# Multiscale Prediction for Mechanical and Thermal Properties of Needled Composites Considering Pore and Their Application

## TL;DR

This paper uses multiscale modeling to predict mechanical and thermal properties of needled ceramic composites, considering the impact of pores.

## Contribution

The study introduces a novel multiscale method to correlate porosity with elastic modulus and thermal diffusion coefficient in ceramic composites.

## Key findings

- X-ray CT identified pores, and multiscale models were used to predict elastic modulus and thermal diffusion coefficient.
- The relationship between porosity and both elastic modulus and thermal diffusion coefficient was established.
- Correlation equations were developed to link porosity, elastic modulus, and thermal diffusion coefficient.

## Abstract

Needled ceramic composites have great application prospects for high-temperature structural components. However, due to the manufacturing defects, the properties of the composite show significant dispersion, which poses great challenges for predicting the service life. Firstly, X-ray computed tomography was used to determine the pores in the composites, and multiscale models considering the pores were established. Combined with the multiscale method, the elastic modulus was predicted, and the relationship between porosity and elastic modulus was established. Secondly, the thermal diffusion coefficient was predicted. The relationship between porosity and thermal diffusion coefficient was determined. The accuracy of the multiscale method was verified by comparative analysis with the tensile experiment and the thermal diffusion experiment, respectively. Finally, based on the results of the model analysis, the correlation equations between thermal diffusion coefficient, porosity and elastic modulus were established. Thereby, new ideas are provided for the assessment of porosity and elastic properties of the composites.