考虑多种损伤因素的钢框架结构分析模型

AN ANALYTICAL MODEL FOR STEEL FRAME STRUCTURE CONSIDERING VARIOUS DAMAGE FACTORS

钢框架结构在强震作用下产生损伤,结构的刚度和强度等力学性能随之降低,从而影响到结构以后的抗震性能,为避免灾难性事故的发生,准确评估有损伤结构的承载力尤为重要。在梁-柱理论的基础上,推导节点有损伤梁的弯矩计算公式,并通过修正梁的转角位移方程建立了半刚性连接钢框架结构的梁单元刚度方程。通过数值算例分析节点损伤、材料损伤和已有变形等因素对钢框架结构受力性能的影响,结果表明不同因素对结构变形和构件内力影响的程度不同,对有损伤钢框架结构进行承载力评估时必须综合考虑各种因素的影响。

Damage will occur in steel frame structure under severe earthquakes,and its mechanical properties will decrease accordingly,such as stiffness,strength and so on.As a result,this degradation has a significant effect on the seismic performance of steel frame structure.In order to avoid catastrophic accident,an accurate assessment of bearing capacity of the damaged structure is particularly important.Based on beam-column theory,the calculation formula of bending moment for beam with damaged joints was derived in this paper.The stiffness equation of beam element with semi-rigeid connections was also established through modifying the angular displacement equation of beam.The influence of joint damage,material damage,existing deformation and other factors on steel bearing capacity were analyezed through a numerical example.The results showed that the influence of various factors on structure deformation and internal force was different.Therefore,various damage factors must be taken into account to evaluate the load bearing capacity of damaged steel frames.