Transformation field analysis of damage evolution in composite materials

2001 ◽  
Vol 49 (11) ◽  
pp. 2517-2541 ◽  
Author(s):  
George J. Dvorak ◽  
Jian Zhang
1994 ◽  
Vol 14 (3) ◽  
pp. 201-228 ◽  
Author(s):  
G. J. Dvorak ◽  
A. M. Wafa ◽  
Y. A. Bahei-El-Din

1993 ◽  
Vol 115 (4) ◽  
pp. 327-338 ◽  
Author(s):  
George J. Dvorak

Some recent theoretical and experimental results on modeling of the inelastic behavior of composite materials are reviewed. The transformation field analysis method (G. J. Dvorak, Proc. R. Soc. London, Series A437, 1992, pp. 311–327) is a general procedure for evaluation of local fields and overall response in representative volumes of multiphase materials subjected to external thermomechanical loads and transformations in the phases. Applications are presented for systems with elastic-plastic and viscoelastic constituents. The Kroner-Budiansky-Wu and the Hill self-consistent models are corrected to conform with the generalized Levin formula. Recent experimental measurements of yield surfaces and plastic strains on thin-walled boron-aluminum composite tubes are interpreted with several micromechanical models. The comparisons show that unit cell models can provide reasonably accurate predictions of the observed plastic strains, while models relying on normality of the plastic strain increment vector to a single overall yield surface may not capture the essential features of the inelastic deformation process.


A new method is proposed for evaluation of local fields and overall properties of composite materials subjected to incremental thermomechanical loads and to transformation strains in the phases. The composite aggregate may consist of many perfectly bonded inelastic phases of arbitrary geometry and elastic material symmetry. In principle, any inviscid or time-dependent inelastic constitutive relation that complies with the additive decomposition of total strains can be admitted in the analysis. The governing system of equations is derived from the representation of local stress and strain fields by novel transformation influence functions and concentration factor tensors, as discussed in the preceding paper by G. J. Dvorak and Y. Benveniste. The concentration factors depend on local and overall thermoelastic moduli, and can be evaluated with a selected micromechanical model. Applications to elastic-plastic, viscoelastic, and viscoplastic systems are discussed. The new approach is contrasted with some presently accepted procedures based on the self-consistent and Mori—Tanaka approximations, which are shown to violate exact relations between local and overall inelastic strains.


Author(s):  
L. Schillemans ◽  
D. Van Hemelrijck ◽  
F. De Roey ◽  
I. Daerden ◽  
F. Boulpaep ◽  
...  

2006 ◽  
Author(s):  
Caglar Oskay ◽  
Jacob Fish

We present a new computationally efficient mesoscale model aimed at predicting the dominant characteristics of failure at the microstructural level. This method combines the multiple scale asymptotic expansion method with the generalized transformation field analysis (GTFA) to reduce the computational cost of the direct homogenization approach. A computational validation methodology was devised for the validation of the proposed mesoscale model against experimental data. The proposed validation methodology permits incorporation of various types of experiments to the validation process by employing an experiment simulator repository.


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