Application of optimal design and control strategies to the forming of thin walled metallic components

Modelling of the post-localization behaviour in tube hydroforming of low carbon steels

“…However, the plastic instability prediction and tracking is an open problem for some carbon steels. Another key point concerns the automatic determination of an initial parameter set for a successful forming operation [8,9]. Choosing the appropriate material and improving both tube and die design require the process limits to be well known.…”

Analysis on critical conditions of sidewall wrinkling for hydroforming of thin-walled Tee-joint

“…Numerous investigations on Tee-joints hydroforming have been mainly concentrated on loading paths prediction on purpose of thickness uniformity control [8,9]. The following are some of the attempts to develop the faster or more systematic approaches to find the loading curve versus process parameters that minimize the thickness variations, including genetic algorithm [10], trial and error FEA Simulation approach [11], optimal design approach [12], adaptive approach [13,14], fuzzy load control algorithm [15] and neural network analysis method [16,17]. In the above optimization methods, on the premise of wrinkling free, through adjusting loading paths, higher branch height and more uniform thickness distribution were achieved.…”

Numerical simulation of sheet hydroforming taking into account analytical pressure and fluid flow

“…In order to control the hydroforming of tubes to avoid failure, bursting and buckling, various authors have proposed strategies to determine the limiting axial loads to apply to pistons or counter pistons in order to prevent risks of buckling and failure (Gelin and Labergere, 2002;Gelin et al, 2007). The advantages of controlling precisely the displacements of the pistons was clearly demonstrated (Gelin and Labergere, 2002) where it is shown that the loading curve vs. time and pressure has a strong effect on the possibility to get the final component without defects.…”

“…The advantages of controlling precisely the displacements of the pistons was clearly demonstrated (Gelin and Labergere, 2002) where it is shown that the loading curve vs. time and pressure has a strong effect on the possibility to get the final component without defects. An example of hydroforming liner for storage illustrates the usefulness to build the pressure curve with an optimization method (Gelin et al, 2006).…”