Method for predicting interface failure and mesoscopic crack propagation of composite material under hydraulic osmotic load

Abstract

The invention discloses a method for predicting interface failure and microscopic crack propagation of a composite material under a hydraulic osmotic load. The method comprises the following steps: representing a fracture state and interface distribution of a model by using a fracture phase field and an interface phase field; combining a phase field method and a Biot pore elastic medium theory inthe simulation and prediction process, calculating distribution of a displacement field and a liquid pressure field of the model under a hydraulic load, calculating the influence of the displacement field on the fracture phase field, and therefore achieving simulation of crack growth of a composite material under the mesoscopic scale when the composite material is subjected to the hydraulic load.According to the method, the interface normal rigidity and tangential rigidity are considered in a cohesion interface model. According to the phase field method model, the growth and bifurcation of the microscopic cracks of the composite material can be accurately simulated.

Description

technical field [0001] The invention relates to the technical field of composite materials, in particular to a method for predicting interface failure and mesoscopic crack propagation of composite materials under hydraulic seepage loads. Background technique [0002] The cryogenic tank is an integral structure in the rocket. The material selection of the storage tank is closely related to its bearing mode and the development level of the manufacturing process. With the development of composite material technology, the combination of metal and non-metallic materials (composite materials) is also used in the manufacturing process of tanks. The new generation of tank materials is usually chosen as composite materials without metal inner lining. With the continuous research and development of composite materials with excellent thermal cycle mechanical properties, the all-composite material tank without metal inner lining has become the main development direction of spacecraft l...

AI Technical Summary

Problems solved by technology

Existing fracture and failure problems of composite pressure vessels are mainly solved by traditional laminate theory and stress factor method, but this method cannot predict the occurrence and development of cracks at the mesoscopic scale.

The reason is that this method is a geometric description method, and the crack is based on grid expansion, such as element deletion method (unit failure method), interface element method, etc. The simplest is the element deletion method, which only needs to set the stress of the element when the condition is met. zero, but the element deletion method is insufficient in calculating crack bifurcations

The interface element method is the simplest method to calculate the crack score. By inserting cohesive force elements at the element boundary, the crack can expand arbitrarily at the element boundary. When the element boundary reaches the fracture criterion, the interface element will fail, but for the grid is dependent and numerically unstable

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