Design of rectangular composite plates with circular holes

Marek Barski, Piotr Kędziora, Małgorzata Chwał

Quarterly No. 1, 2016 pages 52-57

DOI:

keywords: plate with hole, optimization, stacking sequence, discrete design variables, Finite Element Method

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abstract The presented work is devoted to the problem of the optimal design of a multilayered composite structure. A square composite plate of geometrical dimensions 250x250x3 mm with a circular hole of diameter d = 100 mm is investigated. The structure is made of composite material, which consists of N = 12, 16 or 20 layers. Each layer is made of the same material, namely carbon fibers with epoxy resin (CFRP, fibers T300, matrix N5208). It is also assumed that the feasible fiber orientation angles are 0º, ±45º, 90º. The layer stacking sequence is symmetric with respect to the middle surface of the studied plate. The structure is subjected to uniform tension in the horizontal and vertical directions. Calculations are performed for the following load ratios, namely: p_hp_v = 0, 0.5, 0.75, 1.0, where p_h and p_v denote the load in the horizontal and vertical directions, respectively. The optimization problem is stated as follows: we look for the stacking sequence (the number of layers with fiber orientation angle equal to 0º, ±45º, 90º, respectively), which ensures the maximal value of the load multiplier. In order to find the solution to the optimization problem, the advanced concept of the discrete design variable is introduced. The use of these variables significantly simplifies the optimization process. In consequence, a very simple optimization procedure can be utilized. All the necessary computations are carried out with the use of the commercial finite element package ANSYS 12.1. The analyzed plate is modeled as a shell structure. The optimal solution mainly depends on p_hp_v. The total number of layers also has a slight influence on the obtained solution. The results are presented in graphs and collected in tables.