Research On The Cylindrical Cups With Concave Bottom Forming By Hydrodynamic Deep Drawing With Inverse Bulging Base On Numerical Simulation

With the development of aviation, aerospace, and auto parts manufacturing industry, the important means of realizing pollution-free and lightweight is using aluminum alloy, magnesium alloy and titanium alloy. Therefore, lightweight sheet can be widely used, such as aluminum alloy and titanium alloy atc. However, the sheet metal of lightweight alloy have low plastic, poorer forming performance, small hardening exponent and heterosexual index, and this became the bottleneck in processing industries, especially difficult to forming of one step deep drawing for large height-diameter ratio of parts forming.Hydrodynamic deep drawing (HDD) is a kind of advanced flexible sheet metal forming method. To satisfy the alloy forming need of low plasticity materials and large height-diameter ratio of aero space, research on 5A06 alloy concave cup's hydrodynamic deep drawing with inverse bulging with numerical simulation. By employing the dynamic explicit analytical software EAT/Dyna-form 5.6 base on LS-DYNA3D and according to the forming process, at the bottom of the concave shape is the key of parts forming. The results indicated that the reasonable match among the bulging pressure and liquid chamber pressure could reduce the tensile stress, restrain the serious thinning at the bottom of the concave cups and increase the drawing limitation of aluminum alloy concave bottom cup.To meet the forming need of large height-diameter ratio aluminum alloy sheet, a new forming process is proposed, that is hydrodynamic deep drawing (HDD) with radial hydraulic pressure.Using numerical simulation method, this paper discusses and analyses changes of load curves of chamber pressure and radial to influence of minimum thickness of concave bottom parts, and the minimum thickness of the final forming of the part use as evaluation standard. Simulation results showed that the rational matching of radial and liquid room loading paths, can significantly control crack and wrinkling.thus improve parts thickness variation distribution uniformity, remarkably increases the forming limitation of alloy large height-diameter ratio concave bottom cylindrical cup.Based on the experimental method, respectively research deep drawing coefficient 2.3 the concave bottom cylindrical parts forming law. Comparative simulation results, analysis of the rupture form and discuss the influence on concave bottom cylindrical parts forming from initial bulge pressure, chamber pressure and radial hydraulic pressure. Through the experiment verified that the hydrodynamic deep drawing technology quality forming a high-lever concave bottom piece of feasibility and achieving high quality forming parts.