【作者】 李磊；

【导师】 王来贵；

【作者基本信息】 辽宁工程技术大学 ， 固体力学， 2011， 硕士

【摘要】 我国房屋建筑中许多重要结构,如山墙等承重结构体,多为砖砌材料。而砖砌体等材质统称为岩石类材料,具有脆性性质,从而窗体结构承重墙整体上具有准脆性特性,在动力作用下容易发生脆性破坏。由于岩石类材料具有脆性性质和低抗拉特性,如果在强震动力作用下而承受拉应力状态的岩石类窗体结构,就极易发生拉张破裂,使得结构体沿着垂直主拉应力方向扩展破裂,形成不连续面,这就是脆性材料结构体拉张破裂的基本原理。传统的有限元计算法,是建立在连续性假设基础之上,不能模拟结构体拉张破裂后形成的不连续状态,所以不能直接处理结构体拉破坏问题,动力作用下非连续介质破坏的模拟研究更是甚少。而有限元语言是一种采用有限元方法求解偏微分方程的模型语言,采用这种语言编写有限元程序,其主要工作就是书写微分方程表达式及其有限元算法,然后由该语言的生成器自动产生某种高级语言的有限元计算程序。本文基于脆性材料拉张破裂判据,提出单元开裂准则,通过FORTRAN语言编写出三角形单元开裂贯通子程序。采用相对的方法,将地震加速度考虑为边界约束,根据牛顿第二定律,从而结构整体上施加一个反向作用力。基于动力开裂机理的研究,模拟窗体承重墙不同结构形式下动态应力场变化,并分析地震荷载瞬时拉张应力下的脆性破坏。通过对单窗体、双窗体和多窗体三种结构形式分析,在地震波加速度时程变化过程中,窗体结构体角点产生应力集中,其拉压应力值随之发生变化和重新分布。拉应力最大值点出现开裂,并且地震加速度值越大,拉应力水平就越高,最终产生初始的拉张裂纹,随着拉张区域的扩展,裂纹向结构内部延伸,呈现X形的拉张裂纹纹理,导致窗体结构破坏。更多还原

【Abstract】 Many important structures of housing construction in china, such as gables and other load-bearing structure, mostly brick material. The brick masonry and other materials collectively referred to as rock-like materials with brittle nature of the structural load-bearing wall to form a quasi-brittle characteristics of the whole, likely to occur under the dynamic brittle failure.Traditional finite element method, is built on the basis of the continuity assumption, can not simulate the structure formed after tensile fracture is not a continuous state, so the structure can not deal directly with tensile failure problems under dynamic simulation of non-continuum damage study is even less.The language is a finite element finite element method to solve partial differential equations modeling language, the use of finite element program written in this language, and its main job is to write differential expressions and finite element method, and then by the language generator a high-level language automatically generated finite element program.Based on the tensile fracture criterion for brittle materials, fracture criterion proposed unit, through the FORTRAN language routines through a triangular element cracking.Relative to the method used, the seismic acceleration boundary constraints considered, according to Newton’s second law, which the whole structure a reverse force is applied. Cracking mechanism based on dynamic studies, simulations under different structural forms load-bearing walls form dynamic stress field change, and analyze the seismic load transient tensile brittle failure under stress. On a single form, the form of three two-form and multi-structure analysis of seismic wave acceleration time history in the process of change, the form structure corner stress concentration, the tensile and compressive stress will be changed and re-distribution . The maximum tensile stress cracking point, and the larger the value of earthquake acceleration, the higher the level of tensile stress, eventually produce the initial tension cracks, with the expansion of regional tension, the crack extends to the internal structure, showing X-shaped tensile of crack texture, leading to form structural damage.更多还原