桁架结构几何非线性问题的力密度法

桁架结构大都具有较强的几何非线；浊，受荷载后易出现较大的脯变形。提出一种基于力密度的针对桁架结构几何大变形问题的解法；引入杆件单元的力密度矩阵，推导出相应非线性方程的Jacobi矩阵；与有限单元法集成求解的思想相同，采用力密度矩阵建立结构变形后整体的精确非线性平衡方程。研究结果表明：应用Newton-Raphson迭代法求解，采用适当的迭代收敛精度可得到较精确的桁架结构位移解。

Force density algorithm for truss structures with geometric nonlinearity

Truss structures always show strongly geometric nonlinearity and tend to be deformed with large geometric deformation under loads.This paper presents a new force density formulation for truss structures with geometric nonlinearity.Based on force density matrix,the corresponding Jacobi matrix can be derived.Similar to Finite Element Method,the global accurate nonlinear balance equation based on force density matrix,can be solved by the Newton-Raphson iteration method.Examples show that accurate solutions can...