Multiscale prediction method for mechanical property of woven composite material

Abstract

The invention relates to a multiscale prediction method for the mechanical property of a woven composite material. The method comprises the following steps that 1), an initial parameter is input; 2), elastic stiffness matrixes of a fiber / basal body scale, a fiber bundle scale and a unit cell scale are computed sequentially according to a bottom-to-top homogenization process; 3), a multiscale incidence matrix is constructed; 4), stress-strain analysis is performed on unit cell entirety, stress is decomposed by the multiscale incidence matrix from top to bottom, and stress-strain fields under all the scales are obtained synchronously; 5), whether an ingredient material is in a failure is judged according to respective failure criteria of a fiber and a basal body; if so, the corresponding ingredient material is subjected to stiffness reduction; 6), whether the unit cell entirety is in a failure is judged, and if so, Step 7) is executed, or else, a next displacement increment is added and Step 2) is returned; and 7), stiffness and strength computation results of the woven composite material are output. Compared with the prior art, the method has the advantages of high computation efficiency, high precision, high universality and the like.

Description

Technical field [0001] The invention relates to a method for predicting the mechanical properties of a braided composite material, in particular to a multi-scale prediction method for the mechanical properties of a composite material. Background technique [0002] Braided composite materials have great potential in improving the strength, damage tolerance and thermal stress distribution in the interlayer, and have been widely used in various industrial fields in recent years. The microstructure of woven composites is very complex, and there are many factors affecting its mechanical properties, such as the properties of component materials, fiber volume content, fiber bending angle, fiber interweaving method, manufacturing error, etc., making the prediction of its mechanical properties a Complex and challenging work. At present, two types of methods are generally used at home and abroad to calculate the mechanical properties of braided composites, namely analytical methods and nu...

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Problems solved by technology

Although this method can simulate the internal structure of braided composite materials, it takes a lot of time and computer resources for modeling and analysis, and it is difficult to guarantee the accuracy and efficiency of calculations.

The existing analytical methods can determine the macroscopic mechanical properties of braided composites according to the mechanical properties and geometric parameters of the constituent materials, but there are also some defects: (1) The correlation between scales is ignored, resulting in low calculation accuracy; ( 2) Only the macroscopic mechanical properties can be obtained, and the stress-strain field at the fiber bundle scale and the fiber / matrix scale cannot be obtained at the same time; (3) It is difficult to consider the influence of manufacturing errors on its mechanical properties; (4) Complex geometric functions are used to describe fibers (5) The versatility is not strong, and it is difficult to calculate complex braided configurations, such as three-axis braided composites or three-dimensional braided composites

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