混凝土单轴直接拉伸受力分析

Stress analysis of concrete in uniaxial direct tension

对3种直接拉伸试验方式(内埋式、外夹式和粘贴式)下混凝土试件各点的应力分布状况进行了有限元数值分析,对获得混凝土单轴直接拉伸应力-应变全曲线所需的条件进行了探讨,并对试件在两端粘贴受力方式下辅以刚性架装置后刚性架拉杆刚度、位置对试件受力的影响进行了研究.结果表明:两端粘贴加载方式可使试件各点应力分布更加均匀,应力集中程度较低;减小刚性架的高度、增大刚性架的截面积有利于获得完整的应力-应变全曲线.

Stress distribution at different points of concrete specimens was analyzed with FEM in 3 kinds of direct tension, i.e. embedded bar manner, steel plates connecting manner, and glued plated grip manner, and the conditions for obtaining the complete stress-strain curve of concrete in uniaxial direct tension were discussed. Moreover, the mechanical behaviors of concrete specimens in glued plated grip manner which was supported by a stiff frame were analyzed, with the effects of stiffness and location of the stiff frame taken into account. The results show that the glued plated grip manner makes the stress distribution in concrete more uniform, and that decreasing the height and increasing the cross section of the stiff frame make it easy for obtaining the complete stress-strain curve.