Numerical and experimental determination of process parameters in double-sided sheet hydro forming

Double Sided Hydroforming (DSHF) process, which is used in the shaping of sheet metals (ogive, oval, elliptical, etc.) that cannot be shaped by hydromechanical deep drawing (HDD), was investigated by experimental and numerical methods in this dissertation. AA 5754 aluminum alloy, which is used extensively in the automotive industry, and AISI 304 stainless steel, which is frequently used in the food and automotive industry, were preferred as test materials. In order for the process to be applied experimentally, the necessary systems have been integrated into the hydroforming press in the Hydroforming Laboratory to perform the ÇTHŞ. For the experimental implementation of the DSHF, the necessary components were integrated into the hydroforming press, which has the hydromechanical deep drawing capability, in the Hydroforming Laboratory in KTUN. In order to examine the effect of DSHF on formability according to HDD in different workpieces geometries, with cylindrical and axisymmetric industrial parts were manufactured. The finite element model of the DSHF and HDD processes was created using the Ls-Dyna SE program. Optimum forming pressure, counterpressure and blank holder force (loading profiles) were determined numerically with Fuzzy Logic Control Algorithm (FLCA), which works adaptively with finite element analyses. The uncertainties in the shaping of non-cylindrical axisymmetric parts are greater than that of cylindrical axisymmetric parts. In addition to Type-1 FLCAs used in the literature for adaptive control of hydroforming, Type-2 BMKA, which can provide better results in modelling uncertainties, was also used. The numerically determined optimum loading profiles were also confirmed by experiments. It has been demonstrated numerically and experimentally that the wrinkling errors that occur when produced with HDD in the axially symmetrical industrial part produced by DSHF are completely eliminated. Therefore, there is no need for a second operation in terms of manufacturing in order to correct the wrinkling errors in the industrial parts produced with HDD. Thus, the technical and financial advantages of the DSHF process have been revealed. The methods developed in DSHF for determining the optimum loading profiles were successfully applied for both cylindrical and industrial parts with a different geometry, and the developed methods were generalized independent of material, thickness and geometric shape.