素混凝土轴压构件单位体积材料耗能公式建立

Formula for Unit Material Energy Dissipation of Plain Concrete Components Under Axial Cycle Load

利用OpenSEES系统,基于Lazan材料阻尼与应力关系的研究理论,采用Hognestad混凝土本构关系模型及Karsan-Jirsa加卸载准则,计算素混凝土构件在轴向重复荷载作用下的滞回曲线包围面积,得到混凝土正应力作用下单位体积损耗能量.分析计算结果表明,素混凝土材料单位体积损耗能量随最大应力幅值的提高而增大,在相同最大应力幅值处混凝土强度越高,单位体积耗能越小.对结果非线性回归建立了素混凝土材料单位体积耗能与最大应力幅值及混凝土强度之间的关系式,在理论上为混凝土材料阻尼的计算提出了新的思路及方法,也为进一步准确分析其结构动力性能、进行安全经济合理的抗震设计打下基础.

A new method is presented to compute material damping of plain concrete. Based on the study of relation between material damping and stress amplitude by Lazan, the area of hysteresis loop of plain concrete components under axial cycle load is calculated with Hognestad constitution model and Karsan-Jirsa loading-unloading law by OpenSEES system, thus the energy dissipation of plain eonerete is obtained. It is indicated that trait energy dissipation of plain concrete increases with the inerease of maximum stress amplitude and decreases with the inerease of concrete strength. The relation formula of energy dissipation of plain concrete with maximum stress amplitude and eonerete strength is established through nonlinear regression, which will be helpful in material behavior study of eonerete and dynamic response analysis of concrete structures.