大跨度索杆张力结构的预应力分布计算

针对多自应力模态与机构位移模态索杆张力结构可行预应力分布求解的最复杂情形,为得到一种具有一定普遍意义的预应力优化求解策略,以该结构体系的一种新形式——大跨度环形平面空间索桁张力结构为基础,考虑其几何拓扑形式多样的特点,应用结构平衡矩阵理论与代数奇异值分解算法,通过对结构模态矩阵的分解变换及其组合运算,提出了一种可依据结构预应力分布的不同优化目标进行求解的新方法——目标选择优化法,使多自应力模态索杆张力结构体系的可行预应力分布求解工作得以便捷的实现。在此基础上,对大跨度索杆张力结构的预应力分布计算方法分三类进行了较为全面的总结;通过三种不同形式新型空间索杆张力结构的可行预应力分布求解算例,验证了上述计算方法的简捷与有效。

Calculation of prestress distribution for large-span cable-strut tensile structures

Based on the study of a new type of large-span structure,i.e.a spatial cable-truss tensile structure with an annular plane and complex geometric topology,a new method of prestress optimization using object-selection optimization was proposed.The main objective of the aforementioned method is to solve the complicated problem of feasible prestress distribution in cable-strut tensile structures with multi states of self-equilibrium stress and modes of mechanism displacement.In the proposed method,the modal matrix technique of decomposition and assembly operation,theory of structural equilibrium matrix and algebraic singular value decomposition method were employed.The method has a simple calculation format and can accomplish different objectives of structural prestress optimization.Three different ways in calculating the feasible prestress distribution in cable-strut tensile structures were summarized,and numerical results for three different types of structural systems were obtained to demonstrate the simplicity and validity of the proposed method.