论文部分内容阅读
运用有限元软件ABAQUS建立压印强化残余应力场的三维有限元模型,模拟计算压印强化过程中2B25-T351铝合金构件的三维残余应力场分布,模拟结果表明,压印痕底部残余应力沿厚度方向呈梯度分布,与表面距离越远,压应力水平越小。孔周围的残余应力分布比较集中,压印痕端头附近,孔边为相对均匀的残余压应力,其他位置为自平衡的残余拉应力;使用X射线衍射应力分析技术测量实际试样的残余应力,结果表明,实验测量值与有限元模拟值吻合较好;对压印强化前后试样进行疲劳性能试验,结果表明,压印强化在试件表面引入残余压应力,可降低裂纹萌生的几率及裂纹扩展的速率,压印强化后材料的疲劳寿命提高了近1.5倍。
The three-dimensional finite element model of imprint strengthening residual stress field was established by using finite element software ABAQUS to simulate the three-dimensional residual stress field distribution of 2B25-T351 aluminum alloy during imprint strengthening. The simulation results show that the residual stress at the bottom of imprint marks increases along the thickness direction Gradient distribution, the distance from the surface, the smaller the level of compressive stress. The distribution of residual stress around the hole is relatively concentrated. The residual compressive stress near the edge of the embossed mark is relatively uniform and the rest is self-balanced residual tensile stress. The residual stress of the actual sample is measured by X-ray diffraction stress analysis, The experimental results show that the measured values are in good agreement with the finite element simulation results. The fatigue tests of the specimens before and after stamping strengthen show that the compressive strengthening can introduce residual compressive stress on the specimen surface to reduce the probability of crack initiation and cracks The rate of expansion, the fatigue life of the material after stamping enhanced by nearly 1.5 times.