摘要
采用单自由度体系等效多自由度体系,只考虑第一振型影响,确定结构最大位移反应。该文假定R.C框架结构屈服前刚度与强度相关,屈服位移由结构几何尺寸近似确定。结合我国建筑抗震设计规范,研究不同设计条件下R.C框架结构的超强系数,然后乘以设计地震作用确定结构的实际强度。根据结构屈服位移以及实际强度确定等效结构的有效周期。当有效周期大于特征周期时,结构最大非线性位移反应采用等位移原理确定,当有效周期小于特征周期时,结构最大非线性位移反应采用等能量原理确定。该方法与其它方法相比,避免了复杂的弹塑性动力或静力分析,不需要进行迭代计算,且与我国规范结合紧密,特别适合对既有结构快速评估。
MDOF system is equivalent to SDOF system with bilinear force-deformation relations, representing the first mode of structures. It is assumed that yield displacement is the function of the geometry of components and the yield strain of the reinforcing steel, and that structural stiffness is dependent on strength. Overstrength factors of reinforced concrete frames are studied under different design parameters based on seismic design code. The practical strength is calculated through design strength multiplied by the overtstrength factor. The effective period of equivalent SDOF is determined by yield displacement and practical strength. When the effective period is longer than site character period, then the maximum inelastic deformation is determined by equal displacement approximation. When the effective period is shorter than site character period, then the maximum inelastic deformation is determined by equal energy approximation. This method avoids inelastic dynamic analysis, so it pushes over the analytical speed, and there is no necessity for iterations. Also, it is specially employed by quick evaluation of existing buildings.
出处
《工程力学》
EI
CSCD
北大核心
2007年第12期113-119,共7页
Engineering Mechanics
基金
上海市重点学科建设基金赞助
上海交通大学校内青年教师科研启动基金
关键词
钢筋混凝土框架结构
屈服位移
超强系数
有效周期
等位移原理
reinforced concrete frame
yield displacement
overstrength factor
effective period
equal displacement approximation
