高温下薄壁圆筒拉伸试样的应力-应变关系研究

采用试验和有限元相结合的方法对不同温度下薄壁圆筒拉伸试样的颈缩问题进行了研究。试验结果表明，薄壁圆筒试样颈缩时，其内外径均有变化，并且外径的变化比内径的变化要大。采用有限元法对薄壁圆管拉伸试件进行应力应变分析，对最小颈缩面上的应力分布的分析表明：沿着薄壁圆筒的内壁到外壁的径向方向，应力呈减小的趋势，这与试验中薄壁圆筒首先从内壁开始破坏的结果是相符合的。比较试验所得的不同温度下的拉伸曲线与采用计算机模拟的方法得到不同温度下的应力应变关系，二者符合性较好，得出了试样在特定温度下的真实应力-应变曲线。

On the study of stress-strain of thin-walled cylinder tensile specimens at high temperature

The necking of the thin-walled cylinder specimens at different temperature have been studied for isotropic material using experimental and finite element(FE) methods.The result of the experiment shows that the inner radius and the outer radius are changing with the neck of the thin-walled cylinder specimen.And the change of the outer radius is larger than that of the inner radius.The FE method is introduced to analysis the stress distribution of the specimen.The FE result shows that stress is reducing along radius direction from inside to outside.It accords with the result of the experiment.And the FE simulation is carried out on necking of the thin-walled cylinder on the based of the experiment displacement-load curve furthermore.The simulation curve is obtained through FE method.We compare two curves and modify the differences between them until the two curves are as similar as possible.Then the true stress-strain curve of the thin-walled cylinder at different temperature is obtained.