Optimal design method for bending rigidity ply sequence of symmetrical composite laminate

Abstract

The invention provides an optimal design method for bending rigidity ply sequence of symmetrical composite laminate, which comprises the following steps: screening a sensitivity laying angle at a certain specific laying position through a linear and nonlinear sensitivity detection technology, and sequentially replacing an existing laying angle with the sensitivity laying angle from a middle surface position to an external position for optimization. The method can effectively solve the problem of combined explosion of the equal-thickness composite laminated plate laying sequence design space, and the purposes of greatly improving the bending rigidity and improving the design efficiency are achieved.

Description

technical field [0001] The invention relates to the technical field of composite material laminates, in particular to an optimization design method for the bending stiffness laying sequence of symmetrical composite material laminates. Background technique [0002] Carbon fiber-reinforced resin-based composite materials have been widely used in modern aircraft thin-walled structures. The unidirectional tape refers to a thin sheet made of unidirectional fiber and resin with a thickness of about 0.2mm. The unidirectional tape is laminated together according to different orientation angles. The board is called a composite laminate or a laminated structure, and the orientation angle is also called the laying angle. A certain layup and its orientation angle are collectively called the corner layup, or simply called the layup. Equal-thickness composite laminates are mostly used in the shell structure inside the body, such as: stiffened plates, stiffened ribs and other structural pa...

AI Technical Summary

Problems solved by technology

[0005] (1) The optimization result is extremely sensitive to the initial parameters. For the same problem, repeated calculations are required to determine the appropriate initial parameters, and improper initial parameters will cause the algorithm to converge to a local solution in advance

[0006] (2) The optimization strategy of the heuristic algorithm, such as crossover, mutation, screening and other operators, does not consider the discrete characteristics of the laminate layer, the stiffness superposition rule by layer, and the intrinsic sensitivity information of the stiffness, which makes the heuristic algorithm Large amount of calculation, slow iteration convergence

[0007] (3) The heuristic algorithm needs to start at multiple points, and the uncertainty of the initial point leads to the randomness of the optimization result, so it cannot guarantee that the algorithm can find the global optimum

[0008] (4) The heuristic algorithm is difficult to deal with the engineering constraints of composite laminates. For example, it is required that the same ply in the laminate cannot be stacked more than 4 layers in a row, and the difference between the laying angles of adjacent plies must be less than 45°, etc.

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