Experimental and finite element analyses of advanced carbon-carbon (ACC-4) composites under tensile loading

Conference · Fri Dec 31 00:00:00 EST 1993

OSTI ID:143710

Mahfuz, H; Xue, D; Jeelani, S ^[1]; Baker, D; Johnson, S ^[2]

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1. Tuskegee Univ., AL (United States). Materials Research Lab.
2. General Dynamics, Fort Worth, TX (United States)

Laminated coupons of woven 2-D carbon/carbon (C/C) composites coated with SiC were modeled using isoparametric layered shell elements. Transverse shear deformation through the thickness was assumed constant, and two rotations about the in-plane axes were considered in the total degrees freedom of the element. Non-linear response of standard test specimen under tensile loading were studied with the consideration of large deflection and plastic strain behavior. Analyses were performed at room, 1000{degree}F and 2000{degree}F temperatures to study the thermal expansion mismatch between the coating and the substrate. Stress and strain variation along the thickness, the width and the length are examined to understand the composite failure mechanisms. Experimental investigations have also been carried out at the above three temperatures to characterize C/C for the National Aerospace Plane (NASP) applications. Correlation between the experimental and the finite element data has been studied. The strength of C/C has been observed to increase with temperature ana the phenomenon is attributed to the shift in the failure mechanism. The load displacement behavior at three temperatures has been studied, and an increase in stiffness is noticed. Post failure analyses through the Optical, and Scanning Electron Microscopy were conducted to investigate the damage mechanism in the composite. Increase in interfacial bond strength between the fiber and the matrix at elevated temperature has been revealed by SEM, and longitudinal cracks through the matrix were found responsible for the composite failure at room temperature. Interlaminar shear stress distribution through the thickness has been studied in the finite element analysis, and the variation with temperature is discussed. Contour of transverse strains in the coating as well as in the substrate are presented, and the variation of stress distribution between the layers is discussed.

• OSTI ID: 143710
• Report Number(s): CONF-930246-; ISBN 0-87339-251-5; TRN: IM9413%%220
• Resource Relation: Conference: Advanced composites `93: international conference on advanced composite materials (ICACM), Wollongong (Australia), 15-19 Feb 1993; Other Information: PBD: 1993; Related Information: Is Part Of Advanced composites 1993; Chandra, T. [ed.] [Univ. of Wollongong (Australia)]; Dhingra, A.K. [ed.] [DuPont, Wilmington, DE (United States)]; PB: 1464 p.
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COMPOSITE MATERIALS
TENSILE PROPERTIES
THERMAL EXPANSION
SILICON CARBIDES
STATIC LOADS
TEMPERATURE DEPENDENCE