材料模型对1Cr18Ni9Ti管材拉伸有限元仿真的影响

为研究材料模型对有限元模拟1Cr18Ni9Ti管拉伸的影响，将管材单向拉伸试验获取的真实应力应变曲线分别拟合成线性硬化和指数硬化材料模型，并用于有限元模拟。经对比分析认为，采用真实应力应变模型的分析结果与实验结果吻合良好，并能正确显示出颈缩发生时刻和颈缩形状；采用指数硬化模型的有限元模拟结果接近真实应力应变模型，颈缩区应力应变分布略显分散；采用线性硬化模型的有限元模拟结果未能显示实际管拉伸后期的局部颈缩形状。

Effects of Material Models on Finite Element Simulation for Uniaxial Tension of 1Cr18Ni9Ti Tube

To explore the effects of material models on finite element simulation for uniaxial tension of 1Crl8Ni9Ti tube, true stress-strain curve obtained by uniaxial tensile test is fitted to linear hardening and exponent hardening models which are utilized in finite element simulation. It is numerically revealed that true stress-strain model shows good agreements with experimental data, which correctly indicates the time and shape when necking occurs; the simulated results gained by exponent hardening model are close to that achieved by true stress-strain model, but the stress-strain distribution in the necking zone is slightly dispersive; compared with the models mentioned above, linear hardening model fails to correctly reflect the necking shape in the tensile later stage.