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Evaluation of Seismic Resistance of Reinforced Concrete Structures Based on Pseudodynamic Test

基于拟动力试验的钢筋混凝土结构抗震评价

基本信息

批准号：
63850108
负责人：
MACHIDA Atsuhiko
金额：
$ 2.82万
依托单位：
Saitama University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1989
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63850108/
关键词：
pseudodynamic test step-by-step loading strain rate effect single degree of freedom system reinforced concrete structures evaluation of seismic resistance 擬似動的実験振動実験アンダーシュート誤差

项目摘要

1. Errors due to undershoot, which has been considered to be one of the problematic points in pseudodynamic test, can be made negligibly small if allowable difference between target displacements and attained ones is made as small as possible and the increments of displacement to attain a target displacement are decreased in a geometric ratio.2. In pseudodynamic test, the restoring force at each loading step is underestimated due to load drop which occurs during the calculation process for the target displacement of next step, and if such underestimation occurs at a step, the test is carried out based on incorrect data afterwards. To overcome this, it is necessary to modify the measured restoring forces. Though the amount of the modification is not very large, the modification is needed at almost all loading steps.3. In pseudodynamic test, restoring forces are also underestimated sometimes owing to its static loading process, in which strain rate effect is neglected. Since the amount of underestimation is considerably high though it rarely occurs, the underestimated restoring forces should be modified to obtain correct results.4. We developed a pseudodynamic testing system, taking all of the results described above into consideration. The developed system can simulate satisfactorily accurately responses to earthquakes of reinforced concrete structures of single degree of freedom. It gives one of possible responses to such a severe loading that peak response displacements increase continuously and force the load carrying capacity to enter its descending range.5. The future issues of the developed system are to evaluate universally the needed modifications and to enlarge the applicable range to multi degree of freedom system.

1.由于下冲引起的误差一直被认为是拟动力试验中的问题点之一，如果目标位移和实际位移之间的允许差值尽可能小，并且达到目标位移的位移增量按几何比减小，则可以使误差小到可以忽略不计.在拟动力试验中，由于在计算下一步目标位移的过程中出现载荷下降，导致每个加载步的恢复力被低估，如果在某一步出现这种低估，则随后根据错误的数据进行试验。为了克服这一点，有必要修改测量的恢复力。虽然修改量不是很大，但几乎在所有加载步骤都需要修改.在拟动力试验中，由于其加载过程为静力加载，忽略了应变率效应，有时也会低估恢复力。由于低估的数量相当高，虽然它很少发生，低估的恢复力应进行修改，以获得正确的结果。我们开发了一个拟动力测试系统，考虑到所有上述的结果。所开发的系统可以令人满意地准确地模拟单自由度钢筋混凝土结构的地震反应。它给出了一种可能的反应，这样一个严重的负载，峰值响应位移不断增加，并迫使承载能力进入其下降范围.未来发展的系统的问题是普遍评估所需的修改，并扩大适用范围的多自由度系统。