Lifetime Testing of a CMC TPS under Vibration Load

Abstract

A ceramic matrix composite thermal protection system test article was subjected to a dynamic load environment to determine its lifetime. The test article consisted of one panel made from the ceramic matrix composite and the corresponding structural items to mount on a substructure. Special attention was given to the fasteners which were also designed and made from the ceramic matrix composite. An elastic foam material was included between panel and carrier structure which is representative of a flexible high-temperature insulation. The setup is representative of the design that was developed for re-entry vehicles like the SHEFEX I and II flight experiments. A mechanical random vibration load was defined typical of the acoustic loads present around a hypersonic flight vehicle in a turbulent boundary layer. The tests were carried out on a shaker in one direction perpendicular to the panel surface. A total test time of 100 hours was accumulated without noticeable degradation of the fastener performance or the other test items. NomenclatureC/C = Carbon/Carbon C/C-SiC = Carbon/carbon-silicon carbide CFRP = Carbon fiber reinforced plastic CMC = Ceramic matrix composite DLR = Deutsches Zentrum für Luft-und Raumfahrt RTM = Resin transfer molding SHEFEX = Sharp Edge Flight Experiment TPS = Thermal protection system