Analytical modeling of the interfacial stress state during pushout testing of SCS-6/Ti-Based composites

• Published in: Acta metallurgica et materialia Vol. 42; no. 11; pp. 3895 - 3908
• Main Authors: Ghosn, L.J., Eldridge, J.I., Kantzos, P.
• Format: Journal Article
• Language: English
• Published: Tarrytown, NY Elsevier B.V 01.11.1994; Pergamon Press
• Subjects: 360603 - Materials- Properties; ALLOYS; Applied sciences; CARBIDES; CARBON COMPOUNDS; COMPOSITE MATERIALS; Exact sciences and technology; FAILURES; Fibre reinforced metals; INTERFACES; MATERIALS; MATERIALS SCIENCE; MATERIALS TESTING; MECHANICAL PROPERTIES; MECHANICAL TESTS; Metals. Metallurgy; Powder metallurgy. Composite materials; Production techniques; SHEAR PROPERTIES; SILICON CARBIDES; SILICON COMPOUNDS; STRESS ANALYSIS; STRESSES; TESTING; THERMAL STRESSES; TITANIUM ALLOYS; TITANIUM BASE ALLOYS; Thermal stress; Temperature dependence; Fibre reinforced metal; Niobium alloy; Aluminium alloy; Experimental study; Adhesion; Titanium base alloys; Composite material; Thickness; Silicon carbide; Stress distribution; Residual stress; Interface
• ISSN: 0956-7151; 1873-2879
• DOI: 10.1016/0956-7151(94)90455-3

Analytical and experimental investigations were performed to determine the stress components responsible for interfacial debonding during pushout testing. The stress distributions along the fiber/matrix interface were modeled using finite element methods. Both thermal residual stresses as well as mechanical stresses were accounted for in the analysis. The analysis was performed for two SCS-6/Ti-based composite systems. The analytical results were calculated based on experimentally determined fiber debonding loads obtained at different specimen thicknesses and testing temperatures. The results of the analysis were consistent with the experimentally observed initiation failure sites. At room temperature, due to large thermal residual shear stresses, the maximum shear stress during thin-specimen pushout was located at the bottom face away from the indenter and was found to control the initiation of interfacial debonding. However, in very thin specimens, the bending stresses control interfacial debonding by causing radial opening at the bottom face. With an increase in temperature the analytical modeling shows that the maximum shear stress moves to the top face, due to the relaxation of the residual shear stresses. However, at high temperature the bending stresses result in failure initiation on the bottom face due to the softening of the matrix and the relaxation of the radial clamping stresses.