工程结构可靠度分析简介——荷载模型与结构抗力模型

一、概述施加在结构上集中力或分布力的集合或在结构中产生的外加变形或约束变形的原因,总称为结构上的作用。因此,用“作用”这一概念来取代并扩大“荷载”这一概念。施加在结构上集中力或分布力的集合是对结构的一种直接作用,例如结构的自重、人或物形成的重力荷载、风压力构成的风荷载、浪压力构成的波浪荷载等等都会使结构产生内力和变形。地震作用可使结构产生外加变形;温度变化会导致结构产生约束变形等,这些外加变形或约束变形同样会使内部产生应力和应变。

基于遗传退火算法的高层建筑结构抗震设计研究

在多种环境因素及材料自身性能退化的作用下,建筑的抗震能力会逐渐下降。针对这一问题,论文基于遗传退火算法,对高层建筑结构抗震展开设计研究。首先构建了建筑结构抗力模型,并在模型中引入时间参量,以在建筑预期使用年限内,模型最终输出的结果仍能够达到抗震设计需求为目标,采用遗传退火算法对高层建筑结构实施抗震设计,分别从材料本身和外界环境因素两个角度进行寻优。测试结果表明,基于遗传退火算法的高层建筑结构抗震设计方案能够确保建筑的稳定性,使建筑具有较高的抗震性能。

Lateral stiffness of steel plate shear walls

The steel plate shear wall system has been used in a number of buildings as an innovative lateral force resistant system.Openings often exist in the steel plate shear walls due to the various functional requirements of structures.These openings may negatively impact the lateral stiffness of steel plate shear walls.Therefore,an experimental research was instituted to investigate the seismic behavior of steel plate shear walls,with and without openings.The experimental results showed that steel plate shear walls have the satisfying seismic behavior,and,as expected,the strength and stiffness characteristics of the walls were reduced due to openings.Then a single-story wall panel FE model and an analytical deep beam model are developed in order to find the critical factors dominating the thickness reduction coefficient of wall panels with the opening.Furthermore,extensive parametric analysis is conducted to derive a simplified formula for the determination of the thickness reduction coefficient of wall panels with the opening for substituting solid wall panels with reduced thickness for actual wall panels with the opening.Finally,the design method for calculating the lateral stiffness is verified by some experimental programs and recommended for the routine practice of steel plate shear walls.