【作者】 曲哲；

【导师】 叶列平；

【作者基本信息】 清华大学 ， 土木工程， 2010， 博士

【摘要】 强震下的损伤机制控制是保证建筑结构抗震安全的关键。本文在结构体系设计和抗震需求分析两个层次上系统地研究了摇摆墙-框架结构的抗震性能和基于损伤机制控制的抗震设计方法。主要研究工作和成果如下:1.基于通用有限元程序ABAQUS开发了用于纤维截面杆系单元的钢筋与混凝土单轴本构滞回模型,通过与试验数据的对比,验证了该模型在模拟钢筋混凝土杆系结构非线性地震响应方面的合理性。2.比较了动力弹塑性分析中常用的地震动记录选取方法,通过算例分析指出了结构在非线性响应阶段的等价周期对不同地震动记录选取方法效果的影响。建立了适用于评估不同建筑结构抗震性能的地震动记录选择集。3.通过研究摇摆墙-框架结构的变形模式与摇摆墙刚度之间的关系,提出了确定摇摆墙刚度需求的实用方法;通过对典型工程的计算分析指出,摇摆墙-框架结构在不同地震动作用下变形模式能够得到有效控制,结构损伤沿楼层分布比较均匀,具有优越的抗震性能。在此基础上,提出了符合我国工程抗震设防要求,适宜在我国推广应用的摇摆墙-框架结构体系。4.系统研究并完善了计算结构非线性地震峰值响应的等代结构法。首先,通过定性和定量地讨论结构主要参数的影响,基于大量非线性计算结果的统计分析,建立了新的能够全面反映主要参数影响的单自由度等价线性化模型。在此基础上,完善了等代结构法的计算流程和关键步骤,并通过算例分析指出,等代结构法能够比较准确的计算结构的非线性地震峰值响应,且具有适用性广,计算效率高等特点,适宜在工程抗震设计中推广应用。5.以等代结构法为基础,提出了基于损伤机制控制的抗震设计方法。与现行规范方法相比,该方法可定量分析结构中具有不同抗震性能目标的构件在非线性地震响应阶段的抗震能力需求,以保证预期损伤机制的实现。通过将其分别用于钢筋混凝土框架结构和摇摆墙-框架结构的抗震设计算例,验证了该方法的合理性。更多还原

【Abstract】 The control of seismic damage mechanism is of crucial importance for the safety of building structures subjected to strong earthquakes. The research in this dissertation makes a contribution in both the system design philosophy and the seismic demand analysis by studying the seismic performance of rocking wall-frame structure and proposing a damage mechanism control-based seismic design methodology. Major achievements of the dissertation are as follows:1. Uniaxil hysteretic models for steel rebars and concrete are developed for fiber beam elements and implemented in a finite element software ABAQUS. Calibrated with existing experimental data, the model is proved applicable in simulating the nonlinear seismic response of reinforced concrete frame structures.2. Commonly-used methods of selecting earthquake ground motion records for nonlinear dynamic analysis are evaluated and compared through case studies. The influence of the equivalent period of damaged structure on the effectiveness of different selection methods is presented. Earthquake strong ground motion suites appropriate for evaluating the seismic performance of various building structures are established.3. The relationship between the extent of story drift concentration and the stiffness of rocking wall in a rocking wall-frame structure is studied, based on which a practical equation for determining the stiffness demand for rocking wall is proposed. The superior seismic performance of rocking wall-frame structures over moment-resisting frames is demonstrated though comprehensive analysis of a typical rocking wall-frame structure with emphasis on its well-controlled deformation pattern and more uniformly distributed damage. A simplified rocking wall-frame structure is proposed for the use in less-developed earthquake prone regions.4. Substitute structure analysis (SSA) as a method of predicting the nonlinear seismic peak responses of building structures is studied. As a basis, a new equivalent linear model for single-degree-of-freedom system is proposed based on comprehensive discussions, both conceptually and quantitatively, in the influence of various structural parameters on equivalent linear parameters. The procedure of substitute structure analysis is completed and errors studied. The performance of substitute structure analysis in predicting the nonlinear seismic peak responses of building structures is proved adequate for seismic design practice through several case studies. The wide applicability and high computational efficiency of SSA are demonstrated.5. In determining the seismic demands of building structures, a damage mechanism control-based seismic design procedure is proposed with SSA as its analysis basis. The seismic damage mechanism is expected to be under control by means of explicitly determining the required strength and deformability of structural members with different seismic performance objectives. A moment resisting frame and a rocking wall-frame structure with similar structural layouts are designed using the proposed procedure to prove its rationality.更多还原