Behavior of SiC-SiC Composite Laminates Under Multiaxial Load States:Experiments and Simulations.

ceramic matrix composites;multiscale modelling;composite mechanics;Aerospace Engineering;Engineering;Aerospace Engineering

Hansen, Lucas R.Sundararaghavan, Veera ;

University of Michigan

关键词: ceramic matrix composites;    multiscale modelling;    composite mechanics;    Aerospace Engineering;    Engineering;    Aerospace Engineering;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/113470/lrhansen_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Fiber-reinforced ceramic reinforced composites are a promising material class for use in high temperature structural applications, such as the hot sections of gas turbine engines.Monolithic ceramics possess certain desirable properties under these service conditions: namely creep resistance and retention of strength at elevated temperature.Use of CMCs in engineering applications, however, is limited by the low toughness of ceramic monoliths.By reinforcing the ceramic with coated fibers, the toughness of the CMC is dramatically increased.However, the behavior of such materials under multiaxial load states is not well understood.To this end, CMC laminates are tested under a state of biaxial flexure at room and elevated temperature in an atmospheric environment.From these tests, the strength and strain-to-failure of a the CMC ply is determined. Analysis of composite materials can take several forms characterized by the level of homogenization: fully homogenized, ply-level homogenization (such as classical lamination theory) and constituent-level modeling using multiscale approaches.In this work, a multiscale approach combining finite element analysis at the coupon/component level and the generalized method of cells at the constituent level is used.Appropriate constituent failure models and failure criteria are determined, and the method is validated by a multiscale simulation of the biaxial flexure tests.It is shown that multiscale analysis gives a more accurate results than ply-level approaches using homogenized ply models combined with the smeared-crack model.