MODIFIED TRAJECTORY METHOD FOR PRACTICAL GLOBAL OPTIMIZATION PROBLEMS

A modification of the Snyman-Fatti (SF) stochastic multistart trajecto ry method for global optimization is developed, in tile modified SF al gorithm, distinction is made between a global and a local phase in the application of the original minimization procedure for a particular s tarting point, The global phase ensures convergence to the neighborhoo d of a relative low local minimum, whereas in the local phase further accuracy is pursued. Different choices of parameter values are propose d for the individual phases, and a procedure is proposed to deal with simple bound violations. The modifications lead to substantial improve ment in the efficiency of tile original trajectory method, The perform ance of the modified algorithm is assessed by its application to a sel ection of test problems and the results are compared with those of som e other methods, The method is also successfully applied to laminate s tructural problems in which optimal sequences of the ply orientations of the layers are determined.