Machining fixture layout optimization using FEM and evolutionary techniques

Design of fixture configuration (layout) is a procedure to establish the workpiece fixture contact through positioning of clamps and locating elements such that the workpiece elastic deformation is minimized. This work is done based on the assumption that the workpiece is an elastic body. Since the fixture layout influences the dimensional and form accuracy of the workpiece during the machining process, the fixture layout has to be optimized to minimize the workpiece deformation. In this paper, the workpiece deformation is modeled using finite element method (FEM), for the problem of fixture layout optimization problems with the objective of minimizing the dimensional and form errors. This paper presents a fixture layout optimization method that uses genetic algorithm (GA) and ant colony algorithm (ACA) separately. In this paper, three different number of node systems are defined on the same workpiece geometry to find the consistency in the performance of GA and ACA. The optimal solution, i.e., the most minimum value among the entire possible layout is determined separately for all three different number of node systems. The solution obtained for each node system using GA and ACA is compared with their respective optimal solution separately and ACA reports faster and accurate solutions.