剪切型支撑框架的假想荷载法  

Notional load approach for shear-type braced frames

作　　者：童根树[1] 郭峻[1] 

机构地区：[1]浙江大学土木工程学系,浙江杭州310058

出　　处：《浙江大学学报（工学版）》2011年第12期2142-2149,共8页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(50578140)

摘　　要：为了在钢结构设计中避免确定框架柱的计算长度的复杂性,提出一种应用于剪切型支撑框架的假想荷载法,将假想荷载作用于框架楼层,与其他荷载组合进行二阶弹性分析,框架柱即可取层高为计算长度进行设计.推导了有水平力和无水平力作用时的假想水平力,发现水平力的作用不影响假想水平力的大小.采用几何和材料非线性分析方法,考虑构件初始弯曲、结构初始侧移和残余应力,研究了多种几何条件和荷载条件下的支撑框架,提出假想荷载近似计算公式,并与有限元结果进行对比.通过实际应用算例分析,验证了该简化公式能够应用于支撑框架的设计.A notional load approach used in braced frames was proposed to avoid the complexity in determining the effective length of columns during the design of steel structure. Notional loads were applied on the storey levels, and second order elastic analysis was conducted together with other loads. Columns were designed based on their system lengths. A formula was derived for the notional loads in cases of with and without horizontal load. Results showed that the notional load was independent of the horizontal load. A series of braced frames under different geometric and load conditions were analyzed by geometric and material nonlinear analysis （FEA） considering member initial bow, initial sway imperfection and residual stress. An approximate formula for the notional load was proposed and compared with the FEA results. The accuracy of the formula in practical application was verified through analysis of practical examples.

关 键 词：假想荷载 支撑框架 屈曲 计算长度 

分 类 号：TU323.5[建筑科学—结构工程]