Sheet Metal Hydroforming Tryout Through Numerical And Experimental Validation

Though sheet hydroforming has often been considered a good opportunity for industrial applications related to niche and medium-low volume productions, this technology has not yet found a specific application context as it is for tubes hydroforming (1). Thanks to its extensive application to industrial cases, the latter has defined, through appropriate experimental validations, “best practice” rules for process design (2) and for its tryout (3, 4 and 5). Though not as exploited, sheet hydroforming has many advantages that meet industrial needs very well, such as: formability improvement, good surface quality, higher dimensional accuracy, springback reduction (6). In this paper proper metal forming numerical models and experimental analysis have been developed in order to analyze the feasibility of an industrial test case process design using this non conventional technology. Two different initial blank shapes, two different blank holder load paths (that is made up of twelve sectors) and, finally, two different fluid pressure load paths have been tested. There is clearly a good correlation among numerical and experimental results and also a robust response of the designed mechanical equipment which is able to follow, with a good accuracy, the assigned process characteristics (fluid pressure, blank holder force distribution, etc.). Different process conditions have been numerically and experimentally tested, not reaching, at this stage, the feasibility or, it would be better to say, the “hydroformability” of the product.