Forming response of AA5052-H32 sheet deformed using a shock tube

激波管变形AA5052-H32板材的成形性（英文）

The effect of bending pre-strain and pressure on the forming behavior of AA5052-H32 sheets has been studied using a shock tube. Various forming parameters like dome height, effective strain and stress distribution, hardness, and grain size evolution have been measured. Circular grids are printed on the sheets and Hill’s 1948 yield criterion is used to calculate the effective strain distribution. The effective stress distribution is calculated by using the Hollomon’s power law. The strain evolution during the forming process is monitored by mounting a strain rosette at the mid location of the sheet. The strain-time graph confirms the sharp rise in the peak strain and it increases significantly at higher pressure. The variation in the forming parameters asserts that the material stretches uniformly without strain localization. The optical microstructures also depict that the equiaxed grains are stretched and elongated after the shock deformation. This analysis confirms that the forming behavior of the material is dependent both on the degree of pre-strain and the change in pressure.

采用激波管研究弯曲预应变和压力对AA5052-H32板材成形行为的影响。测量变形拱形高度、有效应变和应力分布、硬度和晶粒尺寸演变等各种成形参数。在板材上印制圆形网格,并用Hill’s 1948屈服准则计算有效应变分布,通过Hollomon幂次定律计算有效应力分布。在板材的中间位置安装一应变片以监测成形过程中应变的演化。应变-时间图证实峰值应变的急剧上升,并在较高的压力下显著增加。成形参数的变化证实材料在没有应变局部化的情况下被均匀拉伸。光学显微组织显示等轴晶在冲击变形后被延展和拉长。因此,材料的成形行为既取决于预应变的大小,也取决于压力的变化。