强烈地震作用下钢框架的损伤退化行为

发布时间：2018-05-27 11:09

本文选题：钢框架 + 累积损伤退化　；参考：《清华大学》2013年博士论文

【摘要】：在强烈地震作用下，传统的杆系模型对于钢框架的构件、节点发生承载力和刚度退化特征无法准确模拟和预测，往往会低估结构变形、高估结构抗倒塌能力，存在一定的安全隐患。本文对钢框架的损伤退化机理、关键影响参数及损伤退化过程进行了深入研究，提出了能够更准确模拟整体结构损伤退化行为的理论模型。通过程序开发，实现了钢框架杆系模型考虑损伤退化全过程的弹塑性动力时程分析，发展了一种有效的强震分析手段。论文的工作主要包含以下六个方面：（1）对比研究十种损伤指数模型对参考文献中两批节点试验损伤退化过程的描述，探讨不同损伤指数模型对结构破坏预测的准确性，并分析不同模型的适用范围（第2章）。（2）完成50个Q235B和Q345B钢材在10种加载制度下的循环加载试验，提出了考虑循环强化作用的钢材滞回本构模型SHCM（Steel Hysteretic ConstitutiveModel）。利用有限元软件ABAQUS，二次开发了相应计算程序，并得到大量试验验证，为后续提出考虑损伤退化的等效本构模型提供了基础理论框架（第3章）。（3）结合已有构件和节点试验，在第3章模型研究的基础上，提出了能够准确模拟累积损伤退化现象、预测损伤退化全过程的数值分析方法（第4章）。（4）基于第4章研究成果，对构件、节点进行参数分析，深入剖析损伤退化控制因子及其影响程度、损伤退化过程及“三折线”退化曲线分布规律（第5章）。（5）建立了考虑损伤退化行为的“等效本构模型”，利用定义损伤退化控制因子对结构地震响应进行深度描述。利用ABAQUS软件平台二次开发了能够进行损伤退化全过程分析的用户材料子程序DDAP （Damage and DegradationApplication Program）。模型得到了已有钢框架静力试验和振动台试验的充分验证,并应用于北岭地震实际破坏的钢框架变形以及损伤预测中（第6章）。（6）通过与壳单元模型、多尺度模型及传统杆系模型进行比较，证明本文提出的考虑损伤退化的等效本构模型提高了钢框架杆系模型在强烈地震作用下动力时程分析和破坏预测的准确性，，兼顾计算效率，为强震分析提供技术支持。在此基础上，得到了累积损伤退化对不同层数钢框架抗震评价指标的影响程度和规律，并提出了用于损伤破坏控制的退化指数预测曲线（第7章）。本论文在国家自然科学基金项目（编号：90815004和51038006）资助下完成。
[Abstract]:Under the action of strong earthquake, the characteristics of bearing capacity and stiffness degradation of joints in steel frame can not be accurately simulated and predicted by the traditional bar model, which often underestimate the deformation of the structure and overestimate the ability of the structure to resist collapse. There are certain safety risks. In this paper, the damage degradation mechanism, key influence parameters and damage degradation process of steel frame are deeply studied, and a theoretical model which can more accurately simulate the damage degradation behavior of the whole structure is put forward. The elasto-plastic dynamic time-history analysis of the steel frame bar system model considering the whole process of damage degradation is realized by programming, and an effective method of strong earthquake analysis is developed. The work of the thesis mainly includes the following six aspects: 1) A comparative study of ten damage index models describing the damage degradation process of two batches of nodal tests in reference is made, the accuracy of different damage index models for structural damage prediction is discussed, and the applicability of different models is analyzed (Chapter 2). (2) the cyclic loading tests of 50 Q235B and Q345B steels under 10 loading systems were completed, and a hysteresis constitutive model SHCM(Steel Hysteretic Constitutive Model was proposed. By using the finite element software Abaqus, the corresponding calculation program is developed twice, and a large number of tests are carried out, which provides a basic theoretical framework for the subsequent development of the equivalent constitutive model considering damage degradation (Chapter 3). Based on the model study in Chapter 3, a numerical analysis method is proposed to accurately simulate cumulative damage degradation and predict the whole process of damage degradation (Chapter 4). 4) based on the research results in Chapter 4, the parameters of components and nodes are analyzed, and the damage degradation control factor and its influence degree, the process of damage degradation and the distribution law of "three broken lines" degradation curve are analyzed (Chapter 5). (5) an equivalent constitutive model considering damage degradation behavior is established, and the structural seismic response is described in depth by using the defined damage degradation control factor. Using ABAQUS software platform, a user material subroutine, DDAP damage and DegradationApplication program, which can analyze the whole process of damage degradation, is developed. The model is fully verified by the static test and shaking table test of the steel frame, and is applied to the deformation and damage prediction of the steel frame damaged by the Beiling earthquake (Chapter 6). By comparing with shell element model, multi-scale model and traditional bar system model, It is proved that the proposed equivalent constitutive model considering damage degradation can improve the accuracy of dynamic time history analysis and failure prediction of steel frame member system model under strong earthquake and provide technical support for strong earthquake analysis. On this basis, the influence degree and law of cumulative damage degradation on seismic evaluation index of steel frame with different layers are obtained, and the prediction curve of degradation index for damage and failure control is proposed (Chapter 7). This thesis is supported by the National Natural Science Foundation of China (Nos.: 90815004 and 51038006).
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU391;TU311.3

【参考文献】