Complex Sheet Metal Hydroforming Process Research And Finite Element Analysis

Sheet metal hydroforming is advanced technology and is developed and applied in recent years, it is mainly applied in car making, aviation, kitchen utensils and other fields. Sheet metal hydroforming has characters such as low die cost , short manufacturing cycle and high form limit. The parts processed by it have high precision and good surface quality compared with traditional technology, so it can process sheet parts with complex shape and high precision,Sheet metal hydroforming in pairs is new technology that is developed on base of single sheet metal hydroforming. It not only has the advantages of hydroforming but also increases the efficiency and cuts down devices, so the processing cost is reduced. Sheet metal hydroforming in pairs is very suitable to process the container such as motorbike tank that is made by welding upper cover and lower cover.The motorbike tank is a container part that is made by welding upper cover and lower cover. It has complicated surface and high drawing ratio, so it is suitable for sheet metal hydroforming in pairs. If the conditional technology is used , it needs two sets of die and two hydraulic presses, this will increase die cost and processing cost. Considering these cases , this paper puts forward a process of sheet metal hydroforming in pairs in making motorbike oilbox and analyses it by finite element method. On this base, the device of sheet metal hydroforming in pairs is designed and this device is simple and reliable. If putting this device on double-action hydraulic press, it can form the motorbike tank.In this paper, the hydraulic bulge test is done to small size part and analysed it by finite element method. When the result of finite element simulation is consistent with experiment, we can say the finite element method is feasible . In this paper, sheet metal hydroforming in pairs ofmotorbike tank is analysed by the soft LS-DYNA and the part forming is studied in different conditions. From the results, the distributing of stress and strain and the change of sheet thickness are observed , the place of crack and crinkle is forecasted , the match of blank holder force and hydraulic press is optimized and all of these can be a referential method for annlysing sheet metal hydroforming in pairs.