نوع مقاله : مکانیک ضربه
نویسندگان
1 دانشجوی دکتری، دانشکده فنی و مهندسی، دانشگاه امام حسین(ع)، تهران، ایران
2 استاد، گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه امام حسین (ع)، تهران، ایران
3 نوینده مسئول: گروه مهندسی مکانیک، دانشکده مهندسی مکانیک، دانشگاه جامع امام حسین ع، تهران، ایران
4 گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه جامع امام حسین (ع)
5 استادیار، دانشکده مهندسی مکانیک، دانشگاه ایوانکی، ایوانکی، ایران.
چکیده
تازه های تحقیق
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
In the present research, the experimental investigation of the female die forming of metallic plates with and without the use of venting hole in the central part of the plate has been performed. In order to apply the load to the specimen, repeated underwater explosive loading was used, so that in the 1st loading, the mass of the explosive charge was 4 gr and in the subsequent loadings, 8 grs were used. The results of the research showed that in the process of female die forming with venting hole, a protrusion or discontinuity is created in the central part, which leads to an increase of 28, 73 and 90% of the maximum thinning along the radial length of the plate in the 2nd, 3rd and 4th loadings in comparison to the 1st loading. Also, for the thinning in the center in the same situation, an increase of 27% and a decrease of 8% and 6% were observed, which was an unusual behavior caused by the presence of the venting hole. In this case, the filling rate of the specimen was 24%. This is despite the fact that in the process of female die forming without venting hole, the filling rate, maximum thinning and thinning in the center increased by 30%, increased by 6% and decreased by 10%, respectively. One of the important points is that the maximum amount of thinning in the primary bending region is lower compared to the center of the plate when using female die forming without venting hole, which is the opposite result obtained in the die forming with venting hole, so that in that case, the maximum thinning in the center of the area was higher than the region with initial bending. Therefore, it is very efficient to use the idea of female die forming without venting hole for sheet metal forming under repeated underwater explosive loading.
کلیدواژهها [English]