基于有效耗能的改进Park-Ang双参数损伤模型及其计算研究

THE RESEARCH AND CALCULATION ON MODIFIED PARK-ANG DOUBLE PARAMETER SEISMIC DAMAGE MODEL BASED ON ENERGY DISSIPATION

Park-Ang双参数地震损伤模型考虑了地震作用的首次超越破坏与累积损伤破坏两方面因素,较好的定义了结构的破坏,被后续研究广泛应用,但无法区分不同幅值作用下结构破坏的差异。分析了不同位移幅值下钢筋混凝土柱的破坏特点,研究了结构损伤与结构耗能之间的关系。试验表明弹性阶段(位移幅值小于一倍屈服位移)的试件几乎不发生破坏,造成钢筋混凝土柱破坏的能量集中在相持阶段和破坏阶段,定义非弹性阶段引起结构破坏的滞回耗能为导致结构破坏的有效耗能。基于有效耗能假设引入有效耗能因子e,提出了改进的Park-Ang双参数地震损伤模型。对建议模型进行了21组钢筋混凝土柱的试验数据验证,计算结果表明:有效耗能因子可以反映相同耗能下不同位移幅值引起的结构破坏差异,有效耗能因子e物理意义明确,改进后的双参数地震损伤模型计算精度高,离散性小,能够区分不同位移幅值下钢筋混凝土柱的破坏差异,较好地评估了RC结构的损伤性能。

The Park-Ang double parameter seismic damage model has been widely used due to the consideration of first exceedance failure and cumulative damage failure in terms of defining the structural damage under earthquake. However, it does not consider the differences between structural failures with different displacement amplitudes. Based on past experimental research, the damage properties of the reinforced concrete columns under different displacement amplitudes were mainly analyzed, and the relationship between the structure damage and the structural energy dissipation was studied. Past experiments indicated the specimens scarcely failed during the elastic stage, but failed when more energy obsorbed during the developing and fail stage. In this study, effective energy dissipation is proposed instead of using hysteric energy dissipation when describing the cause of structural damage during the inelastic stage. It is suggested that the hysteric energy dissipation during the non-elastic stage is termed as the effective energy dissipation that causes structure failure. Based on the assumption of effective energe dissipation, the effective energy dissipation factor is introduced and a modified Park-Ang double-parameter seismic damage model is proposed. The proposed model is verified by the test data of2 l groups of reinforced concrete columns.With the same dissipated energy, the effective energy dissipation factor is proved to show the differences between the structural failures led by different displacement amplitudes. The Definition of the effective energy dissipation factor is thusly explicit, the double parameter seismic damage model is improved with higher computational accuracy and less discreteness, it also tell the failure differences between the reinforced concrete columns under different displacement amplitudes and evaluate the damage level of the RC structure well.