Apresentam-se dois modelos matemáticos de otimização os quais, considerando os dados do trânsito da região que se pretende otimizar, possibilitam fornecer tempos de verde que visam minimizar o tempo de percurso veicular. Também são apresentados os resultados computacionais obtidos com a investigação desses modelos em um estudo realizado na região central da cidade de Passo Fundo, RS.Os resultados apontam para uma melhora significativa no fluxo veicular, dando respaldo a um possível emprego destes modelos em situação real.

This work presents two mathematical optimization models, developed in order to minimize the course time delay in cities of medium and large size and taking the time of green in each traffic signal as the design variables. Some computational results are also presented, based on data collected for the transit of a central region of the city of Passo Fundo, RS. The results obtained point to the application of these formulations to real situations.

Esse trabalho apresenta um estudo numérico que objetiva a determinação do peso mínimo de perfis conformados a frio de seção U, com e sem enrijecedores de borda. Os modos de falha considerados incluem escoamento da seção, flambagem global por flexo - compressão, flexo-torção e flambagem local de placa. A obtenção das dimensões ótimas da seção é baseada nos preceitos da norma norte-americana AISI (2001) para comprimento e carga definidos a priori. A otimização foi efetuada através do Método do Recozimento Simulado (Simulated Annealing). Simulações numéricas são apresentadas com o intuito de validar o procedimento empregado, assim como um exemplo experimental que qualifica a implementação proposta.

This paper presents a numeric study that aims to obtaining minimum weight of cold-formed channel columns, with and without lips. Flexural, torsional and torsional-flexural buckling of columns were considered as constraints. The design of cold-formed steel columns was prepared on the basis of the 2001 edition of the North American Specification for the Design of Cold-Formed Steel Structural Members. The optimization was made through the Simulated Annealing method. Several numeric simulations are presented and discussed with the main goal of validate the proposal, as well as an experimental example that qualifies the implementation.

At present, several methods are available for optimization of structures. The application of such methods to real structural problems, however, has not been as intense as the development of the techniques themselves. One of the main reasons is that the great majority of the methods, based on mathematical programming, consider a continuous search space. This paper presents an application of the Simulated Annealing method to the optimization of trusses considering the cross sections of the members as discrete variables. The constraints imposed to the analysis were the allowable stresses and the displacements on nodes. Some examples are presented in order to demonstrate the effectiveness of the method when compared with other methods found in literature.