强震作用下高层不规则钢框架结构的倒塌模式

发布时间：2018-05-31 12:13

本文选题：高层不规则钢框架 + 倒塌模式　；参考：《安徽理工大学》2017年硕士论文

【摘要】：近年来,随着高层、大跨度公共建筑的增长,其结构强震倒塌越来越受到关注。如何能准确地反映高层不规则钢框架结构在强震作用下的倒塌模式已成为一个课题,本文基于此课题运用ANSYS和LS-DYNA软件对高层不规则钢框架结构在强震倒塌全过程进行模拟分析。本文主要研究的内容及结论如下:(1)通过对不规则高层钢框架结构进行模态分析,得到结构有楼板模型的一阶频率为0.63543HZ,无楼板模型一阶频率为0.65971HZ,基频较低,说明结构的整体刚度较大,满足结构的整体性和合理性;一阶振型都以平动为主,说明结构受横向振动影响较大,而对竖向振型表现不明显。(2)通过对不规则高层钢框架结构进行非线性动力分析,结构的有楼板模型最大层间位移均出现在第二层,在350gal的Elcentro波作用下,最大层间位移为0.0412m,在该峰值加速度的Elcentro波作用下层间最大位移角为1/80,并未超过高层或超高层弹塑性层间位移角为1/50的限值。结构的无楼板模型最大层间位移也都出现在第二层,在350gal的Elcentro波作用下,最大层间位移为0.0202694m,在该峰值加速度的Elcentro波作用下层间最大位移角为1/164,也未超过高层或超高层弹塑性层间位移角为1/50的限值。不规则高层钢框架结构的各层最大加速度曲线呈缓"S"型上升,最大加速度出现在顶层。(3)通过对不规则高层钢框架结构进行倒塌分析,分别输入Elcentro波、Taft波和人工波三种地震波可得出有楼板模型先从底层的柱子开始失效,在三种地震波作用下失效构件占总杆件个数分别为3.47%、3.39%、3.3%。底层柱子失效导致结构发生整体倒塌,则不规则高层钢框架结构有楼板模型为动力失稳破坏。无楼板模型也是从底层的柱子开始失效,在三种地震波作用下失效构件占总杆件个数分别为2.75%、3.57%、2.93%。底层柱子失效导致结构发生整体倒塌,则不规则高层钢框架结构无楼板模型为动力失稳破坏。在三种地震波作用下可得出的结构顶点三向位移曲线,从X、Y向顶点位移曲线可得出结构倒塌的时间和结构在地震波作用下的震动范围,从Z向顶点位移曲线能清晰地看出结构的倒塌时间。在三种地震波作用下可得出结构的三向加速度曲线,从曲线中都能判断结构的倒塌时间。
[Abstract]:In recent years, with the growth of tall buildings and large span public buildings, more and more attention has been paid to the collapse of large-span public buildings. How to accurately reflect the collapse mode of high-rise irregular steel frame structure under strong earthquake has become a topic. Based on this topic, this paper uses ANSYS and LS-DYNA software to simulate and analyze the whole process of high-rise irregular steel frame structure collapsing under strong earthquake. The main contents and conclusions of this paper are as follows: (1) through modal analysis of irregular high-rise steel frame structure, the first order frequency of the structure with floor model is 0.63543 HZ, the first order frequency of no floor model is 0.65971HZ, and the fundamental frequency is lower. It shows that the overall stiffness of the structure is large, which satisfies the integrity and rationality of the structure, and that the first order modes are mainly translational, indicating that the structure is greatly affected by transverse vibration. But the vertical vibration mode is not obvious. (2) through nonlinear dynamic analysis of irregular high-rise steel frame structure, the maximum interstory displacement of the structure with floor model appears in the second floor, under the action of Elcentro wave of 350gal. The maximum interlayer displacement is 0.0412m, and the maximum displacement angle between the lower layers is 1 / 80 when the Elcentro wave acts on the peak acceleration, which does not exceed the limit of 1 / 50 of the elastoplastic interlayer displacement angle of the upper or super-high layers. The maximum interstory displacement of the structure without floor model also appears in the second floor, under the action of Elcentro wave of 350gal, The maximum interlayer displacement is 0.020 2694 m, and the maximum displacement angle between the lower layers of the Elcentro wave with the peak acceleration is 1 / 164, and does not exceed the limit of 1 / 50 of the elastoplastic interlayer displacement angle of the upper or super-high layers. The maximum acceleration curve of irregular high-rise steel frame structure rises slowly in "S" shape, and the maximum acceleration appears on the top floor. (3) the collapse analysis of irregular high-rise steel frame structure is carried out. Three kinds of seismic waves, Elcentro wave Taft wave and artificial wave, respectively, can be obtained that the failure of the floor model begins with the column at the bottom, and the number of the failure member in the total member is 3.47 and 3.39 respectively under the action of the three kinds of seismic waves. The failure of the bottom column results in the collapse of the whole structure, and the dynamic instability of the irregular high-rise steel frame structure is caused by the floor model. The failure of the model is also from the bottom column. Under the action of three kinds of seismic waves, the number of failure members is 2.75 and 3.57 and 2.93 respectively. The failure of the bottom column results in the collapse of the whole structure, and the dynamic instability of the irregular high-rise steel frame structure without floor model. Under the action of three kinds of seismic waves, the three dimensional displacement curve of the structure vertex can be obtained. From the displacement curve of the XY direction, the time of collapse of the structure and the range of vibration of the structure under the action of the seismic wave can be obtained. The collapse time of the structure can be clearly seen from the displacement curve of Z direction vertex. Under the action of three kinds of seismic waves, the three-dimensional acceleration curve of the structure can be obtained, and the collapse time of the structure can be judged from the curve.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU973.1

【参考文献】