以MQ4599门座起重机起升机构为研究对象,结合MATLAB数值仿真方法和ANSYS有限元分析方法,研究其在事故状态下制动时的动态特性。重点讨论起重机起升机构发生事故时,其制动过程的时间、行程、动载荷,确定机械在制动时的弹性振动规律,提取制动时臂架系统中具有代表性部位的位移随时间变化的历程,从位移响应求得各元件的应力或应变。论文的主要工作包括以下几个方面： (1)以起升机构传动系统为研究对象,分析在事故状态下起升传动系统的制动过程,计算不同事故状态下制动过程的时间,行程及钢丝绳张力。 (2)对实际系统进行合理的假设和简化,运用少自由度模型法,建立了为三质量三自由度的起升系统动力学模型。将制动过程分为两个阶段,详细分析事故状态下制动系统的振动规律,并通过MATLAB求解运动微分方程,选取合适的控制条件,求出各阶段臂架及货物位移及速度响应曲线,分析影响系统振动的因素。 (3)在不同的事故条件下,制动过程中的制动时间和行程不同,起重机系统受的动态激励也不同,运用ANSYS中分析并获得臂架系统在不同事故状态下的瞬态动力响应,包括动应力和典型节点的动应力时间历程曲线,分析事故状态下制动对结构产生的影响。
[Abstract]:In recent years, due to the failure of parts of the crane, the loss of goods or the fall of the boom has occurred from time to time. Because of the shorter braking time and the drastic change of the mechanical state, the mechanical system will produce strong shock and vibration.This may have a destructive effect on the structure. At present, the research on the braking process under normal working conditions is more mature, but the study of braking characteristics in the accident state is relatively less, so in the crane accident state,It is necessary to analyze the dynamic characteristics of braking process.In this paper, the lifting mechanism of MQ4599 gantry crane is taken as the research object, and the dynamic characteristics of the hoisting mechanism under the condition of accident are studied by combining the MATLAB numerical simulation method and the ANSYS finite element analysis method.The braking time, stroke and dynamic load of crane hoisting mechanism are discussed in detail, and the elastic vibration law of machinery during braking is determined.The course of displacement variation with time in representative parts of the boom system during braking is extracted and the stress or strain of each component is obtained from the displacement response.The main work of the thesis includes the following aspects:In this paper, the braking process of hoisting transmission system under accident is analyzed, and the time, stroke and wire rope tension of braking process under different accident conditions are calculated.2) based on the reasonable assumption and simplification of the actual system, the dynamic model of the lifting system with three masses and three degrees of freedom is established by using the model method of less degrees of freedom.The braking process is divided into two stages. The vibration law of the braking system under the condition of accident is analyzed in detail. The differential equation of motion is solved by MATLAB, and the appropriate control conditions are selected, and the displacement and velocity response curves of the boom and cargo in each stage are obtained.The factors affecting the vibration of the system are analyzed.3) under different accident conditions, the braking time and stroke in braking process are different, and the dynamic excitation of crane system is also different. The transient dynamic response of boom system under different accident conditions is analyzed and obtained by ANSYS.The dynamic stress and the dynamic stress time history curve of typical joints are included to analyze the influence of braking on the structure under the condition of accident.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.4

【引证文献】