An elastic–plastic constitutive model for ceramic composite laminates

Abstract

a b s t r a c tExisting phenomenological constitutive models are unable to capture the full range of behaviors of ceramic composite laminates. To ameliorate this deficiency, we propose a new model based on the deformation theory of plasticity. The predictive capabilities of the model are assessed through comparisons of computed and measured strain and displacement fields in open-hole tension tests. The agreements in the magnitude of strains and in the size and shape of shear bands that develop around a hole are very good over most of the loading history. Some discrepancies are obtained at high stresses. These are tentatively attributed to non-proportional stressing of some material elements: a feature not captured by the present model.

Strain fields around strain‐concentrating features in fiber‐reinforced oxide composites

“…Inelasticity arises through the combinations of matrix microcracking, interfacial debonding and sliding, and fiber fracture. It facilitates redistribution of stresses around strain‐concentrating features, leading to more robust structural response . Predictive modeling of inelasticity in CMCs is expected to enable the designs of engineering components that are less conservative than those that emerge from purely elastic analyses.…”

“…Approaches to modeling inelastic deformation of CMCs fall into one of the three broad categories: micromechanics, continuum damage mechanics (CDM), and phenomenological plasticity . Micromechanical models relate constituent properties and microstructural characteristics with the physical mechanisms underlying inelasticity.…”

“…An exhaustive suite of micromechanical models has been developed to describe matrix cracking and interfacial debonding and sliding in unidirectional composites under simple stress states (eg, uniaxial tension, pure shear) and tunnel cracks in off‐axis plies of cross‐ply laminates . But these models are difficult to generalize to arbitrary multiaxial stress states and to account for typical fiber architectures and microstructural heterogeneities that naturally arise in most CMCs . Approaches based on CDM provide greater flexibility and are ostensibly able to capture a multitude of phenomena without explicit information about the mechanisms involved.…”

A finite fracture model for the analysis of multi-cracking in woven ceramic matrix composites

“…Phenomenological constitutive laws have been developed to reproduce the macroscopic stress-strain response of woven CMCs. One can find plasticity-like models [22] or damage mechanics based models [23][24][25]. These approaches are dedicated to structural analysis but often require the identification of a large number of parameters which are difficult to link to the actual damage mechanisms.…”

Effects of stochastic tow waviness on stiffness and strength of plain-weave ceramic matrix composites

“…Almost all works using the Binary Model assumed that effective medium elements are taken to be isotropic and tow elements are considered to be linear elastic. Such as those of Flores et al, 16 Rajan et al 17 and Rossol et al; 18 they used a linear Drucker-Prager yield criterion for failure initiation in the effective medium along with isotropic elastic-plastic evolution law. Yang and Cox 19 employed the rule of mixture to determine the material properties and assumed that the effective medium is isotropic and the properties of both virtual constituents are linear elastic.…”