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<p>The salient feature of polymeric composite materials is their temperature and heating rate-dependent stress-strain state. On high-temperature irradiation, such processes are termed ‘ablation’. Ablation is taken to mean the burning out of a component mass portion, and degradation is the change in its properties influenced by heat at high temperatures. The multiphase media model is used to analyze the efficiency of predicting the elastic characteristics, including ablation and thermal degradation processes. The change in relative composite density at high temperatures is represented by thermogravimetric curves plotted at fixed heating rates. At room temperature, the composite is believed to consist of two phases: polymer matrix and reinforcing fibers. In the matrix, two new phases, pyrolytic and gas, are generated at high temperatures. The initial fiber phase is termed ‘amorphous’, and its crystalline phase is also formed at elevated temperatures. The adopted structure formation scheme is based on the hypothesis that all phases exist simultaneously at any time in each element of the composite volume.</p>

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Internal Heat Transfer and Strength of Composite Ablators at High Temperatures

  • 期刊论文

  • 发表日期：

    2025年3月1日

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  • M. K. Kucher,
  • D. S. Avramenko,
  • O. O. Chyzhyk

摘要

The salient feature of polymeric composite materials is their temperature and heating rate-dependent stress-strain state. On high-temperature irradiation, such processes are termed ‘ablation’. Ablation is taken to mean the burning out of a component mass portion, and degradation is the change in its properties influenced by heat at high temperatures. The multiphase media model is used to analyze the efficiency of predicting the elastic characteristics, including ablation and thermal degradation processes. The change in relative composite density at high temperatures is represented by thermogravimetric curves plotted at fixed heating rates. At room temperature, the composite is believed to consist of two phases: polymer matrix and reinforcing fibers. In the matrix, two new phases, pyrolytic and gas, are generated at high temperatures. The initial fiber phase is termed ‘amorphous’, and its crystalline phase is also formed at elevated temperatures. The adopted structure formation scheme is based on the hypothesis that all phases exist simultaneously at any time in each element of the composite volume.