RC框架结构基于能量抗震性能评估方法研究

发布时间：2018-06-28 16:07

本文选题：等效速度谱 + 累积塑性变形能　；参考：《西安建筑科技大学》2014年博士论文

【摘要】：基于能量抗震设计方法融合了力和位移这两个重要的结构设计参数，能够全面反映地震作用对结构的影响，但如何将能量概念用于具体结构的抗震设计仍是一个具有挑战性的课题。本文针对RC框架结构基于能量抗震性能评估方法进行了系统深入的研究。主要工作如下：对比了四种不同类型单自由度（SDOF）体系的地震能量时程反应、地震动总输入能及瞬时输入能分配情况；对比了多自由度（MDOF）体系相对位移和绝对位移能量平衡方程表示的总输入能、最大瞬时输入能及其出现时间的差异。提出了一种适用于我国场地土类型，且便于实际应用的弹塑性SDOF体系归一化等效速度谱。将从美国PEER地震记录数据库选取的220条强震记录按中国场地土类型进行分类，并以此作为地震输入。建议了一种基于复合强度指标的弹性SDOF体系三段式归一化等效速度谱。分析了五类场地土条件下刚度折减系数、延性系数和阻尼比对SDOF体系归一化等效速度谱的影响，进而提出了一种适用于我国场地土类型，且便于实际使用的弹塑性SDOF体系归一化等效速度谱，，并验证了该方法的有效性。推导了累积塑性变形能需求量及其沿结构各层的分配系数。基于能量平衡原理和多模态等效单自由度(ESDOF)体系的概念，推导了剪切型MDOF体系累积塑性变形能需求量及其沿结构各层的分配系数。在此基础上，通过16种工况下的单因素敏感性分析，对累积塑性变形能分配系数公式进行简化，以便于工程应用。同时得出以下结论：累积塑性变形能分配系数主要由质量、屈服剪力系数、刚度和累积塑性变形倍数四个因素决定；顶层参数变化对累积塑性变形能分布无明显影响；逐层递减和中间层薄弱情况下，各层分配的累积塑性变形能与屈服剪力系数和累积塑性变形倍数呈正相关，与刚度呈反相关；中间薄弱层释放的累积塑性变形能按其相邻两层原累积塑性变形能大小之比进行重新分配。提出了一种基于层的“半解析半数值”双参数损伤模型。针对既有双参数损伤模型基于构件损伤指数判定结构各层及整体损伤时，计算工作量大，容易产生累积误差，且判定结果受构件损伤指数组合方式影响较大的不足。结合第四章研究成果，针对RC框架结构，提出了一种基于层的“半解析半数值”双参数损伤模型，弥补了既有构件损伤模型对各层进行损伤评估时的不足。并将应用本文损伤模型计算得到的层间损伤模式与Park-Ang模型的计算结果进行对比，验证了本文所提出模型的有效性。分析了RC框架结构的耗能需求及分布规律。通过改变周期折减系数，近似考虑填充墙对RC框架结构在大震作用下耗能分布的影响，并给出定量计算方法。根据弹塑性时程分析得到的累积塑性变形能沿楼层的分布情况，对第四章推导的各层累积塑性变形能分配系数公式进行修正。结合现有的基于能量抗震设计方法，提出了RC框架结构基于能量抗震性能评估方法，对RC框架结构在大震下的层间损伤模式和安全性进行评估。根据前面各章研究成果，给出基于能量抗震性能能评估方法的一般步骤，并通过算例说明了该方法的应用。
[Abstract]:The two important structural design parameters, such as force and displacement, can fully reflect the impact of seismic action on the structure, but it is still a challenging task to apply the energy concept to the seismic design of concrete structures.
In this paper, the energy based seismic performance evaluation method of RC frame structure has been systematically studied. The main work is as follows:
The seismic energy time history response of four different types of single degree of freedom (SDOF) system, the total input energy of ground motion and the distribution of instantaneous input energy are compared, and the total input energy of the relative displacement and the absolute displacement energy balance equation of the MDOF system is compared, and the difference of the maximum transient input energy and its occurrence time is compared.
A kind of elastoplastic SDOF system normalized equivalent velocity spectrum is proposed, which is suitable for the type of soil and soil in China and is convenient for practical application. 220 strong earthquakes selected from the PEER seismic record database of the United States are classified according to the type of Chinese soil and soil, and as an earthquake input, an elastic SDOF body based on the composite strength index is proposed. The three segment normalized equivalent velocity spectrum is used to analyze the influence of the stiffness reduction coefficient, the ductility coefficient and the damping ratio on the normalized equivalent velocity spectrum of the SDOF system under the condition of five types of ground soil, and then a kind of normalized equivalent velocity spectrum is proposed which is suitable for the type of soil and soil in our country and is convenient for the actual use of the elastoplastic system, and the formula is verified. The validity of the law.
The accumulative plastic deformation energy demand and the distribution coefficient along each layer are derived. Based on the energy balance principle and the concept of multimodal equivalent single freedom (ESDOF) system, the accumulative plastic deformation energy demand and the distribution coefficient along the structure of the shear type MDOF system are derived. On this basis, the single factor sensitivity under 16 operating conditions is carried out. The formula of cumulative plastic deformation energy distribution coefficient is simplified to facilitate engineering application. At the same time, the following conclusion is drawn that the cumulative plastic deformation energy distribution coefficient is mainly determined by four factors, such as mass, yield shear coefficient, stiffness and cumulative plastic deformation multiplier, and the variation of roof parameters has no explicit development on cumulative plastic deformation energy distribution. The cumulative plastic deformation of each layer is positively correlated with the yield shear coefficient and the cumulative plastic deformation multiple, and the cumulative plastic deformation can be redistributed according to the ratio of the cumulative plastic deformation energy of the two adjacent layers.
A double parameter damage model of "semi analytic semi numerical" based on layer is proposed. The calculation work is large and the cumulative error is easy to be produced when both the structure layers and the whole damage are determined based on the component damage index based on the damage index of the two parameter damage model, and the result is greatly influenced by the combination of damage index of the component. According to the RC frame structure, a double parameter damage model of "semi analytic semi numerical" based on layer is proposed, which makes up for the deficiency of damage assessment of the existing damage model of the existing component, and compares the interlayer damage model calculated with the damage model in this paper with the calculation results of the Park-Ang model. The validity of the proposed model is proposed.
The energy consumption demand and distribution law of the RC frame structure are analyzed. By changing the cycle reduction coefficient, the influence of the filling wall on the energy dissipation distribution of the RC frame structure under large earthquake action is considered, and the quantitative calculation method is given. According to the elastoplastic time history analysis, the cumulative plastic deformation can be distributed along the floor, and the fourth chapters are derived. The formula of cumulative energy distribution coefficient of plastic deformation is corrected.
Combined with the existing energy seismic design method, the RC frame structure based on the energy seismic performance evaluation method is proposed to evaluate the interlayer damage mode and safety of the RC frame structure under large earthquakes. According to the research results of the previous chapters, the general steps based on the evaluation method of energy seismic performance are given, and the example is illustrated by an example. The application of this method.
【学位授予单位】：西安建筑科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TU375.4;TU352.11

【参考文献】