混凝土二维本构关系试验研究

Experimental study on 2-D constitutive relationship for concrete

本文采用Instron-8506四立柱液压伺服试验机对混凝土二维本构关系进行了系统的试验研究。在应变控制加载的条件下测得了混凝土板式试件在二轴压-压区和拉-压区的双轴应力应变全曲线。分析了试件的破坏特点,讨论了不同应变组合条件下试件的破坏模式。提取全曲线的特征参数,建立了应力空间和应变空间的强度包络线,并与经典试验结果进行了对比。研究表明双轴应变比例控制加载条件下可以测得混凝土板式试件的二轴应力应变全曲线,所得曲线具有一定的精度和可信性。本文得到的应力应变全曲线和包络线为多轴本构关系的研究以及复杂结构设计提供了依据。

Systematic experimental studies were carried out on an Instron-8506 hydraulic servo test machine to investigate the 2-D constitutive law for plain concrete. Biaxial stress-strain curves of biaxial compression and compression-tension were obtained under biaxial strain-controlled loading condition. Based on observations of specimens, failure modes in different loading combinations were discussed. The ultimate strength envelopes in both stress space and strain space were developed by analysis of the experimental data and compared with the results of some classical experiments. It is concluded that biaxial full process strain-stress curves of concrete specimen can be obtained under biaxial proportional strain-controlled loading condition. This study laid a solid foundation for the further research on multi-axial constitutive laws of concrete.