An equivalent method for cross-scale thermal analysis of fiber-toughened composites with multiple criteria

Abstract

The fiber reinforcement composite material of the invention of the invention cross -scale thermal analysis equivalent method, the steps are as follows: establish a random representative unit, use the Monte‑carlo method within the unit to enhance the CMC fiber to enhance the distribution;Reprencentative Volume Element, probability statistical representative unit) and the finite element simulation of it, obtains the heat conduction coefficient, material temperature gradient field, and thermal density field of composite materials; adjust the PRVE size again to meet the heat physical quantity.After the average value, variance, and cross -entropy and other multiple convergence judgments, determine the critical PRVE size, obtain the distribution of composite thermal conductivity, temperature gradient field, and thermal density field, and establish a corresponding relationship between micro -structure and macro characteristics.The present invention fully considers the non -mean characteristics of the internal composite materials and the existence of physical decentralization. It provides a judgment basis for how to determine how to determine the critical PRVE size in the thermal analysis of the composite material, which can more accurately establish the corresponding relationship between micro -structure and macro characteristics.

Description

Technical field: [0001] The invention relates to an equivalent method for cross-scale thermal analysis of fiber toughened composite materials with multiple criteria, which belongs to the technical field of engineering thermophysics. Background technique: [0002] With the development of industrial technology, various composite materials have been widely used in various industrial fields, especially in the field of aerospace. Taking ceramic matrix composites as an example, as a non-metallic material, compared with commonly used metal materials and polymer materials, it has excellent properties such as high temperature resistance, wear resistance, and corrosion resistance, so it has attracted more and more attention. . However, limited by its brittleness, ceramic materials lack sufficient strength and reliability when used on stressed structural components such as engine turbines, so they cannot be directly applied. At present, it has become one of the most effective ways to...

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Problems solved by technology

However, the actual complex structure inside the actual CMC material makes it extremely difficult to obtain a single type of RVE, and whether the RVE criterion established in some existing mechanical property research fields can be directly applied to the field of thermal analysis, or how to improve it, no scholars have carried out related proof work

At the same time, the fixed value of thermal conductivity obtained by using a single RVE cannot fully reflect the characteristics of the dispersion of physical properties of CMC materials.

The existence of these problems makes the RVE method still have certain deficiencies in the thermal analysis of composite materials.

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