K型偏心支撑钢框架在循环荷载作用下的力学性能分析

发布时间：2018-05-19 12:24

本文选题：偏心支撑钢框架 + 耗能梁段　；参考：《兰州理工大学》2013年硕士论文

【摘要】：偏心支撑钢框架在正常使用阶段,具有较大的抗侧力刚度,结构侧移较小；在大震作用下,利用耗能梁段的塑性变形耗散地震能量,具有良好的耗能效果,是一种比较理想的多高层钢结构抗侧力体系,尤其适用于高烈度震区,K型偏心支撑钢框架是其中比较常见的一种。研究表明,耗能梁段的长度在1.0Mp｜Vp-1.3Mp|Vp圪范围内时,耗能梁段具有最佳的耗能能力,但是好多时候,为了满足建筑构造的要求,要把耗能梁段做得短一些,长度很难在这个范围。耗能梁段越短,耗能梁段上的剪力就越大,容易使其发生剪切破坏。根据耗能梁段发生剪切破坏的特点,在耗能梁段上加了斜加劲肋,以防止过早的剪切破坏。文中设计了12组耗能梁段长度不同的试件,应用有限元软件ABAQUS分析了加与不加斜加劲肋和斜加劲肋加得多少两种情况下,框架结构性能的变化。本文在分析过程中,所有的构件都采用了壳单元,对于进入弹塑性阶段的耗能梁段同时考虑了几何非线性和材料非线性,其他的构件只考虑了几何非线性,材料的强化采用了混合强化法则,非线性方程通过Newton-Raphson迭代法结合增量法求解。通过分析得出的主要结论是：相比在整个耗能梁段上不加斜加劲肋和只在耗能梁段的两端加斜加劲肋,在整个耗能梁段上加斜加劲肋后,承载力、弹性和弹塑性刚度都提高了,割线刚度退化得慢了,耗能梁段的实际长度与基本长度Mp|%的比值较小时,框架的弹性位移较大,滞回曲线更饱满,耗能能力更强,但随着比值接近1或大于1,弹性位移相比较小,耗能能力变差。因此,当耗能梁段的长度与基本长度Mp|Vp名的比值较小时,在整个耗能梁段上加斜加劲肋后,能延迟耗能梁段的破坏,增加结构的耗能能力。
[Abstract]:The eccentrically braced steel frame has large lateral force stiffness and small lateral displacement in normal use. Under the action of large earthquake, the plastic deformation of energy dissipation beam section can dissipate seismic energy, which has a good energy dissipation effect. It is an ideal lateral force resistance system for multi-high-rise steel structures, especially for K-type eccentrically braced steel frames in high intensity seismic areas. The results show that the energy dissipation beam section has the best energy dissipation capacity when the length of the energy dissipation beam section is within the 1.0Mp Vp-1.3Mp VP GE range, but in many cases, in order to meet the requirements of the building construction, the energy dissipation beam segment should be made shorter, and the length is difficult to be in this range. The shorter the energy dissipation section, the greater the shear force on the energy dissipation beam segment, and the shear failure is easy to occur. According to the characteristics of shear failure in the section of energy-dissipating beam, inclined stiffening rib is added to the section of energy-dissipated beam to prevent premature shear failure. In this paper, 12 groups of specimens with different length of energy-consuming beams are designed, and the performance changes of the frame structure are analyzed by using the finite element software ABAQUS under the condition of adding or not adding oblique stiffeners and how many oblique stiffeners are added. In this paper, the shell element is used for all the components in this paper. The geometric nonlinearity and material nonlinearity are considered for the energy dissipation beam in the elastic-plastic stage, while the other members only consider the geometric nonlinearity. The material strengthening is based on the mixed strengthening rule, and the nonlinear equations are solved by the Newton-Raphson iterative method and the incremental method. The main conclusions are as follows: compared with the whole energy dissipation beam section, the bearing capacity, elasticity and elastic-plastic stiffness of the whole energy dissipation beam section are improved after the oblique stiffening rib is added to the whole energy dissipation beam section and the two ends of the energy dissipation beam section are only added with the oblique stiffening rib. The stiffness of the Secant degenerates slowly, the ratio of the actual length to the basic length of the beam section is smaller, the elastic displacement of the frame is larger, the hysteretic curve is fuller, and the energy dissipation ability is stronger. However, when the ratio is close to 1 or greater than 1, the elastic displacement is smaller and the energy dissipation capacity becomes worse. Therefore, when the ratio of the length of the energy dissipation beam segment to the basic length of the energy dissipation beam segment is small, the damage of the energy dissipation beam segment can be delayed and the energy dissipation capacity of the structure can be increased after the oblique stiffening rib is added to the whole energy dissipation beam section.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU391

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