钢筋混凝土悬臂梁材料阻尼值计算

Calculation of material damping of reinforced concrete cantilever beams

提出一种计算钢筋混凝土构件材料阻尼值的新方法。基于Lazan的研究理论,利用OpenSEES系统,采用Giuffré-Menegotto-Pinto钢本构模型、Kent-Scott-Park混凝土本构模型及Karsan-Jirsa加卸载准则,计算钢筋混凝土构件在正应力作用下弹性阶段的单位体积损耗能量,并通过SPSS统计分析软件回归建立了钢筋混凝土材料单位体积耗能与最大正应力幅值、混凝土抗压强度及配筋率的关系式。采用解析方法计算钢筋混凝土悬臂梁弹性阶段在简谐荷载作用下的材料阻尼值,为进一步了解钢筋混凝土材料性能及准确分析计算钢筋混凝土结构动力响应打下了良好基础。

A new method is presented to compute material damping of reinforced concrete （RC） components. Based on the material damping and stress amplitude relation of Lazan, the area of hysteresis loop of RC components under axial cycle load is calculated with Giuffr6-Menegotto-Pinto steel constitution model, Kent-Scott-Park concrete constitution model and Karsan-Jirsa loading-unloading law in OpenSEES system, obtaining energy dissipation of RC. The results indicate that energy dissipation per unit of RC increases with the increase of maximum stress amplitude and decreases with the increase of concrete strength. The relation formula of energy dissipation of RC with maximum stress amplitude, concrete strength and reinforcement ratio is established with nonlinear regression. The material damping value of RC cantilever beam in elastic stage under harmonic excitation is computed by the analytical method and it will be helpful in material behavior study of RC and dynamic response computation of RC structures.