考虑损伤累积效应的单层球面网壳动力稳定

为了揭示强震下单层网壳结构的动力失效机理,从考虑材料损伤累积效应的角度出发,基于塑性应变和能量损耗理论建立应变-损伤弹塑性本构关系,提出将B-R运动准则和杆件塑性应变能密度曲线结合起来,作为结构动力失稳的判断标准.应用动态增量(IDA)法,对一Kiewitt-8型单层球面网壳结构进行地震作用下动力稳定分析,得出考虑材料损伤累积效应将显著降低结构的动力稳定临界荷载等结论,为该类结构震后修复和抗震性能的评估提供依据.

Dynamic Stability of Single-layer Latticed Shells Considering Damage Accumulation Effect

To address the dynamical instability of single-layer latticed shells under earthquake excitation, proceeding from the damage accumulative effect of steel material, the constructive relationship between strain and damage was first set up on the basis of the theory of both plastic strain and energy dissipation. Then, the criterion for dynamic stability by means of B-R kinetic criterion in combination with plastic strain energy density was put forward. The method of incremental dynamic analysis was used to study the dynamic stability of a Kiewitt-8 type single-layer latticed shell under earthquake excitation when considering the damage accumulation effect. Finally, some conclusions are obtained that strain-damage constitutive mode can reflect the features of structural failure and greatly affect the structure, which may be helpful in engineering repair and the estimation of seismic capacity.