Unified Earthquake Response Analysis for Reinforced Concrete Structures

(1)开发了钢筋混凝土结构的非弹性地震反应分析程序，其中构件的恢复力是根据材料的应力-应变关系确定的。这个程序可以应用于相当简单的结构，如单柱式桥墩。但由于计算时间较长，对刚架结构等复杂结构不太适用。(2)制定了第二个程序，其中将结构的每个成员划分为段；在同一段内，假设矩曲率关系相同。有了这种理想化，该程序可以实际应用于复杂的结构。(3)在采用Clough滞回模型作为弯矩曲率关系的第二程序中，在适当的承载能力下，以节段长度等于塑性铰的长度，第二程序的计算结果与振动台试验和拟动力试验结果在承载能力降低前的范围内吻合较好。即使在承载能力降低后，只要在弯矩-曲率关系中考虑承载能力降低后的曲率，程序仍然可以准确地确定响应。(4)当受弯屈服后发生剪切裂缝时，弯矩-曲率关系下的承载力降低过程不一定能反映该现象的真实性质。严格地说，抗剪刚度也应相应降低。这是一个需要进一步调查的研究领域。(5)最大加速度发生的时间和振幅接近最大值的加速度次数对钢筋混凝土结构的响应有显著影响。在产生用于反应分析的合成地震时应考虑到这一点。少

(1) A program for inelastic earthquake response analysis of reinforced concrete structures has been developed, in which the restoring forces of the members are determined based on stress-strain relationship of the materials. This program can be applied to rather simple structures such as single-column type piers. However, because of the long computation time needed, the program is not practical for complicated structures such as rigid-frame type structures.(2) A second program has been developed in which each member of a structure is divided into segments ; and within a segment, the same moment-curvature relationship is assumed. With this idealization, this program can be practically applied to complicated structures.(3) In the case of adopting Clough hysteresis model as the moment-curvature relationship in the second program using the proper load-carrying capacities and taking the segment lengths to be equal to the lengths of the plastic hinges, the results given by the second program … More agree well with experimental results of shaking-table tests and pseudodynamic tests in the range before the decrease of load-carrying capacities. Even after the load-carrying capacities have decreased, the response can still be determined accurately by the program as long as the curvature in the reduced load-carrying capacity is taken into account in the moment-curvature relationship.(4) When shear cracks occurs after flexural yielding, the procedure of lowering the load-carrying capacity in the moment-curvature relationship does not necessarily reflect the true nature of the phenomenon. Strictly speaking, the shear rigidity should also be decreased accordingly. This is an area of research that needs further investigation.(5) The elapsed time when the maximum acceleration occurs and also the number of times of acceleration with amplitude close to the maximum value have significant influence on the response of reinforced concrete structures. This should be taken into account in generating the synthetic earthquake for use in response analysis. Less