低屈服钢拉伸试验与数值研究

Tensile Test and Numerical Study of Low Yield Steel

为了了解低屈服钢的拉伸性能,开展拉伸试验并进行数值研究:采用圆棒试件进行单轴拉伸试验,分析试件的力-位移曲线、延展性以及断裂模式等;基于幂强化法和加权平均法计算材料颈缩后的真实应力-应变数据;采用扩展有限元方法对圆棒试件的拉伸、颈缩以及断裂过程进行数值模拟。通过与试验数据的对比发现:加权平均法可以得到与实际相吻合的颈缩后的真实应力-应变数据;扩展有限元方法可以对低屈服钢的拉伸、颈缩与断裂过程进行有效的仿真。

The mechanical behavior of low yield steel under tensile loading was investigated by test and numerical analysis. First of all, the uniaxial tensile test was carried out with the standard bar specimens, and the force- displacement curve, ductility and fracture mode were analyzed. Secondly, the real stress-strain data of material necking were calculated by the power law and the weighted average method respectively. Finally, the extended finite element method was adopted to simulate the tests including the deformation, necking and the fracture behavior of the specimen. By comparing with the experimental data, the real stress-strain data after necking obtained by the weighted average method is consistent with the actual test, which shows that the extended finite element method would be served as an efficient tool to simulate and predict the whole process of the uniaxial tensile behavior of low yield steel.