Numerical and Experimental Investigation of Die Design in Expansion Forming Process by Soundless Chemical Demolition Agents

Abstract

This study designed an optimal die using finite element analysis (FEA) and experimental tests to facilitate the forming process with soundless chemical demolition agents (SCDAs). However, the expansion pressure generated by the SCDAs caused deformation and cracking in the die. Consequently, the finite element (FE) technique was employed to analyze and design an optimal die. The Johnson-Cook plasticity and damage model was utilized to simulate the behavior of the deformable die. The simulation results indicated that a maximum stress of 850 MPa was generated in the die; therefore, CK45 steel was selected as the die material. Additionally, the optimal inner diameter and thickness of the die were determined to be 105 mm and 25 mm, respectively. Experimental results revealed that the evaporation of water due to hydration within the die produced sudden pressure, leading to the tearing of the sheet. To prevent the tearing caused by water vapor, a grooved washer was designed and installed at the end of the die. After manufacturing the die with the optimal diameter and thickness, the forming process was successfully executed using SCDA, resulting in no defects in either the die or the sheet.