山地掉层框架结构振型分解法合理振型数的研究  

Reasonable Mode Number Required in Mode Decomposition Method of Step-Terrace Frame Structure

作　　者：吴茜玲 李英民[1,2] 唐洋洋 WU Xiling;LI Yingmin;TANG Yangyang(School of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area.Chongqing University,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《结构工程师》2020年第5期81-88,共8页Structural Engineers

基　　金：国家自然科学基金项目(51638002);国家自然科学基金项目(51878101)。

摘　　要：高阶振型对山地掉层结构的某些部位有不可忽略的影响。以振型分解法为基础,通过两种控制方法:振型质量参与系数法、振型位移法,两种控制精度:90%、95%,对一山地掉层框架结构进行振型截断,分析结构响应的差异性,并通过改变该结构布置形式,探讨振型截断的影响规律。结果表明,振型分解法对山地掉层框架结构是适用的。振型截断的误差主要体现在掉层部位的中上层和上部结构顶层。沿顺坡向,掉层部位是受控制精度影响最大的楼层。对掉层层数不同的结构,掉层数越少,两种控制方法不同控制精度下的差异越明显;对掉层跨数及上部结构层数不同的结构,两种控制方法的规律相似;沿横坡向,上部结构顶层是受控制精度影响最大的楼层,且两种控制方法有差异,在掉层层数不同时体现最明显。High-order modes have a non-negligible effect on some parts of step-terrace structure.Based on the mode decomposition method,the modes of a step-terrace frame structure is truncated to analyze the difference of structural response by adopting two control methods:modal participa-ting mass ratio method and mode displacement method,and two kinds of control precisions:90% and 95%.Furthermore,a law of influence of mode truncation is explored by changing the structure arrangement. The result shows that the mode decomposition method is applicable for the step terrace frame structure.The error of mode truncation is mainly reflected in the middle and upper floor of drop floor and the top floor of structure.Along the slope,the drop floor is the floor most affected by the precision.The less the number of drop floors,the more obvious the difference between the two control methods when the precision is increased.For the drop floor span model and the upper floor model,two methods are similar.Along the cross-slope direction,the top floor of the structure is the floor most affected by the precision.And the two control methods are different,which is more obvious when the number of layers is different.

关 键 词：山地掉层框架结构 振型截断 振型质量参与系数法 振型位移法 

分 类 号：TU352.1[建筑科学—结构工程]