| Sheet hydroforming technology is an advanced metal flexible manufacturing technology which liquid is used as transmission media to form the parts. Compared with the traditional deep drawing,it has some advantages such as short manufacturing cycle, low deformation, formed parts has high precision and good surface quality. Drawing with double side pressure is one of the sheet hydroforming technology which exerts liquid pressure on the upper sheet surface acoordinating with the chamber pressure. The upper pressure can offset the pre-bulging which is suited for forming complex shape parts such as cylindrical and semi-ball cup.In this paper, aimed at forming the chamfered cup using drawing with double side pressure, process parameters of forming chamfered cup was investigated by numerical simulation and experiments, the best process parameters were summarized.The critical condition of rupture in forming process was gived by analyzing the deformation mechanism, and the parameters inducing rupture were also analyzed.The forming process was simulated by software ETA/Dynaform5.6,the effect on the thickness distribution of parameters such as oblique angle, the upper pressure, double side pressure and the friction coefficient were investigated, furthermore, the trend of plastic deformation and movement was analyzed, the typical points the stress and strain distribution of the typical points was respectively investigated.Experiment recearch was performed containing analyzing the thickness and strain disribution, in order to compare the effect of the upper pressure and double side pressure on forming process, the best parameter was obtained. The plastic instabiligy behavior and the failure types were analyzed and the effective solutions were made. |
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