应变上限递增的混凝土高压应变循环受力试验

Compression Experiment of Concrete Under Cyclic Loading with Gradually Increased Strain Upper Limit of Large Strain Amplitude

为了建立考虑高应变低周疲劳性能的混凝土受压本构模型,利用全数字化电液伺服式试验机及其位移控制加卸载功能,在已经完成的混凝土棱柱体等应变幅多次重复受压试验(最大应变以不同幅度超过ε0,0ε为与峰值应力对应的应变)的基础上,进一步完成了压应变上限逐步加大的混凝土棱柱体多次重复加卸载试验,获得了其独特的低周疲劳特征及加卸载应力-应变规律.结果表明,有必要根据实测结果对以往假定的卸载-再加载本构模型作出重要调整.

In order to formulate the compressive stress-strain model of concrete in which the behavior of low cycle fatigue under large strain is considered, two fatigue tests of concrete prisms under axial compression in which the upper limit of the strain amplitude gradually increased are carried out by the displacement-controlled loading function of the numeric electro-hydraulic servo test machine. These test are based on the several fatigue tests of concrete prisms under axial compression, in which the specified large upper limit strain exceeds ε0 at various levels,ε0 is the strain when the stress reaches the peak. The special characteristics of low cycle fatigue and relation between the loading and unloading stressstrain of concrete are obtained. Above rule shows that it is necessary to modify the former assumed unloading-reloading constitutive according to the actually measured result.