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Numerical investigations of CMC nozzle structures: constitutive modelling and finite element technology
Author(s) -
Barfusz Oliver,
Schwarze Marco,
Reese Stefanie
Publication year - 2017
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201710168
Subject(s) - materials science , constitutive equation , nozzle , finite element method , curvature , anisotropy , ceramic , mechanics , composite material , mechanical engineering , structural engineering , engineering , physics , geometry , mathematics , quantum mechanics
This work deals with the development of numerical tools predicting the lifetime of nozzle structures made of ceramic matrix composites (CMC). These materials are favorable for thermostructural components due to their excellent specific mechanical properties, high thermal conductivity and thermoshock resistance. The anisotropic constitutive behaviour of the CMC is reflected by a continuum model which is micro‐mechanically motivated. The model is based on structural tensors representing different fibre orientations. Furthermore, the thin structure of the nozzle requires an appropriate finite element technology in order to overcome locking phenomena. For this reason, a solid‐shell formulation with reduced integration is utilized, for which the implementation of the fibre orientation is crucial. The enhanced assumed strain (EAS) concept is used to avoid volumetric locking as well as Poisson thickness locking. The transverse shear and curvature thickness locking are cured by the assumed natural strain (ANS) concept. Using reduced integration together with hourglass stabilization leads to high computational efficiency. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)