In order to establish a restoring-force model for modified concrete columns with recycled aggregates concrete(RAC), cyclic loading tests were carried out on five concretes with RAC columns and ordinary concrete frame ...In order to establish a restoring-force model for modified concrete columns with recycled aggregates concrete(RAC), cyclic loading tests were carried out on five concretes with RAC columns and ordinary concrete frame columns under the combined influence with different admixtures and admixtures ratios(silica fume and hybrid fiber). The expressions for characteristic nodes of the skeleton curve were given by the analysis and numerical regression of the test results. In addition, the hysteretic rules of the restoring-force model and the expression for unloading stiffness were presented. Finally, we summed up the complete calculation method of the hysteretic restoring force, whose results were in good agreement with experiment. The results demonstrated that the proposed model could simulate and reflect the corresponding hysteretic behaviors, and the calculation method can provide the theoretical basis for the engineering application.展开更多
为明确MSS、Casciati和Harvey and Gavin这3种常用双向恢复力模型计算基础隔震建筑风振响应的差异,采用3种模型模拟铅芯橡胶支座在水平单向和双向位移下的恢复力,对比试验或有限元结果的差异,采用3种模型对一算例在双向风荷载下隔震层...为明确MSS、Casciati和Harvey and Gavin这3种常用双向恢复力模型计算基础隔震建筑风振响应的差异,采用3种模型模拟铅芯橡胶支座在水平单向和双向位移下的恢复力,对比试验或有限元结果的差异,采用3种模型对一算例在双向风荷载下隔震层位移、顶点位移和顶点加速度3个指标的差异进行了分析。研究表明:3种模型模拟铅芯橡胶支座在单向循环位移、方形和偏置方形位移下恢复力的趋势基本一致;而模拟圆形和偏置圆形位移时,MSS模型双向恢复力形状与有限元结果不同,不能较为准确地模拟支座双向耦合行为,Casciati模型误差稍小于Harvey and Gavin模型。Casciati模型和Harvey and Gavin模型计算风振响应基本一致;对于横风向响应均方根,3种模型差距不大;对于顺风向隔震层位移、顶点位移和顶点加速度均方根,MSS模型稍小,而对于顺、横风向隔震层位移峰值因子,MSS模型稍大;对于顺、横风向顶点加速度峰值因子和双向与单向模型顶点加速度最值比值随风速变化规律,MSS模型与其他模型差异较大。基于双向耦合效应模拟及风振响应指标的差异,建议采用Casciati模型考虑双向恢复力模型对基础隔震建筑风振响应的影响。展开更多
鉴于恢复力曲面法(Restoring Force Surface,RFS)和随机森林(Random Forest,RF)模型在参数辨识领域的优越性,结合上述两种方法提出一种新的基于RFS-RF的局部非线性模型辨识方法。首先,针对局部非线性模型求解其动力响应。其次,根据获得...鉴于恢复力曲面法(Restoring Force Surface,RFS)和随机森林(Random Forest,RF)模型在参数辨识领域的优越性,结合上述两种方法提出一种新的基于RFS-RF的局部非线性模型辨识方法。首先,针对局部非线性模型求解其动力响应。其次,根据获得的动力响应计算恢复力曲面与边际谱,然后再通过边际谱求解非线性指标。再次,通过多次改变结构的刚度和阻尼参数生成若干组非线性指标并建立随机森林模型。然后,将新的非线性指标作为预测集输入已经建立的随机森林模型并判断系统的非线性类型和非线性函数形式。最后,采用最小二乘法对局部非线性系统的待求参数进行精确识别。通过一个四层剪切型框架结构模型对所提方法进行验证,研究结果表明:基于RFS-RF的多自由度局部非线性模型辨识方法能够准确识别结构系统的非线性类型、函数形式以及未知参数。展开更多
基金Project(51178388)supported by the National Natural Science Foundation of ChinaProject(2013SZS01-Z02)supported by Key Laboratory Fund of Shaanxi Province,China
文摘In order to establish a restoring-force model for modified concrete columns with recycled aggregates concrete(RAC), cyclic loading tests were carried out on five concretes with RAC columns and ordinary concrete frame columns under the combined influence with different admixtures and admixtures ratios(silica fume and hybrid fiber). The expressions for characteristic nodes of the skeleton curve were given by the analysis and numerical regression of the test results. In addition, the hysteretic rules of the restoring-force model and the expression for unloading stiffness were presented. Finally, we summed up the complete calculation method of the hysteretic restoring force, whose results were in good agreement with experiment. The results demonstrated that the proposed model could simulate and reflect the corresponding hysteretic behaviors, and the calculation method can provide the theoretical basis for the engineering application.
文摘为明确MSS、Casciati和Harvey and Gavin这3种常用双向恢复力模型计算基础隔震建筑风振响应的差异,采用3种模型模拟铅芯橡胶支座在水平单向和双向位移下的恢复力,对比试验或有限元结果的差异,采用3种模型对一算例在双向风荷载下隔震层位移、顶点位移和顶点加速度3个指标的差异进行了分析。研究表明:3种模型模拟铅芯橡胶支座在单向循环位移、方形和偏置方形位移下恢复力的趋势基本一致;而模拟圆形和偏置圆形位移时,MSS模型双向恢复力形状与有限元结果不同,不能较为准确地模拟支座双向耦合行为,Casciati模型误差稍小于Harvey and Gavin模型。Casciati模型和Harvey and Gavin模型计算风振响应基本一致;对于横风向响应均方根,3种模型差距不大;对于顺风向隔震层位移、顶点位移和顶点加速度均方根,MSS模型稍小,而对于顺、横风向隔震层位移峰值因子,MSS模型稍大;对于顺、横风向顶点加速度峰值因子和双向与单向模型顶点加速度最值比值随风速变化规律,MSS模型与其他模型差异较大。基于双向耦合效应模拟及风振响应指标的差异,建议采用Casciati模型考虑双向恢复力模型对基础隔震建筑风振响应的影响。
文摘鉴于恢复力曲面法(Restoring Force Surface,RFS)和随机森林(Random Forest,RF)模型在参数辨识领域的优越性,结合上述两种方法提出一种新的基于RFS-RF的局部非线性模型辨识方法。首先,针对局部非线性模型求解其动力响应。其次,根据获得的动力响应计算恢复力曲面与边际谱,然后再通过边际谱求解非线性指标。再次,通过多次改变结构的刚度和阻尼参数生成若干组非线性指标并建立随机森林模型。然后,将新的非线性指标作为预测集输入已经建立的随机森林模型并判断系统的非线性类型和非线性函数形式。最后,采用最小二乘法对局部非线性系统的待求参数进行精确识别。通过一个四层剪切型框架结构模型对所提方法进行验证,研究结果表明:基于RFS-RF的多自由度局部非线性模型辨识方法能够准确识别结构系统的非线性类型、函数形式以及未知参数。
