钢桁架优化设计中稳定及收敛问题的有效解法

在超静定型钢桁架满应力优化设计中，压杆的稳定性，即：计算 迭代中压杆的稳定许用应力，提高迭代过程的收敛速度，是两个关键问题，迄今为止 尚未得到有效地解决，从而影响了满应力优化设计方法在桁架结构中的应用. 为解决上述两问题, 首先建立了两个拟合函数，建立了型钢截面积与惯性半径及压杆的稳定， 系数与柔度之间的函数关系，继而导出了压杆稳定许用应力的计算方法， 归纳出了加速收敛的有效措施------面积平均法. 算例证明了 本文方法的可靠性，供有关结构设计人员参考.

AN EFFICIENT SOLUTION METHOD FOR THE PROBLEM OF STABILITY AND CONVERGENCE IN OPTIMAL DESIGN OF SHAPE STEEL TRUSS

In a full-stress optimal design for statically indeterminate shape steel truss,it is important to calculate the allowable stress for stability of compressed rod in every step of calculation and to speed up convergence for applications.In this paper,on the basis of two functions,i.e.the relation between the section area of shape steel and the radius of inertia and the relation between the coefficient of stability of compressed rod and the slenderness ratio,computing method for the allowable stress for stability of compressed rod is derived,and an efficient method to speed up convergence,i.e.the area average method,is proposed by analyzing examples.