基于梁理论的龙门起重机动力学研究

发布时间：2019-01-05 07:22

【摘要】：起重机在工作过程中的动力学响应问题是起重机动力学研究的一项重要课题。随着机械工程的迅速发展,龙门起重机的需求不断增长,其在工作过程中产生的振动问题成为一个不容忽视的问题。国内外关于龙门起重机动力学问题方面的研究虽然已经做了很多工作,但是结合梁理论进行起重机动力学方面的研究较少,在这些方面还有很多问题亟待进一步研究。本文以龙门起重机为研究对象,分别基于Euler-Bernoulli梁理论和Timoshenko粱理论,结合结构振动力学、数值分析方法及有限元法等相关理论,系统地研究了主梁-小车耦合振动系统以及门架-小车-吊重耦合振动系统的振动特性。同时,借助于动力学仿真软件,对起重机进行了动力学仿真分析。研究的主要内容包括： (1)基于Euler-Bernoulli梁理论,忽略梁的横向剪切变形,建立龙门起重机主梁-小车的耦合系统振动模型,并推导出系统的耦合振动微分方程,利用数值方法进行求解,并得出了主梁与小车耦合系统的固有频率随小车在主梁上的相对位置改变的变化规律。 (2)根据Lagrange方程建立了小车吊重系统的动力学方程,对影响吊重偏摆的因素进行了分析。根据龙门起重机实际工作情况建立了龙门起重机门架-小车-吊重系统的耦合振动模型。考虑梁的剪切变形和转动效应,基于Timoshenko梁理论建立耦合振动系统微分方程。通过有限元法得到龙门起重机结构所需的各阶模态,并将其代入系统的耦合振动方程,并运用数值方法得到耦合系统振动微分方程的数值解,并分析了耦合振动系统的振动特性。 (3)运用CAD软件SolidWorks建立龙门起重机的三维实体模型,并通过导入有限元分析软件ALGOR,对龙门起重机作了动力学仿真分析,得到了小车处于主梁不同的位置时整个结构的固有频率和振型,并对结果进行了分析。同时,将实体建模与梁单元建模的结果进行了对比分析。通过ALGOR非线性材料运动仿真分析,进行了龙门起重机的刚柔耦合运动仿真分析,得出了小车运动时主梁的响应。
[Abstract]:The dynamic response of crane in the working process is an important subject in the research of crane dynamics. With the rapid development of mechanical engineering, the demand of gantry crane is increasing, and the vibration of gantry crane has become a problem that can not be ignored. Although much work has been done on the dynamics of gantry cranes at home and abroad, there are few researches on crane dynamics based on beam theory, and there are still many problems to be further studied. This paper takes gantry crane as the research object, based on Euler-Bernoulli beam theory and Timoshenko beam theory, combined with structural vibration dynamics, numerical analysis method and finite element method and other related theories. The vibration characteristics of the coupling vibration system between the main beam and the trolley and the gantry-trolley-crane coupling vibration system are systematically studied in this paper. At the same time, with the help of dynamic simulation software, the dynamic simulation analysis of crane is carried out. The main contents are as follows: (1) based on the Euler-Bernoulli beam theory and ignoring the transverse shear deformation of the beam, the vibration model of the coupling system between the main girder and the trolley of the gantry crane is established, and the differential equation of the coupling vibration of the system is derived. The numerical method is used to solve the problem, and the variation of the natural frequency of the coupling system between the main beam and the trolley with the relative position of the vehicle on the main beam is obtained. (2) based on the Lagrange equation, the dynamic equations of the lifting system are established, and the factors affecting the lifting deflection are analyzed. The coupled vibration model of gantry crane gantry-trolley-crane system is established according to the actual working conditions of gantry crane. Considering the shear deformation and rotational effect of beam, the differential equation of coupled vibration system is established based on Timoshenko beam theory. The modes of gantry crane structure are obtained by finite element method, and the coupled vibration equation of the system is replaced by the finite element method. The numerical solution of the differential equation of vibration of the coupled system is obtained by using the numerical method. The vibration characteristics of the coupled vibration system are analyzed. (3) the three-dimensional solid model of gantry crane is established by using CAD software SolidWorks, and the dynamic simulation analysis of gantry crane is made by introducing the finite element analysis software ALGOR,. The natural frequencies and modes of the whole structure are obtained when the car is in different positions of the main beam, and the results are analyzed. At the same time, the results of solid modeling and beam element modeling are compared and analyzed. The rigid-flexible coupling motion of gantry crane is simulated by ALGOR nonlinear material motion simulation, and the response of the main beam is obtained when the trolley is moving.
【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】：TH213.5

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