Estudo Geralhttps://estudogeral.sib.uc.ptThe DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Wed, 22 Jan 2020 23:59:39 GMT2020-01-22T23:59:39Z5031A Class of Mathematical Programs with Equilibrium Constraints: A Smooth Algorithm and Applications to Contact Problemshttp://hdl.handle.net/10316/7739Title: A Class of Mathematical Programs with Equilibrium Constraints: A Smooth Algorithm and Applications to Contact Problems
Authors: Figueiredo, Isabel N.; Júdice, Joaquim J.; Rosa, Silvério S.
Abstract: We discuss a special mathematical programming problem with equilibrium constraints (MPEC), that arises in material and shape optimization problems involving the contact of a rod or a plate with a rigid obstacle. This MPEC can be reduced to a nonlinear programming problem with independent variables and some dependent variables implicity defined by the solution of a mixed linear complementarity problem (MLCP). A projected-gradient algorithm including a complementarity method is proposed to solve this optimization problem. Several numerical examples are reported to illustrate the efficiency of this methodology in practice.
Sat, 01 Jan 2005 00:00:00 GMThttp://hdl.handle.net/10316/77392005-01-01T00:00:00ZComplementarity and genetic algorithms for an optimization shell problemhttp://hdl.handle.net/10316/11475Title: Complementarity and genetic algorithms for an optimization shell problem
Authors: Figueiredo, Isabel N.; Júdice, Joaquim J.; Oliveira, Pedro N.
Abstract: The application of complementarity and genetic algorithms to an optimization
thin laminated shallow shell problem is discussed. The discrete form of the problem
leads to a Mathematical Program with Equilibrium Constraints (MPEC) [1], whose constraint
set consists of a variational inequality and a set of equality constraints. Furthermore
the variables are discrete. Special instances of the general problem are considered and indicate
that the choice of the algorithm depends on the problem to be linear or nonlinear.
Sat, 01 Jan 2000 00:00:00 GMThttp://hdl.handle.net/10316/114752000-01-01T00:00:00ZOn the solution of a finite element approximation of a linear obstacle plate problemhttp://hdl.handle.net/10316/11459Title: On the solution of a finite element approximation of a linear obstacle plate problem
Authors: Fernandes, Luís M.; Figueiredo, Isabel N.; Júdice, Joaquim J.
Abstract: In this paper the solution of a finite element approximation of a linear obstacle plate problem is investigated. A simple version
of an interior point method and a block pivoting algorithm have been proposed for the solution of this problem. Special
purpose implementations of these procedures are included and have been used in the solution of a set of test problems.
The results of these experiences indicate that these procedures are quite efficient to deal with these instances and compare
favourably with the path-following PATH and the active-set MINOS codes of the commercial GAMS collection.
Mon, 01 Jan 2001 00:00:00 GMThttp://hdl.handle.net/10316/114592001-01-01T00:00:00Z