Experimental investigation of the degradation of ceramic composites in aggressive thermomechanical environments

[摘要] To support a design methodology using monolithic and ceramic composites for use in aerospace components, an experimental test programme was initiated at Engineering Design and Research Center (EDRC) /Glasgow University (GU) in 1990 to test advanced materials at ambient and elevated temperatures. This was carried out in conjunction with computer modelling and design system development. The facilities based at GU were restricted to thermal macromechanical testing. Due to the difficulty of achieving reproducible and reliable data from, eg tensile testing, simpler flexure and compression tests were preferred. Thermal shock, identified as a potential cause of failure in engineering ceramics, was shown by computational analysis to be less important than initially assumed. This was however not confirmed experimentally. Ambient and elevated macromechanical testing was therefore restricted to flexure tests carried out in an air environment under steady state conditions. The main focus of the test programme was to understand the physics of the composite materials and in particular the failure modes associated with specific loading configurations. Investigations of damage at stress concentrations or changes in fibre architecture and of delamination effects through varying changes in thickness was a key part of the study. The flexure tests would not only establish a materials properties and performance database, but will allow the fibre architecture of the loaded structure to be fully optimised.

[发布机构] University:University of Glasgow

[关键词] Materials science