动臂式塔机变截面吊臂的整体稳定性分析

Global stability analysis of the tapered luffing jib of tower crane

分析了由变截面段和等截面段组成的动臂式塔机吊臂平面内和平面外的整体稳定性.从多节阶梯柱的挠度微分方程出发,应用传递矩阵法,得到了阶梯柱模型整体稳定性欧拉临界力求解控制方程的表达式.使用多节阶梯柱模型模拟变截面柱,将由变截面段和等截面段组成的非等截面混合结构统一成多节阶梯柱模型,分析其整体稳定性.与几个经典算例和ANSYS计算结果比较表明,使该方法求解欧拉临界力的计算精度高.推荐将变截面柱分为6节各节长度相等的非等截面阶梯柱,欧拉临界力计算误差小于0.5%.

The in-plane and out-of-plane global stability of tower crane＇s tapered luffing jib was analyzed, which consists of tapered and uniform segments. From the governing differential equation for buckling of a multi-step column, the formula for solving the exact Euler critical force of global stability was obtained with the transfer matrix method. The tapered column was simulated by multi-step columns, and then the non-uniform structure with tapered and uniform segments was generalized into multi-step columns for buckling analysis. The results in the present paper are compared with some classical and ANSYS results. It shows that the proposed method provides higher computation accuracy. When using the multi-step column of 6 sections with the same length to simulate the tapered column, the error of Euler critical force is less than 0.5%.