钢筋混凝土框架的静、动损伤分析-结构工程专业论文.docxVIP

摘 摘 要 混凝土作为一种土木工程中普遍应用的材料，其破坏机理和破坏形态一直是材 料学、力学和工程技术界所共同关心的问题，结构的破坏控制一直是工程设计的关 键所在。结构的破坏不会突然发生，而是损伤积累的结果。破坏控制的目的就是制 止结构在服役期内发生这种灾难性的完全破坏，即控制结构的损伤在容许范围以 内。 断裂力学为混凝土结构的破坏分析与控制提供了理论框架。但由于断裂力学有 一定的局限性，损伤力学理论随之产生与发展，这种理论可用于分析结构破坏的整 个过程，即微裂纹的演化、宏观裂纹的形成直至构件的完全破坏。 本文将前人提出的静、动力双剪损伤本构关系进行了一定的修正与完善，使原 来的动力双剪损伤本构考虑了动力荷载作用下材料的初始弹性模量的提高效应，从 而更加符合动力作用下混凝土本构关系的实际。其次，本文推导出了增量形式的损 伤演化方程，这样使原来只适合于单调加载的损伤演化方程，适用于复杂加卸载情 况。 现有非损伤型本构模型在分析结构应力应变方面已经很成熟且与试验结果符 合很好。基于此，本文提出了一种损伤有限元分析的全解耦的方法，充分利用现有 成熟的通用有限元软件进行结构的应力应变分析，然后结合APDL自编程序来进行 混凝土框架结构静力、动力和地震作用下的损伤分析，得到了关于混凝土框架结构 损伤分布以及损伤场随荷载与时间的演化情况，为结构的损伤评估、寿命预测提供 了基础。 关键词：钢筋混凝土；框架；损伤分析；静力损伤：动力损伤；地震损伤；双剪 理论；本构方程 AbstractConcrete Abstract Concrete is a material applied extensively in the civil engineering．The failure mechanism and the failure mode of the concrete are concerned by the experts in the fields of the material science，the mechanics，and the engineering．111e failure control is the key problem to the design in engineering．The failure of a structure doesn’t happen suddenly, but usually is because of the damage accumulation．The target of the failure control is to prevent the total failure during the service period，namely,to control the extension of the micro—cracks and the micro．cavities within the allowable extent． Fracture mechanics provide the theory for the failure analysis and the control of the RC structure．But，because of the limitation of fracture mechanics，the damage mechanics is proposed．The theory Can be used to analyze the total failure process of the structure including the evolution of the micro-cracks，the formation of the macro—cracks and the failure of the members． In this paper,the static，dynamic double-shear damage constitutive theory is modified． By considering the variety of initial elastic modulus under dynamic load，the constitutive equation is improved to be more reasonable．And the increment form of the damage evolution equation is derived in order to be applicable under complicated load． The non—damage constitutive model