Optimum Design Of Heavy Machinery BeamsUsing Shape, Material And ManufacturingMethod Selections With Fuzzy Satisfaction Goals

Abstract

The main purpose of this study is to present the results of a project for optimum design of a large paper machinery beam needed to transmit reliably the load cycle forces. The following methods are used. First, the work cycle loads are obtained from production process data. Then FEM is used to optimize the structure with a mass minimization goal and with constraints on deflections, stresses and buckling. An analytical optimization method is used in which the goals are formulated in a fuzzy way to maximize the satisfaction of the customer on the cost of the beam material, the cost of the weld manufacturing and on fatigue life. Constraints are included on stress, deflection and buckling. An optimization algorithm is used with a mix of discrete and continuous variables of component geometries, materials and manufacturing. Use of FEM optimization gives a structure with minimum mass due to optimized plate thicknesses satisfying the constraints. The analytic method gives almost the same main optimum design results. It can be concluded that it is advantageous to use simultaneously analytical and FEM optimization methods since this causes interaction and produces synergy and opportunity for checking the results at global and local levels of the design.