V. Kalyanaraman

Bio: V. Kalyanaraman is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Topology optimization & Box girder. The author has an hindex of 2, co-authored 3 publications receiving 15 citations.

Optimum design of fibre composite stiffened panels using genetic algorithms

Abstract: A procedure is derived for a generalized optimum design of stiffened panels made up of laminated fibre reinforced plastics (FRP) and subjected to longitudinal membrane compression (in the direction of stiffeners) and in plane shear loading. The strength and stability (local and overall) are the main design constraints. The size, configuration, fibre orientation and topology optimization are done simultaneously. The optimum design procedure is based on genetic algorithms and a simplified set of design equations. A few example problems of optimum design are solved and the results are discussed.

Optimum design of lattice portal frames

Abstract: Lattice portal frame structures fabricated using hot rolled angle sections for corner leg members laced together are often very economical systems for industrial structures. There is considerable flexibility in the design of such structures in terms of the spacings between and the unsupported lengths of corner leg members, besides the areas of the different elements of the frame. The minimum weight design of these frames is a nonlinear optimization problem which has been solved by using Rosen's gradient projection method. A computer program OPTFRAM, developed for the minimum weight design of lattice portal frames used in industrial structures, is described. This paper also presents the results of a parametric study carried out using the (OPTFRAM) computer program. Regression equations obtained from this study arc presented for use in day to day design.

A comparative study of genetic algorithms for the multi-objective optimization of composite stringers under compression loads

Abstract: Optimization methods are close to become a common task in the design process of many mechanical engineering fields, specially those related with the use of composite materials which offer the flexibility in the design of both the shape and the material properties and so, are very suitable to any optimization process. While nowadays there exist a large number of solution methods for optimization problems there is not much information about which method may be most reliable for a specific problem. Genetic algorithms have been presented as a family of methods which can handle most of engineering problems. However, starting from a common basic set of rules many algorithms which differ slightly from each other have been implemented even in commercial software packages. This work presents a comparative study of three common Genetic Algorithms: Archive-based Micro Genetic Algorithm (AMGA), Neighborhood Cultivation Genetic Algorithm (NCGA) and Non-dominate Sorting Genetic Algorithm II (NSGA-II) considering three different strategies for the initial population. Their performance in terms of solution, computational time and number of generations was compared. The benchmark problem was the optimization of a T-shaped stringer commonly used in CFRP stiffened panels. The objectives of the optimization were to minimize the mass and to maximize the critical buckling load. The comparative study reveals that NSGA-II and AMGA seem the most suitable algorithms for this kind of problem.

Optimum Design of Composite Structures: A Literature Survey (1969-2009)

Abstract: Optimum structural design of composites is a research subject that has drawn the attention of many researchers for more than 40 years with a growing interest. In this study, a review of the literature on this subject is presented. The papers are classified according to the type of the composite structure optimized in those studies, the loading conditions, the objective function, the structural analysis method, the design variables, the constraints, the failure criteria, and the search algorithm used by the researchers.

Optimisation of stiffeners for maximum fundamental frequency of cross-ply laminated cylindrical panels using social group optimisation and smeared stiffener method

Abstract: A review of the literature reveals a dearth of research on the maximisation of natural frequencies of laminated composite stiffened panels. The present study combines an analytical solution based on the smeared stiffener method with a novel social group optimisation (SGO) algorithm to develop a procedure for the solution of such an optimisation problem. For this purpose, cross-ply laminated circular-cylindrical panels with a simply supported condition, stiffened by stringers and rings, are considered. The quantities and sizes of the stiffener are optimised to maximise the fundamental frequency of the panels under practical constraints. Example optimisations of various panel geometries are performed. The optimisation results show that the fundamental frequency can be increased significantly by using tailored rings and that for the considered numerical examples, stringers do not make any beneficial contribution to the maximisation of the fundamental frequency. It is also demonstrated that the SGO algorithm is an efficient tool for this kind of mixed-integer constrained optimisation problem.