In this paper, the Drawing process of multilayer Sheet metal through a wedge-shaped die has been analyzed using stream function and upper bound method. Typically, a sandwich Sheet contains three layers of metal, where the outer layers are of the same thickness and material and different from those of the inner layer. In this study, a new deformation model has been introduced in which inlet and outlet shear boundaries are considered flexible and the effect of work hardening of Sheet layer materials has been considered. According to the suggested stream function, velocity field, strain rates and powers have been calculated. The optimized geometry of the deformation zone and the required Drawing force have been determined depending on the process conditions. Analytical results including the Drawing force and thickness of the Sheets in the outlet of the die have been compared with the finite element (FE) results. The FE results have good congruence with the analytical ones. Finally, the effects of friction factor and reduction in thickness have been investigated on the Drawing force and the optimum die angle.

Deep Drawing process is one of the most applicable methods in producing industrial parts. In this process, the initial blank deforms to final product using a rigid punch and die. In this investigation, the effect of deep Drawing process parameters of brass/steel laminated Sheet composites on required forming force has been investigated. The process simulated using finite element method (FEM) and then validated by using experimental results. Afterward, the effect of process parameters including friction coefficient between punch and Sheet (punch friction), friction coefficient between die and Sheet (die friction), blank holder force and the initial blank diameter all in three different levels investigated using design of experiments (DOE) by Taguchi method. Based on four selected parameters in three levels, experiments performed by Taguchi L9 orthogonal array and then the maximum punch force of each experiment was obtained using validated FE model. Signal to noise (S/N) analysis demonstrated that the die friction is the most important parameter in deep Drawing of brass/steel laminated Sheet that by its reduction, the maximum punch force decreases. Also, analysis of variance (ANOVA) results illustrated that the die friction and initial blank diameter are involved 53.1 and 43.4% of contribution on maximum punch force, respectively.

In this paper, a FEM-based Taguchi method is used to determine the effects of forming parameters on the quality of part formability in the process of hydrodynamic deep Drawing assisted by radial pressure. Four important forming parameters, fluid pressure, friction coefficient at blank/punch interface, die entrance radius and the amount of gap (g) between die rim block and blank holder are considered in this investigation. In order to have more comprehensive study, three different workpieces are used as the case studies. Three-dimensional FE models are developed for simulating the forming process. After experimental validation, these models are used for performing the set of experiments designed by Taguchi’s L-9 orthogonal array. The signal-to-noise (S/N) ratio and the analysis of variance (ANOVA) techniques are used to calculate the contributions of each of the mentioned parameters to the output characteristic. The results indicate that fluid pressure and friction coefficient are the most influential parameters. Also, die entrance radius and the amount of gap (g) have considerable effect on the part formability. The obtained results may provide useful guidance on determining forming parameters.

Hydro-mechanical deep Drawing (HDD) is one of the most convenient processes in which a Sheet metal is drawn against a counter pressure rather than a rigid die in conventional stampings. This process has been increasingly used to produce aerospace and automotive components. More recently, aerospace industry is demanding new materials with capability to produce high strength to weight ratio products. Moreover on hydro-mechanical deep Drawing investigations, numerical considerations are used in order to design the process parameters to produce a cost-effective with high quality components. While, this process has not been investigated for superalloy cups. Nickle-based superalloy Sheet metals are more prominent in aviation and spaceflight industries. In this paper, numerical simulation of hydro-mechanical deep Drawing for Haynes230 nickle based superalloy has been investigated. Moreover, the pressure paths which yield rupture and wrinkling have been realized. Furthermore, differences between applying uniform and gradual pressure into the pressure chamber have been detected to nominate a pressure path for successfully producing a superalloy cup made by HDD. Subsequent to that, chamber pressure against punch travel curves was depicted. For this investigation, 3-D finite element method was employed and the results obtained from numerical simulation were validated using experimental data already available in the literature.

In most of Sheet forming processes, production of the final parts with minimum thickness variation and low required force is important. In this research, minimization of the Sheet thinning and forming force in the hydraulic deep Drawing process was studied. Firstly, the process was simulated using the finite element method (FEM) and the simulation model was verified compared to experimental results. Then the Sheet thinning ratio and punch force were modeled as objective functions using the response surface methodology (RSM). In this model, process parameters including punch nose radius, die entrance radius and maximum fluid pressure were the input variables. Required experiments for the RSM were designed using the central composite design (CCD) method and performed by FEM. Finally, optimum point of the parameters was obtained by multi-objective optimization of the objective functions using the desirability function method based on response surface model and then evaluated. In addition, optimum ranges of the parameters were determined using overlying contour plots. Results showed that the response surface models had good adequacy. According to this model, increasing of the punch nose radius and die entrance radius lead to decreasing of thinning ratio and increasing the maximum punch force. Also the maximum punch force increases by increasing the maximum fluid pressure. Optimization results represent reduction of the thinning ratio almost 10% compared with conventional results.