结构震害可分为位移首超破坏与累积损伤破坏两种模式,其根源均是某一瞬时段内结构能量耗储能力与地震耗储需求不匹配所造成的。基于对结构震害的这一认识,将结构地震损伤定义为结构在单向水平荷载作用下耗散塑性应变能与存储弹性应变能能力的损失,并构建结构地震损伤量化模型。该模型能清晰描述结构的两种破坏模式,并对“位移损伤”与“退化损伤”进行分离,物理意义明确,应用相对简单。采用56条地震波对3种周期的SDOF结构进行损伤分析,发现控制结构在地震作用下的峰值位移能够控制结构的总损伤,这当中既包括控制结构的“位移损伤”,也包括控制结构的“退化损伤”;而减小结构由于振动平衡位置偏离而产生的不可恢复位移与降低结构的强度衰减是控制结构损伤最为有效的2个途径。
The common reason of first excursion failure and cumulative damage failure is that seismic energy dissipation and storage demand are greater than the capability of structure in a momentary input interval. As a result, seismic damage is defined as the loss of structural energy dissipation and storage capability under one-way horizontal loads, and a seismic damage quantitative model which can separate "displacement damage" and "degradation damage" is proposed. Based on the model, the seismic damage analysis of three SDOF structures with different periods by 56 ground motions are carried out. The results show that the peak displacement is strongly related to structural totaldamage, which includes "displacement damage" and "degradation damage". The decrease of the residual displacement caused by the deviation of a vibration balance position and reduced structural strength degradation will control seismic damage effectively.