化学爆炸等效单自由度结构体系抗力动力系数分析  

Dynamical coefficient of resistance of an equivalent SDOF structural system under chemical explosion load

作　　者：耿少波[1,2] 葛培杰 刘亚玲[1] 李洪 GENG Shaobo;GE Peijie;LIU Yaling;LI Hong(Department of Civil Engineering,North University of China,Taiyuan 030051,China;Bridge Structure Safety Technology National Engineering Laboratory,Chang’an University,Xi’an 710064,China;Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]中北大学土木工程学科部,太原030051 [2]长安大学桥梁结构安全技术国家工程实验室,西安710064 [3]大连理工大学水利工程学院,大连116024

出　　处：《振动与冲击》2019年第6期166-171,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金(51408558);桥梁结构安全技术国家工程实验室开放基金(2014G1502002)

摘　　要：由化学爆炸荷载特点,选取了线性等效荷载与多项式曲线拟合衰减荷载两种函数类型,从等效单自由度微分方程入手,对比了线性等效荷载的等效作用时长、多项式曲线拟合衰减荷载的作用时长与结构进入塑性响应时间之间大小关系,推导出了弹塑性阶段抗力动力系数表达式。通过算例表明多项式曲线拟合衰减荷载可应用范围大于线性等效荷载,且可反映化学爆炸荷载形状调整参数对动力系数的影响程度,线性等效荷载求解简单应用简便,在延性比较小时其动力系数稍偏大对设计有利,在延性比较大且结构刚度较大时动力系数偏小且低于比例可达19%,对设计不利。Considering the chemical explosion characteristics,two types of load functions,the linear equivalent load and polynomial curve fitting attenuation load,were selected to solve an equivalent SDOF differential equation. The equivalent load duration based on the linear equivalent load and the load duration based on the polynomial curve fitting attenuation load were compared to determine the time of entering into plastic phase. The expression of the dynamical coefficient of resistance in the elastic-plastic phase was derived. Calculation examples show that the applicable range of the polynomial curve fitting attenuation load is greater than that of the linear equivalent load. The curve shape adjustment factor,which is a feature of polynomial curve fitting attenuation load,has some effect on the dynamical coefficient. The linear equivalent load is simpler in solving and easier in application. The dynamical coefficient based on the linear equivalent load is inclined to be somewhat greater in the case of low ductility ratio,which is beneficial for structural design. It is inclined to be smaller in the case of high ductility ratio and high structural rigidity. The result even is 19% lower than the result based on the polynomial curve fitting attenuation load. Obviously it is detrimental for structural design.

关 键 词：化学爆炸 动力系数 等效单自由度 等效静载 作用时长 

分 类 号：TU312.1[建筑科学—结构工程] TU352.1