塔带机输送臂转向工况动力学分析

由塔式起重机和皮带输送机组合而成的塔带机是大型混凝土浇注工程所需的重要设备,其混凝土输送臂的换向是通过塔机带动完成的,是一种很特殊的换向方式,文中对该工况进行了多体系统动力学分析.将输送臂、钢丝绳视为运动柔性体,运动方程采用一种新的有限元显式表达形式,与吊臂一起组装建立系统动力学方程,以三峡工地某进口大型塔带机为研究对象,对输送臂转向工况的可行性、初始状态对换向工作的影响、换向冲击等进行了分析研究.吊臂制动后,输送臂在摆动过程中实现换向,输送臂不同的初始位置对应不同的临界初始角速度,初始角速度必须大于该临界值,初始角速度越大冲击产生的振动越大,初始状态的选择有个最佳的范围,该文正确地揭示了塔带机转向工况的动态特性.

Dynamic analysis of tower belt in case of changing conveyer direction

A tower crane supported concrete conveyor belt system is an important piece of equipment for placing concrete.The conveyor belt changes direction with the help of the tower crane.A multi-body dynamic analysis was made of a large tower belt used at a construction site of the Three Gorges Dam in Hubei,China.Feasibility of this special operating mode,effect of the initial condition,and resultant shock were studied.Conveyers and steel wire were treated as moving flexible bodies,and a new explicit expression by finite element method(FEM) was developed.Motion equations of the conveyers,steel wire,and jib were assembled to form the system equation.The direction of conveyers could be changed during its swing motion after the jib was stopped.Analysis showed different critical initial slew velocities for different initial positions of the conveyer,and that the initial slew velocity must be greater than the critical value.Greater initial slew velocity caused greater vibration and a best range for initial condition was determined.