Design optimization of magnetorheological fluid valves using response surface method

A new design optimization methodology for the optimal design of a single-coil annular magnetorheological valve constrained in a specific volume inside a magnetorheological damper has been presented in this article. The methodology combines the finite element model, with the design of experiments and response surface techniques in order to develop approximate response surface functions for the magnetic field intensity across the activation length of a magnetorheological valve orifice with respect to identified design variables. The accuracy of the developed response surface functions over the entire design space has been verified. The developed analytical response functions have then been used in Bingham plastic model, which is based on the steady behavior of a magnetorheological fluid in order to derive the field-dependent performance functions of the magnetorheological damper, which can be effectively used in the design optimization problems. The design optimization problem has been formulated for single- and multiobjective performance functions using sequential quadratic programming technique and the genetic algorithm to find the global optimum geometrical parameters of the magnetorheological valve. Finally, a proportional–integral–derivative controller has been designed to evaluate the closed-loop performance of the optimally designed magnetorheological valve confined in a magnetorheological damper used in a quarter-car suspension model.