T-S fuzzy system for isothermal CVI process of C/C Composites

Isothermal CVI is one of the most important conventional techniques for the manufacture of C/C composites, because C/C composites fabricated by isothermal CVI possess some excellent properties and the isothermal CVI process utilizes relatively simple equipment. The isothermal CVI process, however, is a lengthy technical procedure with a high cost. The model of relation between densification rate or uniformity and the CVI process parameters should be built to guide the optimization of CVI process, and this is an important way of decreasing the fabricating cost of C/C composites. Unfortunately, the CVI process is influenced by so many factors that it cannot be easily and precisely modeled by "first principles" methods. In this paper, an experimental T-S fuzzy system model for isothermal CVI process was proposed based on the theory of fuzzy inference system, and this model was used to mine and express the experience that cannot be expressed by formulas. From the T-S fuzzy system, the mechanisms of main infiltration conditions had been studied, and in theory, they were good instructions for the optimization, design and control of CVI process.