Prediction method of fracture and failure behavior of micro-nano fiber reinforced composites

Abstract

The invention discloses a fracture failure behavior prediction method of micro-nano fiber reinforced composite material. The method comprises the following steps of describing mechanical behaviors ofthe composite material through a multi-scale method, and establishing a slippage-enrichment bandwidth model of any fiber embedding length and a non-local slippage model of fibers in any direction; calculating fiber stress distribution and global load displacement response of the crack bridging area; by applying load and boundary conditions and iteratively updating cracks, acquiring a stress-strain relationship and a load displacement curve, making stress-strain information transmission from a fiber reinforced composite material mesoscopic model to macroscopic multi-field coupling and acquiring an analysis result of composite material mesoscopic local characteristics on macroscopic global load displacement response. According to the invention, the fracture failure process of the compositematerial can be accurately simulated while the bridging effect of the fibers is realized.

Description

technical field [0001] The invention relates to a technology in the field of fracture damage of aviation composite materials, in particular to a method for predicting the fracture damage behavior of micro-nano fiber-reinforced composite materials based on bridging reinforcement simulation. Background technique [0002] The mechanical properties of existing micro-nano fiber reinforced composites are generally evaluated by establishing crack bridging constitutive structures through fiber bridging stress and crack openings, but these methods cannot study the fracture behavior of composite materials from a global perspective, such as load-displacement curves, matrix stresses, etc. distribution etc. [0003] The extended finite element method (XFEM) model realizes the bridging between the fiber and the matrix by combining the cohesive force constitutive relationship of the matrix and the stress-opening displacement relationship of the fiber, thereby simulating the macroscopic fai...

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Problems solved by technology

However, the extended finite element method ignores the influence of interfacial shear stress on fiber pullout, and cannot obtain accurate matrix stress distribution, resulting in inaccurate crack growth results

[0004] The micromorphical model can overcome the above shortcomings by introducing an additional slip field between the matrix and the reinforcement, and realizes the fracture and failure analysis of composite materials with randomly distributed reinforcements. However, in order to accurately describe the randomly distributed reinforcement body, more slip fields need to be introduced, which not only increases the complexity of the calculation, but also reduces the calculation efficiency

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