摘要
在地震作用下，由于榫、卯之间相互挤压，产生较大的塑性变形，其转动变形刚度退化，凸显出其“柔性”连接特征，使整个结构的抗侧移刚度降低，从而有效地减轻了地震对结构的破坏作用。基于试验滞回曲线，分别建立了相应的节点力矩-转角位移和水平力-位移的恢复力模型，引入了量化其耗能减振能力的“滞回耗能因子”，并建立了相应的理论计算公式，对榫卯节点和斗栱模型的耗能因子进行了计算，结果表明，斗栱结构的滞回耗能因子高于榫卯节点的1-2个数量级，因而从理论上证明了铺作（即斗栱）层应是木结构古建筑的主要减振与隔震作用结构层。
The pseudo-static tests of the mortise-tenon joint models and the bucket arch models are carried out respectively and the test results show that, under horizontally reversal action, being squeezed by each other, the mortise and the tenon would get an overall plastic deformation, which leads to looser connection between them, and degeneration of rotational rigidity as well as evident flexible characteristic of mortise-tenon joints and, consequently greatly reduces the possible damage to stucture; similarly, the deflection stiffness of the bucket arch is always descended no matter whether the action is increasing or decreasing. On the basis of the mortise-tenon joint and the bucket arch hysteretic loops, the corresponding restoring moment-rotation model of the bucket arch mortise-tenon joint models, as well as the bilinear force-displacement relation of the bucket arch models are established respectively. The ＂hysteretic energy dissipation factor fhed＂ that can evaluate quantitively the energy dissipation capacity of mortise-tenon joint or the bucket arch is introduced, furthermore, the corresponding theoretical calculated formula of fhed is also presented, as well as the values of fhed corresponding mortise-tenon joint models and the bucket arch models are calculated respectively. The results show that, the fhed for bucket arch models are about 1 -2 order of magnitude as big as that of mortise-tenon joint models; hence, it is confirmed theoretically that the bucket arch structure is the main vibration reduction and shock isolation construction in ancient Chinese timber buildings.
出处
《自然灾害学报》
CSCD
北大核心
2008年第2期58-64,共7页
Journal of Natural Disasters
基金
国家自然科学基金项目(59878043)
西安市科技局科技攻关社会发展项目(GG05171)
西安建筑科技大学科技计划基础研究基金项目(JC0722)
关键词
斗栱
榫卯节点
滞回耗能因子NL
隔震
bucket arch
mortise-tenon joint
hysteretic energy dissipation factor
seismic isolation
