Optimization of material of flexure spring by finite element analysis

Abstract

Abstract Flexure spring is thin metallic disc used to allow relative motion by bending between the piston and the fixed support in compressor body. The flexure spring deforms by the force applied by piston and come back to its original position. As spiral arms cut from its surface, flexing takes place. The main object of this article is to optimize the spring material to enhance the service life of spring. The present article analyzes five different copper based alloys as these materials are having elasticity property. Initially the model was prepared in Catia software. The Finite Element Analysis (FEA) was carried out by applying boundary conditions. As the total displacement of piston is 10 mm so force is applied at the central hole in such a way that the spring will deform for 5 mm from mean position. Due to applied load stresses will develop in the flexure. The equivalent stress was observed for chosen materials. The equivalent stresses were compared with permissible stress for that material by considering factor of safety (FoS). The cold drawn copper and the Beryllium copper UNS C (TH02) found suitable for flexure spring having the stress within permissible limit. As stiffness is also important property for spring. The deformation was observed in FEA for these two materials by applying 1 N force. The stiffness was calculated. The material was selected which will give maximum stiffness. It was found that the Beryllium copper UNS C (TH02) shows the maximum stiffness.