损伤古建筑木构架抗震性能退化机理的研究

项目名称： 损伤古建筑木构架抗震性能退化机理的研究

项目编号： No.51478409

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 建筑科学

项目作者： 李胜才

作者单位： 扬州大学

项目金额： 82万元

中文摘要： 现存古建木构普遍存在碳化、裂缝、蛀蚀、压溃、断裂等损伤问题，导致其结构性能下降，是古建木构抗震性能评价与维护研究的难点。本项目基于古木材与构件损伤和变形特征的调研和评估，通过模拟复杂交变环境与负载工况，研制损伤试验模型；以材料试验为基础，研究古木材性特征与受载变化模型；对非受损和不同种类损伤状态下的柱子、梁枋、榫卯节点进行静动载试验，分析节点在地震作用下的承载特性和传载机制、木构件的刚度和承载力指标；对比分析非受损和损伤节点、构件的基本力学性能和退化程度，分别给出强度、承载力、刚度与损伤参数的变化关系；建立木构架有限元模型，研究残损古建木构在地震作用下的极限变形、承载力与破坏模式，给出地震作用下的位移/转角与应力/承载力相关性曲线；分析各类节点与构架的变形、破坏及其分布、时序等，建立古建木构损伤模型。项目预期成果可为保护损伤古建木构文化遗产、改善其抗震性能，提供理论支撑、技术参数与途径。

中文关键词： 古建筑木结构；抗震性能；损伤试件设计；退化机理；损伤模型

英文摘要： It is well known that the aseismic performances of Chinese traditional timber structures are excellent. However, the degeneration problems on material behaviour, open fractures,decayed by insects and pythium, partial crush, shear cracks, unrecoverable plastic deformation,weak connections between structural members,and other issues of ancient building timber structures have commonly been arisen as they have been experiencing or bearing various impacts accompanying their long-standing history. These problems led to the degradation of aseismic performances of ancient building timber structures. Based on the characteristics of aged timber, damage and deformation of the components in timber structure building, damaged and undamaged test specimens will be developed under the complex alternating simulating climate environment with some key influencing media and various load conditions. The material models of aged timber will be studied on the basis of the mechanic tests on corresponding timber specimens. The static tests and dynamic tests on the damaged and undamaged specimens of columns, beams, mortise-tenon joints made from timber will be conducted. The load-bearing characteristics and transferring mechanism of the joints, the stiffness and bearing capacity of timber members could be refined on the basis of test data. The basic mechanical properties and degradation degree of joints and timber members could be sorted out by the comparison on the data from the tests of damaged and undamaged specimens. The correlation curve of strength, bearing capacity, stiffness related to the damage degree could be extracted. The finite element model of timber frames would be established. The failure mode, deformation and ultimate bearing capacity of damaged timber frames under the action of earthquake combined with certain load conditions would be analyzed by FEM. The correlation curve on displacement / drift to stress / bearing capacity under a given earthquake action could be concluded. The damage evolving model would be fitted by numerical analysis and corresponding validating test on the deformation, damage, time-sequence and their distribution of timber joints and structure system. The goals of this research proposal could be to provide theoretical foundation, analysis framework, technical parameters and support methodologies on improving the aseismic performances of ancient building timber structure and preventing them from earthquake disaster.

英文关键词： Timber structure of Chinese building heritage;Aseismic behaviour;Damaged specimen design;Degradation mechanism;Damaged model