TY - JOUR ID - 904 TI - Meshless analysis of backward extrusion by natural element method JO - Iranian Journal of Science and Technology Transactions of Mechanical Engineering JA - IJSTM LA - en SN - 2228-6187 Y1 - 2011 PY - 2011 VL - 35 IS - 2 SP - 167 EP - 180 KW - Metal Forming KW - backward extrusion KW - natural element method KW - meshless methods KW - Finite element method DO - 10.22099/ijstm.2011.904 N2 - In this paper, a computational technique is presented based on the natural element method (NEM) for large plastic deformation simulation of the metal forming problems. NEM is a numerical technique in the field of computational mechanics and can be considered as a meshless method. The selected process is backward extrusion for circular shape hollow components from round billets. The punch stroke value is divided into sub-steps, whereas a new set of nodes become active at the end of each sub-step of deformation. Solutions are obtained for different area reductions under friction condition. Hollman-Ludwik law is selected to explain the material behavior after the yielding point. The experiments are carried out with fully annealed commercial aluminum alloy billets at room temperature, using various punch sizes. A set of die and punches are designed and constructed for experimental works. The validity of the proposed method is verified by comparing the results from deformed geometry, contours of equivalent strain and forming loads with those obtained from finite element simulation and experimental measurements. It is concluded that the results obtained by NEM are in good agreement with those from FEM and experiments and therefore, the meshless natural element method is capable of handling large plastic deformation.            UR - https://ijstm.shirazu.ac.ir/article_904.html L1 - https://ijstm.shirazu.ac.ir/article_904_95ab61c422a2aeedac549bbb139bcce6.pdf ER -