地震动加加速度反应谱的概念及特性研究  

STUDY ON CONCEPT AND CHARACTERISTICS OF SEISMIC JERK RESPONSE SPECTRA

作　　者：何浩祥[1] 闫维明[1] 陈彦江[1] 

机构地区：[1]北京工业大学工程抗震与结构诊治北京市重点实验室,北京100124

出　　处：《工程力学》2011年第11期124-129,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(50878010;50978009);北京市教委科技计划面上项目(JC004013201003)

摘　　要：加加速度是加速度关于时间的变化率,反映了结构受力变化情况。地震动加加速度及其反应谱的研究可以加强人们对地震动非平稳性的认识。阐述了加加速度的力学意义及研究价值,探讨了计算加加速度的动力学方法并对其优缺点进行了比较。建立了地震动下弹性及弹塑性加加速度反应谱的求解方法。根据场地类型、放大系数、延性系数及折减系数等影响因素对加加速度反应谱的特性进行了研究,并提出了冲击折减系数的概念。结果表明加加速度对中短周期的建筑结构作用较明显,适当提高延性将有效降低加加速度造成的冲击效应。冲击折减系数随着结构周期增大明显增大,加加速度对于长周期结构的影响一般可以忽略。Jerk is the time rate of acceleration, reflecting the variation of structural forces. The study on jerk andits response spectra can enhance the recognitions on the non-stationary of ground moUon, The mechanical meaning and research value of jerk is described. The calculating methods for jerk are discussed and their performance and disadvantages are compared. The solution method of elastic and inelastic jerk response spectra under ground motion is established. The characteristics of jerk response spectra are studied according to the influencing factors, such as a site condition, an amplification factor, a ductility factor and a reduction factor. The concept of an impact reduction factor is presented. The analysis results show that jerk influences the building structures with short or middle periods more obviously, and the impact responses can be reduced significantly when the structural ductility is enhanced. The impact reduction factor increases with the incensement of a structural natural period and the influence of jerk on long-period structure can be ignored.

关 键 词：加加速度 地震动 反应谱 折减系数 延性系数 

分 类 号：P315.31[天文地球—地震学] TU311.3[天文地球—固体地球物理学]