基于柔度法的一次超静定刚架加载全过程分析

Whole process analysis of loading on statically indeterminate frame with one redundant based on flexibility method

为了研究超静定结构的弹塑性性能,用柔度法的基本原理,对一次超静定刚架在集中荷载作用下的加载全过程进行了弹塑性分析.分析结果表明,受力变形过程可分为3个阶段:弹性阶段;固定端处截面附近产生塑性变形到形成塑性铰阶段;固定端处截面附近弹塑性区卸载到刚结点处截面形成塑性流动阶段.给出了塑性铰处的相对转角及其引起的位移的计算方法,推导了加载各阶段的荷载、弯矩和位移计算公式.

For research of the elastoplastie performance of the statically indeterminate structure, the whole elastoplastie loading and deformation process of the statically indeterminate frame with one redundant under concentrated loads was analyzed by use of the flexibility method. The result shows that the deformation process can be divided into three stages： the stage of elastic deformation of the whole structure, the stage of plastic deformation occurring in the region dose to fixed end till the formation of plastic hinge, and the stage of plastic deformation occurring in the region near the rigid joint till the formation of plastic flow state. Then, the calculation methods for relative rotational angle at the plastic hinge as well as its induced displacement were obtained, and the formulas for load, bending moment, and displacement at different loading stages were derived.