Finite Element Analysis and Optimization of Machine Fixture

Abstract

During machining operation, fixtures are used to locate and constrain a work piece. In any manufacturing operation, a certain amount of deformation will occur in the work piece due to clamping and machining forces. So the dimensional and form errors will occur in the work piece. A good fixture design minimizes work piece geometric and machining errors by limiting the work piece elastic deformation. An ideal fixture design exhibits minimal deformation while machining and it consists of optimal fixture layout, optimum clamping forces and optimum number of fixturing elements such as locators and clamps. Hence, in this research work, the machining fixture layout, clamping forces and number of fixturing elements optimization problems are considered with an objective of minimizing the work piece elastic deformation caused during machining. In this machining fixture layout optimization problem, the work piece is treated as elastic model and fixture elements are treated as rigid to predict the work piece elastic deformation, which influences the dimensional and form errors of the work piece. In this research work, Finite element solver ANSYS has been used to determine the work piece elastic deformation caused due to machining and clamping forces.