精密定位平台柔性支撑杆屈曲分析

摘要

针对工程机械关键结构精密定位平台柔性支撑杆在结构设计上普遍存在屈曲失稳问题.首先基于瑞利-里兹能量变分法,建立计算精密定位平台柔性支撑杆屈曲临界载荷的数学模型并与有限元的Block Lanczos方法所求其前1阶屈曲载荷和屈曲模态进行对比,结果表明理论值与实验值偏差不大于0.26%,验证了基于瑞利-里兹能量变分法建模的准确性.最后对柔性支撑杆进行参数研究,发现长度比L/l与屈曲临界载荷呈反比例,直径比D/d小于1.5对屈曲临界载荷影响较大,倒角半径R与屈曲临界载荷正相关,为密定位平台柔性支撑杆的设计提供新的思路.%Precision positioning platform for engineering mechanical key structure is common in the structural design of flexible support bar buckling instability problems.First based on Rayleigh Ritz energy variation method, the calculation precision support through building the mathematical model of precision positioning platform flexible support bar buckling critical load and finite element Block Lanczos method for the 1 order before buckling load and buckling mode is compared, the results show that the theoretical value and experimental value deviation is not more than 0.26%, and verified the Rayleigh Ritz energy variation method based on the accuracy of the model.Finally the parameters study on flexible support bar, seeing an inverse proportion in length than L/l and the buckling critical load, than diameter D/d less than 1.5 influence on buckling critical load is bigger, chamfering radius R and the buckling critical load is related, for the design of the positioning platform flexible support bar provides new train of thought.