Design optimisation of steel portal frames using modified distributed genetic algorithms

Distributed genetic algorithms have been modified in this study to improve their quality, performance, and convergence to the optimum solution for structural steel frames. This was achieved by introducing some novelties of the main algorithm of distributed genetic algorithms and applying them in structural optimisation. Among these are the creation of new mutation schemes, adding a crossover scheme, definition of a penalty function, properties of twins, and definition of the reproduction scheme. Many optimisation problems have been designed to minimise the weight of a steel structure and are well documented in the literature. However, having a frame controlled by displacement will necessitate choosing a different approach for the objective function. In addition to weight minimisation, attempts have been made to investigate displacement maximisation and this also forms part of the novelty of this study. Various steel frames in terms of geometry and loading conditions are considered during the optimisation process and they are assumed to have rigid and/or semi-rigid connections. The design optimisations are conducted according to therequirements of both BS 5950 and EC3 codes of practice. A stiffness matrix is developed for a non-prismatic member that is involved in the analysis process.

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Nottingham Trent University

Year dc:date.issued

2010

Author dc:creator

• Issa, HK

Language dc:language

en