Simultaneous ultimate load and deformation analysis of strain softening frames under combined stresses
Simultaneous ultimate load and deformation analysis of strain softening frames under combined stresses
复制标题
复合应力下应变软化框架的极限载荷与变形同步分析
DOI：
10.1016/j.engstruct.2007.05.014
复制
发表时间：
2008
影响因子：
5.5
通讯作者：
F. Tin
中科院分区：
文献类型：
--
作者：
S. Tangaramvong;F. Tin
本文提出了一种在一个步骤中进行弹塑性分析的方法，以同时获得应变软化结构的极限荷载和相应的变形。在分段线性化软化屈服条件下，还考虑了弯矩和轴力联合作用的影响。然而，一个单调加载过程中假设一个小位移框架。我们提出了一个数学规划的方法来解决这个问题。特别是，制定导致一个具有挑战性的类的一个所谓的“数学规划与平衡约束”（MPEC）的实例。提出了各种基于非线性规划的算法来求解MPEC。数值例子来说明所描述的分析，也突出本构局部软化不稳定性和轴向力的框架的整体结构行为的影响。
This paper presents a method for carrying out, in a single step, an elastoplastic analysis to obtain simultaneously both the ultimate load and corresponding deformation of a strain softening structure. The effect of combined bending moment and axial force is also accounted for in the piecewise linearized softening yield condition. However, a monotonic loading process is assumed within a small displacement framework. We propose a mathematical programming approach to tackle this problem. In particular, the formulation leads to an instance of the challenging class of a so-called “mathematical program with equilibrium constraints” (MPEC). Various nonlinear programming based algorithms are proposed to solve the MPEC. Numerical examples are provided to illustrate the described analysis and also to highlight the effects of constitutive local softening instability and of axial forces on the overall structural behavior of the frames.