钢木螺栓节点木框架抗火性能研究

发布时间：2018-07-17 02:39

【摘要】：火灾造成我国木结构损失严重,而目前我国木框架层次的抗火性能研究及灾后评估方法的研究尚处于基础性的探索阶段。如何在火灾后的现场对木框架进行简便易行的检测鉴定,并评估其结构安全状态是急需解决的重要问题。本文设计了梁柱式钢-木螺栓节点连接的胶合木框架,对其进行指定按照IS0834标准升温曲线受火10分钟和20分钟下的火灾试验后进行灭火。总结对比不同受火时间下木框架受火性能差异,总结木框架炭化速度规律和火灾损伤机理。从受火后木构件中截取木材小试件进行材性试验及基于阻抗仪的无损检测试验,材性试验包括密度和抗弯强度、顺纹和横纹抗压强度、顺纹弹性模量试验等物理和力学参数指标。并建立了可用于火灾后木材试件材性参数指标无损检测的线性回归方程。在前文获得的受火后木材材性参数的线性回归方程基础上,对受火后木框架构件进行阻抗仪检测试验,分析受火后木构件材性性能变化。将各测点的阻抗值代入关系曲线,获得小试件材性性能指标。在考虑小试件与构件之间材性差异影响因素后,最终可以获得受火后木材构件的材性参数。对受火试验后木框架进行极限承载力试验,研究木框架荷载-位移曲线、截面应变变化等基本力学性能及受火后极限承载力变化情况与破坏规律,为木框架的剩余承载力评估提供试验依据。结合无损检测获得的木构件的材性参数,采用Abaqus对受火后木框架进行数值模拟,分析验证其极限承载力及破坏规律,验证采用火灾后木材无损检测方法结合有限元实现对木结构剩余承载力评估的可行性。
[Abstract]:The fire caused serious loss of wood structure in China, but the research on fire resistance and post-disaster assessment of wood frame in China is still in the basic stage of exploration. It is an important problem that how to detect and identify the wooden frame and evaluate its structural safety status in the fire site. In this paper, the glued wood frame connected with Liang Zhu type steel-wood bolt joint is designed, and the fire test is carried out in accordance with IS0834 standard heating curve for 10 minutes and 20 minutes. The difference of wood frame under different fire time was summarized, and the carbonization rate and fire damage mechanism of wood frame were summarized. The wood properties test and the non-destructive testing test based on impedance meter are carried out from the wood members after fire. The wood properties tests include density and bending strength, compression strength of parallel and transverse lines, Physical and mechanical parameters such as elastic modulus test. A linear regression equation was established for nondestructive testing of wood properties of wood specimens after fire. On the basis of the linear regression equation of wood property parameters obtained in the previous paper, the wood frame members after fire were tested by impedance meter, and the changes of wood properties after fire were analyzed. The impedance of each measuring point was substituted into the curve to obtain the properties of the small specimen. After considering the factors that affect the wood properties between the small specimens and the components, the wood properties parameters of the wood components after fire can be obtained. The ultimate bearing capacity of wood frame after fire test was tested. The basic mechanical properties of wood frame such as load-displacement curve, cross-section strain change, and ultimate bearing capacity change and failure law after fire were studied. To provide the test basis for the evaluation of the residual bearing capacity of the wood frame. Combined with the wood property parameters obtained by non-destructive testing, Abaqus was used to simulate the wood frame after fire, and the ultimate bearing capacity and failure law of the frame were analyzed and verified. The feasibility of evaluating the residual bearing capacity of wood structure by using the method of wood nondestructive testing after fire and finite element method was verified.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.6;TU352.5

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