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The tensile behaviour of a C/SiC minicomposite fabricated by chemical vapour infiltration was examined and the associated damage evolution was monitored by using acoustic emission (AE) technique. The microstruc-ture of minicomposite can be characterized by a uniformly thick SiC sheath, the thin fibre coatings, and large pores due to the tendency of...
Citations
... The application scope of grey system theory has extended to industry, economy, financial and other fields [7][8][9]. Although much scientific literature describes the mechanical behaviour of CMCs [10,11], there are few efforts dealing with the damage evolution of CMCs based on the grey system model. Therefore, the aim of this paper is to investigate the damage evolution of a C/SiC composite under tensile loading. ...
... The matrix B and Y imply the accumulated matrix and constant vector, respectively. Based on the parameters, the response function can be obtained by solving the corresponding differential equation, the so-called whitenization (or image) equation (11) The solution to the whitenization equation is shown below: ...
The damage evolution of a C/SiC composite was investigated by repeated loading/unloading tests in terms of the reloading modulus and residual strain. Grey models were established for both the evolution of the damage factor and residual strain. The larger developmental coefficient of the evolution of the modulus suggests its competency to characterize the damage evolution relative to the residual strain. Excellent agreement between predictions and experimental results was obtained for both the grey models.
The carbon fiber tows covered by Si3N4 nanowires were densified using chemical vapor infiltration (CVI) technique to form mini-C/SiC composites reinforced by Si3N4 nanowires (Mini-C/SiC–Si3N4-NW). The tensile behaviors of the composites were examined, and the associated damage evolutions were monitored by the acoustic emission (AE) method. Compared with the traditional mini-C/SiC composites (Mini-C/SiC), the matrix strength and fracture strength of Mini-C/SiC–Si3N4-NW were increased by about 100% and 8%, respectively, due to the introducing of Si3N4 nanowires reinforcements. The density of Si3N4 nanowires and volume fraction of carbon fibers played important roles in the matrix strength and fracture strength of the mini-composites, respectively. Moreover, owning to the extra deposition surfaces provided by the Si3N4 nanowires, the CVI cycles of Mini-C/SiC–Si3N4-NW were 50% shorter than that of the Mini-C/SiC.
