7B04铝合金带筋构件蠕变时效成形数值模拟与试验

Numerical simulation and experiment on creep age forming for 7B04 aluminium alloy stiffened component

基于7B04铝合金165℃单轴拉伸蠕变试验数据,拟合得到时间硬化本构方程,利用有限元软件ABAQUS对带筋构件的蠕变时效成形过程进行数值模拟,分析筋条的变形规律,并进行验证试验和性能研究。结果表明:筋条的塑性变形有效减小蒙皮的回弹,和蠕变变形共同决定构件外形;数值模拟与试验结果吻合较好,构件95%外形区域的绝对偏差值≤0.50 mm;构件的筋条强度高于蒙皮强度,与无应力时效相比,构件的伸长率降低,电导率升高;应力松弛试样的性能和筋条的性能相近,可以进行等效表征。

Time hardening constitutive equation for 7B04 aluminium alloy was determined from uniaxial tensile creep data at 165 ℃. Numerical simulation of creep age forming for stiffened component was carried out and the deformation behavior of stiffener was analyzed by finite element software ABAQUS. Then verification experiment and material performance were studied. The results show that plastic de- formation of stiffener can reduce springback efficiently and determine outer contour in company with creep strain. Close agreement between calculated and experimental value for the formed shape is achieved. The absolute deviations of 95% area are less than 0. 50 mm. The strength of stiffener is higher than that of skin on the component. The elongation of formed part decreases compared with stress-free aged sample, while the conductance increases. The properties of stress relaxation specimen are close to that of stiffener, which shows that the equivalent token method is feasible.