钢框架结构的连续倒塌动力响应分析

发布时间：2018-02-12 13:37

本文关键词： 钢框架结构连续倒塌非线性动力分析拆除构件法爆炸载荷　出处：《山东建筑大学》2013年硕士论文　论文类型：学位论文

【摘要】：随着中国土木工程行业的迅猛发展,钢结构体系得到了更加广泛的应用。目前工程界对钢结构建筑在常规载荷作用下的设计已经比较完善,而对于各种偶然载荷(如火灾、汽车撞击及爆炸等)作用引起的结构连续倒塌行为还存在许多值得探讨的内容。众所周知,结构的连续性倒塌通常会造成较为严重的后果,对人民的生命财产安全构成重大威胁,故对钢结构连续倒塌的分析和研究具有显著的社会意义。对钢结构进行连续倒塌分析时,现在应用较为广泛的两种分析方法是拆除构件法和直接施加偶然载荷法。第一种方法不考虑结构构件破坏的具体原因,简化了结构的分析过程；第二种方法针对不同类型的偶然荷载分别进行分析。本文利用有限元软件ANSYS/LS-DYNA,基于这两种分析方法,对平面和空间钢框架结构进行非线性动力分析,主要进行了一下几个方面的研究： (1)基于拆除构件法,分析了平面钢框架结构中柱失效时间、失效位置及材料的应变率对结构动力响应的影响,同时对底层边柱失效时,结构的内力重分布和动力响应的影响区域进行分析,得出：构件的拆除时间不应大于剩余结构竖向振动周期的1/10；底层边柱失效引起的结构动力响应较大；应考虑材料的应变率对结构的影响。底层边柱时,靠近失效柱的各轴柱轴力、各梁弯矩、各梁轴力变化较为显著,远离失效柱的各构件内力受影响较小。 (2)同样利用拆除构件法对某空间钢框架结构进行连续倒塌动力分析,由于底层角柱失效和短边中柱失效引起的动力响应较大,所以对底层角柱和短边中柱失效时,剩余结构的内力变化和动力响应的影响区域进行研究。 (3)利用直接施加爆炸载荷法,引入失效准则,将该空间钢框架结构底层角柱消除,分析柱失效前后剩余各构件的内力变化情况和动力响应的影响区域。 (4)对比利用两种方法分析结构底层角柱失效时,结构的位移响应、内力重分布和动力响应的影响区域有何异同。通过比较得出：撤柱前后,结构中内力的变化趋势基本一致,但拆除构件法的模拟结果偏小。所以,如果结构构件失效是由于爆炸载荷作用引起的,应利用对结构直接施加爆炸载荷的方法进行分析,不建议采用拆除构件法对结构进行连续倒塌动力分析。
[Abstract]:With the rapid development of civil engineering industry in China, steel structure system has been applied more widely. The continuous collapse of structures caused by vehicle impact and explosion still has much to be discussed. As we all know, the continuous collapse of structures usually results in serious consequences. It is a great threat to the safety of people's life and property, so it is of great social significance to analyze and study the continuous collapse of steel structures. In the continuous collapse analysis of steel structures, the two widely used analysis methods are the method of removing members and the method of directly applying accidental load. The first method does not consider the concrete reasons of the failure of structural members. In this paper, the nonlinear dynamic analysis of plane and spatial steel frame structures is carried out based on the finite element software ANSYS- LS-DYNA. Mainly carried out the following aspects of research:. 1) based on the method of removing members, the effects of failure time, failure position and strain rate of material on the dynamic response of the structure in plane steel frame structure are analyzed. By analyzing the influence area of the internal force redistribution and the dynamic response of the structure, it is concluded that the demolition time of the member should not be greater than 1 / 10 of the vertical vibration period of the residual structure, and the dynamic response of the structure caused by the failure of the bottom side column is larger. The influence of strain rate of material on the structure should be considered. When the bottom column is near the failure column, the axial force, bending moment and axial force of each beam are significantly changed, while the internal forces of the members far away from the failure column are less affected. (2) in the same way, the method of removing members is used to analyze the continuous collapse dynamic of a space steel frame structure. Because of the failure of the bottom corner column and the short side column, the dynamic response of the bottom corner column and the short side column is larger, so when the bottom corner column and the short edge column fail, The influence area of internal force and dynamic response of residual structure is studied. 3) by directly applying explosive load method and introducing failure criterion, the bottom corner column of the spatial steel frame structure is eliminated, and the variation of internal force and the influence area of dynamic response of each remaining member before and after column failure are analyzed. In this paper, the displacement response, internal force redistribution and dynamic response of the structure are analyzed by using two methods. It is concluded that the variation trend of the internal force in the structure is basically the same before and after the column withdrawal. However, the simulation results of the method of removing the components are small. Therefore, if the failure of the structural members is caused by the effect of the explosive load, the method of directly applying the explosive load to the structure should be used to analyze the failure of the structural members. It is not recommended to use the method of removing members to analyze the continuous collapse dynamic of the structure.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU391;TU311.3

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