古木材性测试及木构一字榫卯节点力学性能分析

发布时间：2018-06-28 04:27

本文选题：古建木构 + 古木小试件测试　；参考：《北京交通大学》2014年硕士论文

【摘要】：摘要：我国拥有众多以木构架为主要承重体系的古建筑,这类古建筑木结构(简称古建木构)具有极高的建筑结构科技成就,正面临着维护修缮与可持续开发利用等诸多难题,亟需有效地修复措施与保护方案。古建木构是由榫卯节点连接而成的木质杆系结构,而表现出高度非线性与显著耗能性能。榫卯节点形制、用材与摩擦机理复杂,是解决古建木构难题的关键。本文对古木样本进行了材料试验与分析：归纳了古建木构的关键部位,对其中的一字榫卯节点进行了力学性能分析与简化,来为古建木构体系分析提供参考。在山西省万荣县飞云楼的现场微震测试与节点测量中,收集了废弃的古木碎木样本,为解决其无法进行标准材性试验的难题,利用特殊设计的小试件进行了古木材性测试,并得到了古木样本基本力学性能的全过程曲线。通过形态、密度、纹理特征与色泽对古木样本进行了所属构件的归类。根据古木小试件试验结果,归纳并提出了古木样本的材料模型；提出了由正交各向异性弹性层与GASKET层复合的层模型,来模拟古木横纹承压能力；利用强度失效准则对古木断裂性能进行了模拟,并提取了未测得的材料参数。结合古建木构现场考察及大量古建筑史料研究,归纳并提取了不同形制古建木构的关键部位,并对其类型与构造进行了确定。在以应县木塔为工程实例的结构体系分析基础之上,对关键部位中的一字榫卯节点进行了力学性能分析研究,提出了适用于古建木构结构体系的混合杆系计算模型。混合杆系模型由梁单元、刚性梁、半刚性单元、承压单元及断裂单元构成,并由节点足尺试验确定了所需计算参数。计算结果能反应出节点受拉失效、额枋横纹压屈与木柱劈裂等非线性性能,还突出了与竖向荷载水平相关的滞回耗能性能,且计算与实验结果基本吻合。
[Abstract]:Abstract: there are many ancient buildings with wooden frame as the main bearing system in our country. This kind of ancient building wood structure (called ancient construction wood) has very high scientific and technological achievements of architectural structure. It is facing many difficult problems such as maintenance and repair and sustainable exploitation and utilization. It is urgent to repair measures and protection schemes effectively. The ancient construction wood structure is the joint of mortise and tenon joints. The woody rod system, which is formed, shows high nonlinearity and significant energy dissipation. The form of mortise and tenon joints and the complex friction mechanism are the key to solve the problem of ancient wood construction. This paper carried out the material test and analysis of the ancient wood samples: the key parts of the ancient construction wood were summed up, and the strength of the mortise and tenon joints was carried out. The analysis and simplification of academic performance will provide reference for the analysis of ancient timber structure.
In the field microseismic test and node measurement of the flying cloud building in Wanrong County, Shanxi Province, the abandoned ancient wood samples were collected to solve the problem that it was unable to carry out the standard timber test. The ancient wood properties were tested by the specially designed small specimen, and the whole process curve of the basic mechanical properties of the ancient wood samples was obtained. The texture features and color of the ancient wood samples are classified. According to the test results of the ancient wood small specimen, the material model of the ancient wood sample is summed up and proposed. A layer model composed of the orthotropic elastic layer and the GASKET layer is put forward to simulate the compressive strength of the old wood cross grain, and the fracture property of the ancient wood by the strength failure criterion is used. It can simulate and extract the unmeasured material parameters.
Based on the site investigation of ancient construction wood and a large number of historical materials of ancient buildings, the key parts of different forms of ancient construction wood are summed up and extracted, and their types and structures are determined. On the basis of the structural system analysis of the Yingxian Wood Tower as an example, the mechanical properties of the joint tenon and mortise joint in the key parts are analyzed and studied. A hybrid rod system model is proposed for the ancient construction of wooden structures. The mixed bar system model is composed of beam element, rigid beam, semi rigid element, pressure unit and fracture unit, and the required parameters are determined by the full scale test of nodes. The calculation results can reflect the non line of the joints, such as the failure of the joints, the bending of the horizontal lines and the splitting of the wood columns. The hysteretic energy dissipation performance is also related to the vertical load level, and the calculated results are basically consistent with the experimental results.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU366.2

【参考文献】