基于弹塑性损伤和多性能目标的多高层重型木框架结构抗震分析

Heavy timber framed structures are advantageous regarding flexible architectural layout and high space utilization. To promote the multi-story timber framed structures in China will help reduce the enormous amount of resource consumption of the construction industry and ease the situation of construction land shortage in urban areas, and eventually catch up with the international advanced levels in application of modern timber structures..The proposed research is based on the challenges of more significant impact of the behavior of the bolted connections on the increased seismic requirements of the multi-story timber structures that often are controlled by displacement rather than internal forces in earthquake scenarios. Experimental and numerical studies have been incorporated to carry out the research work, which includes, in addition to the applicant’s results on bolted glulam connections and shake table tests of a five-story glulam framed structure, cyclic loading tests of wood in parallel and perpendicular to wood grain directions, real-time monitoring and measuring of processing damage during drilling of wood specimens, embedment loading tests of wood and lateral cyclic loading tests of individual timber frames considering use of various connection reinforcement techniques and steel-wood buckling restrained bracing members..Elastoplastic damage mechanics, high-speed digital image correlation and fragility analysis techniques will be employed in conjunction of tensorial analysis of the stresses and strains of wood to address the major academic and technical issues, including the elastoplastic damage mechanism of wood under tension and compression, the processing damage from drilling on surrounding wood, and the multiple seismic performance targets of multi-story timber framed structures. Eventually, the performance based seismic analysis method for multi-story heavy timber framed structures will be proposed with relevant reinforcing methods verified at a structural level..The proposed research work has been oriented from fundamental problems. The generated knowledge will help improve the seismic analysis and design methods for heavy timber framed structures. It can also be used as reference for steel-wood, concrete-wood and bamboo-wood hybrid structures, and thus benefits the academic research and engineering application of modern timber and bamboo structures in China in the long run.

重型木框架结构较普通木结构布局更为灵活、空间利用率高。积极推进重型木框架结构多高层建筑有助于缓解我国建筑资源能耗过高和城市建筑用地紧缺的局面，赶超国际木结构先进水平。多高层重型木框架结构抗震能力受限于节点滞回性能和过大的地震位移响应。项目采取试验和数值模拟并行的研究路线，基于申请人已有胶合木梁柱螺栓节点和五层胶合木框架结构振动台试验数据，开展木材顺/横纹低周反复加载、钻孔加工损伤、木材销轴承压和含增强节点和钢木屈曲约束支撑的木框架墙低周反复加载等试验，运用弹塑性损伤理论、高速摄影测量和结构抗震易损性分析等技术，解决木材弹塑性损伤机理、节点钻孔加工致损机制和多性能目标抗震分析等关键问题，完善多高层重型木框架结构抗震分析理论和性能提升技术。项目聚焦共性问题，针对多高层重型木框架结构的抗震研究成果也可为钢木、混凝土木和竹木等组合结构性能研究提供参考，进一步提升我国竹木结构研究理论和工程应用水平。

课题围绕多高层重型木框架结构抗震性能，采用拟静力加载试验、弹塑性损伤数值模拟和理论分析，完成了考虑木材顺纹单边效应的弹塑性损伤行为表征、顺纹拉压反复受力的扭折性能、考虑钻孔损伤的木材顺纹销轴承压性能、螺栓节点简化滞回模型及其关键参数取值、基于多性能目标的重型木框架结构抗震性能分析和基于自攻螺丝和屈曲约束支撑等技术的重型木框架结构抗震性能提升技术等六项研究工作，提炼形成了反复荷载作用下的木材弹塑性损伤行为表征方法、螺栓节点荷载-位移滞回行为精细化数值模拟和简化滞回模型、多性能目标的重型木框架结构抗震性能分析以及重型木框架结构抗震性能提升技术等4项技术，研究成果发表SCI、EI收录期刊论文各6篇，获批4项发明专利，培养了2位博士研究生和6位硕士研究生，并获批基金委面上项目一项以持续开展研究。