含可动机构的杆系结构非线性力法分析

推导了基于矩阵奇异值分解的小变形条件下杆系结构的力法分析（LFM）过程，并采用杆件内力修正的方法，提出了考虑大位移的几何非线性力法分析（NFM）方法思想和步骤。该方法有效地解决了结构中同时存在刚体位移、弹性位移的结构分析问题，适合计算机编程，结构的强度计算、机构分析和形态分析，讨论了力法与位移法的优缺点，给出的算例表明所提出的方法是正确的、有效的。

NONLINEAR FORCE METHOD ANALYSIS FOR SPACE TRUSS WITH MOBILE MECHANISMS

A linear force method (LFM) base on the singular value decomposition (SVD) is proposed. Moreover, the nonlinear force method (NFM) is described in details through modifying the bar force value. Solutions are obtained effectively from NFM for the structures with rigid-body displacements and elastic deformations. From a series of numerical examples, this proposed method proved to be accurate and efficient for stress computation, mechanisms analysis and form-finding application.