Micromechanical Evolutionary Elastoplastic Damage Model for Fiber-Reinforced Metal Matrix Composites With Fiber Debonding

Author(s):  
J. W. Ju ◽  
H. N. Ruan ◽  
Y. F. Ko

A micromechanical evolutionary damage model is proposed to predict the overall elastoplastic behavior and interfacial damage evolution of fiber-reinforced metal matrix composites. Progressive debonded fibers are replaced by equivalent voids. The effective elastic moduli of three-phase composites, composed of a ductile matrix, randomly located yet unidirectionally aligned circular fibers, and voids, are derived by using a rigorous micromechanical formulation. In order to characterize the overall elastoplastic behavior, an effective yield criterion is derived based on the ensemble-area averaging process and the first-order effects of eigenstrains.

2005 ◽  
Vol 475-479 ◽  
pp. 3299-3302
Author(s):  
M. Zhang ◽  
W.L. Zhang ◽  
M.Y. Gu

To improve the transverse properties of fiber-reinforced metal matrix composites, a three-phase material model was proposed. In the model the reinforcing fibers are surrounded by a weak metal matrix, which in turn is encircled by another strong metal matrix. The weak matrix acts as a role to protect the fibers from damage and the strong matrix acts as a role to improve the transverse properties of the composite. Based on the material model, FEM model was established and parameter analysis was carried out to determine the influence of matrix strengths and fibers spatial distribution on the transverse mechanical behavior of the three-phase composite. It was found that the yield strength of the three-phase composite was mainly dictated by the matrix directly surrounding fibers and the effect from another matrix on the yield strength can be neglected. The three-phase composite has a higher transverse strength with hexagonal fiber arrangement than with regular square fiber arrangement.


2021 ◽  
Vol 30 ◽  
pp. 2633366X2092971
Author(s):  
Ying Ba ◽  
Shu Sun

Fiber-reinforced metal matrix composites have mechanical properties highly dependent on directions, possessing high strength and fatigue resistance in fiber longitudinal direction achieved by weak interface bonding. However, the disadvantage of weak interface combination is the reduction of transversal performances. In this article, tensile and fatigue properties of carbon fiber-reinforced 5056 aluminum alloy matrix (Cf/5056Al) composite under the condition of medium-strength interface combination are carried out. The fatigue damage mechanisms of Cf/5056Al composite under tension–tension and tension–compression loads are not the same, but the fatigue life curves are close, which may be the result of the medium-strength interface combination.


1999 ◽  
Vol 122 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Chuwei Zhou ◽  
Wei Yang ◽  
Daining Fang

Mechanical properties and damage evolution of short-fiber-reinforced metal matrix composites (MMC) are studied under a micromechanics model accounting for the history of cooling and thermal cycling. A cohesive interface is formulated in conjunction with the Gurson-Tvergaard matrix damage model. Attention is focused on the residual stresses and damages by the thermal mismatch. Substantial stress drop in the uniaxial tensile response is found for a computational cell that experienced a cooling process. The stress drop is caused by debonding along the fiber ends. Subsequent thermal cycling lowers the debonding stress and the debonding strain. Micromechanics analysis reveals three failure modes. When the thermal histories are ignored, the cell fails by matrix damage outside the fiber ends. With the incorporation of cooling, the cell fails by fiber end debonding and the subsequent transverse matrix damage. When thermal cycling is also included, the cell fails by jagged debonding around the fiber tops followed by necking instability of matrix ligaments. [S0094-4289(00)01202-0]


1995 ◽  
Vol 62 (2) ◽  
pp. 441-449 ◽  
Author(s):  
K. B. Milligan ◽  
V. K. Kinra

Recently, taking the second law of thermodynamics as a starting point, a theoretical framework for an exact calculation of the elastothermodynamic damping in metal-matrix composites has been presented by the authors (Kinra and Milligan, 1994; Milligan and Kinra, 1993). Using this work as a foundation, we solve two canonical boundary value problems concerning elastothermodynamic damping in continuous-fiber-reinforced metal-matrix composites: (1) a fiber in an infinite matrix, and (2) using the general methodology given by Bishop and Kinra (1993), a fiber in a finite matrix. In both cases the solutions were obtained for the following loading conditions: (1) uniform radial stress and (2) uniform axial strain.


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