A global solution for robust parameter design of aeronautical electrical apparatus based on interactions analysis and polynomial fitting

Robust Parameter Design(RPD) has been widely applied for improving quality and reliability of products.One of the key drawbacks of applying RPD using Taguchi method is that the stable factors may not be independent of the adjustment factors, resulting in unsatisfactory design.Moreover, the Taguchi method cannot guarantee global optimality since the levels set in the experiment are usually discrete to ensure orthogonal design.In this paper, robust solutions of the stable factors are obtained via a nonlinear model based on polynomial fitting;while the adjustment factors are obtained via interactions analysis so that they are independent of the stable factors.In particular, the values of the adjustment factors are determined by output offset compensation so as to achieve robustness of the design scheme.An example on the design of an aeronautical electrical apparatus is presented to illustrate the procedure.The results show that the proposed method can take full advantage of the nonlinearity in the response and achieve the desired outcome.

Solute Redistribution with Shear Flow in Molten Pool of Ni-Cr Alloy

Columnar grain growth with shear flow in molten pool of Ni-Cr alloy was simulated with a coupled model of grain growth and solute transport.The results indicate that shear flow alters solute distribution at the vicinity of columnar grains.The solute concentration gradient on the upstream side is greater,while that on the downstream side is smaller,leading to asymmetrical growth of columnar grains.In the interior of a columnar grain,solute concentration increases from the bottom to the dendrite tip,but the rate of increase tends to be reduced.The simulated results are consistent with the experiments.