Tailoring of composite cantilever beam for maximum stiffness and minimum weight

Abstract

As the natural resources goes on decreasing now a days and to meet the needs of natural resources conservation, energy economy most of the manufacturers and their sub contractors are attempting to reduce the weight of the members in recent years. In this approach they are searching for low cost, high strength to weight ratio materials. Substituting composite structures for conventional metallic structures has many advantages because of higher specific stiffness and strength of composite materials. Composite materials have the major advantage of high strength to weight ratio with continuously decreasing travel of cost in addition to other advantages like excellent corrosive resistance, superior torsional buckling and fatigue strength and high specific strain energy storage capacity. The present work aims at the suitability of composite materials usage, by the identification of optimal fiber orientation stacking sequence and tailoring for laminate thickness/width for maximum stiffness and minimum weight design of laminated composite beam. The structural response is evaluated from conventional metallic structure with optimization techniques for maximizing stiffness and minimum weight. These metallic optimum values are extended initially to composite beam to maintain strength with the developed of optimization algorithm. Later with topology optimization and by tailoring cross-sections algorithm of the beam is evaluated with optimal fiber orientations and stacking sequence to maintain strength as in additional advantage of less weight for composites. Tailoring is done based on gradual decrement in cross-section over the length in both thickness and width direction. Numerical results are presented for cantilever beam with different geometries showing the maximizing stiffness and with minimum weight. The results indicate that the devised strategy is well suited for finding optimal fiber orientations and laminate thickness/width in the tailoring design of slender laminated composite structure.