Numerical and Ezperimental Investigation on Mazimum Sheet Hydroforming Depth
Sheet metal hydroforming has gained increasing interest around the world in the automotive and aerospace industries. This non conventional metal forming process has many advantages that meet the industrial production needs in reality very well,such as: improvement of the sheet formability,good surface quality,higher dimensional accuracy,reduction of springback amount compared with the conventional processes1 Furthermore,the process chain could be simplified with considerable costs savings2,3. In this paper the authors aim to analyze,numerically and experimentally,the maximum hydroforming depth for different geometries,process parameters and thicknesses. The analyzed material is an industrial steel,FeP04,with thicknesses of 0. 7 mm and 1 mm. For the numerical investigation proper numerical models have been implemented and an explicit code has been used. For the experimental campaign a traditional hydraulic press has been used in combination with a special tooling defined hydroforming cell4,5. Three different geometries (MOD1,MOD2 and MOD5) have been taken into account; for each one of them two different steel thicknesses (0. 7 mm and 1 mm) ,two different fluid pressures and two different distributions of the blankholder force have been analyzed. For each product (MOD1,MOD2 and MOD5) a 2k fractional factorial plan has been implemented. The monitored response is the maximum hydroforming depth reached before rupture. In this paper the authors analyze the influences on the maximum hydroforming depth only of the chosen material and of the process parameters,without taking into account the geometry of the single products. Through the numerical and experimental analysis it has been possible to verify,for the maximum hydroforming depth,the influences of the blankholder force and of the material thickness are bigger than the one of the fluid pressure. Because of the analysis of the observed ruptures during the experimental phase,the authors have decided to design another experimental plan to study the influence of the pre-bulging on the maximum hydroforming depth. The final result is that the pre-bulging increase the feasibility of the process for MODI and MODS but not for MOD2,due to its particular geometry.
hydroforming depth sheet metal thickness fluid pressure blankholder force pre-bulging
PAPADIA Gabriele DEL PRETE Antonio ANGLANI Alfredo
Scuola Superiore ISUFI,University of Salento,Italy Department of Engineering Innovation,University of Salento,Italy
国际会议
2009 International Symposium on Automobile Steel(2009年汽车用钢生产及应用技术国际研讨会)
大连
英文
350-356
2009-09-06（万方平台首次上网日期，不代表论文的发表时间）