车辐式屋盖结构的一种索力识别方法的误差研究

RESEARCH ON ERROR OF A CABLE FORCE ESTIMATION METHOD FOR SPOKE STRUCTURAL ROOFS

基于一种由静力位移测量值识别车辐式结构索力的方法,该文评估了位移测量误差对于索力识别结果的影响,用数值计算及理论推导得到了二者的关系。索力识别误差是位移测量误差的单调函数。在位移值远大于测量误差时,该函数接近线性,否则有明显的非线性。在误差幅值相同的情况下,选择不同的加载及测量方案,索力识别的精度是不同的:单位荷载产生的节点位移越大,索力识别结果的误差就越小。对多种加载-测量方案进行了比选,归纳了制定索力识别方案时应遵循的原则:加载方案应使结构的几何刚度发挥主要作用。对车辐式结构而言,在荷载总量一定的情况下,在半跨或1/4跨布置荷载能获得较好的索力识别结果。

Based on a cable force estimation method with static displacement for spoke structural roofs, the influence of displacement measurement error on the cable force estimation result is studied with numerical and theoretic analysis. Force estimation error is a monotone function of displacement measurement error. When the displacement is much larger than the measurement error, the function is almost linear, otherwise apparently nonlinear. With the same amplitude of displacement measurement error, the accuracy of cable force estimation varies remarkably due to load-measurement schemes. The error of force estimation result is small if the nodal displacement with respect to unit load is large. Several load-measurement schemes are compared, and the principle on making load-measurement scheme is to make structural geometric stiffness take primary effect. For spoke structures, half-span and quarter-span loads will achieve good force estimation results if the amount of loads is limited.