Sage Journals: Discover world-class research

Abstract

Micromechanical models for a study of nonlinear viscoelastic (NVE) response of composite laminae are developed and their performance compared. A single integral constitutive law proposed by Schapery and subsequently generalized to multiaxial states of stress is utilized in the study for the matrix material. This is used in conjunction with a computationally facile scheme in which hereditary strains are computed using a recursive relation suggested by Henriksen. Composite response is studied using two competing micromodels, a simplified square cell model (SSCM) and a finite element based self-consistent cylindrical model (FECM). The algorithm is developed assuming that the material response computations are carried out in a module attached to a general purpose finite element program used for composite structural analysis. It is shown that the SSCM as used in investigations of material nonlinearity can involve significant errors in the prediction of transverse Young’s modulus and shear modulus. The errors in the elastic strains thus predicted are of the same order of magnitude as the creep strains accruing due to viscoelasticity. The FECM on the other hand does appear to perform better both in the prediction of elastic constants and the study of creep response.

Keywords

composites visco-elasticity nonlinearity creep micro-mechanics modeling

Get full access to this article

View all access options for this article.

References

Lou, Y.C. and Schapery, R.A. (1971). Viscoelastic Characterization of Nonlinear Fiber-reinforced Plastics , Journal of Composite Materials, 5: 208-234 .

Schapery, R.A. (1974). Viscoelastic Behavior and Analysis of Composite Materials, In: Sendeckyij, G.P. (ed.), Composite Materials 2, Academic Press, New York .

Schapery, R.A. and Sicking, D.L. (1995). On Nonlinear Constitutive Equations for Elastic and Visco-elastic Composites with Growing Damage, In: Bakker, A. (ed.), Mechanical Behavior of Materials, pp. 45-76, Delft University Press, Delft, Netherlands .

Schapery, R.A. (1969). On the Characterization of Nonlinear Visco-elastic Materials , J. Polymer Eng. Sci., 9: 295 .

Henriksen, M. (1984). Nonlinear Viscoelastic Stress Analysis - A Finite Element Approach , Computers & Structures, 18(1): 133-139 .

Lai, J. and Bakker, A. (1996). 3-D Schapery Representation for Nonlinear Visco-elasticity and Finite Element Implementation , Computational Mechanics, 18: 182-191 .

Schaffer, B.G. (1980). Nonlinear Visco-elastic Behavior of a Composite Material using a Finite Element Micro-mechanical Analysis, MS Thesis, University of Wyoming.

Schaffer, B.G. and Adams, D.F. (1981). Nonlinear Viscoelastic Analysis of a Unidirectional Composite Material , Journal of Applied Mechanics, 48: 859-865 .

Hori, M. and Nemat-Nasser, S. (1999). On Two Micro-mechanics Theories for Determining Micro-macro Relations in Heterogeneous Solids , Mechanics of Materials, 31: 667-682 .

10.

Li, S. (2000). General Unit Cells for Micro-mechanical Analysis of Uni-directional Composites , Composites, Part A: Applied Science and Manufacturing, 32: 815-826 .

11.

Xia, Z. , Zhang, Y. and Ellyin, F. (2003). A Unified Periodical Boundary Conditions for Representative Volume Elements of Composites and Applications , International Journal of Solids and Structures, 40: 1907-1921 .

12.

Jadhav, V.R. and Sridharan, S. (2002). Micro-mechanical Modeling of Polymer based Unidirectional Composites: Use of Bulk Properties of Matrix with Smeared Cracking Model , Journal of Composite Materials, 36(24): 2735-2765 .

13.

Jadhav, V.R. and Sridharan, S. (2003). Prediction of Nonlinear Behavior of Composites via Micro-mechanics Using Matrix Bulk Properties , AIAA Journal, 41(11): 2229-2238 .

14.

Jadhav, V.R. (2000). Micro-mechanical Analysis of Unidirectional Composites, DSc Thesis, Washington University in St. Louis.

15.

Sridharan, S. and Jadhav, V.R. (1997). A Comparative Study of Square Cell and Circular Cell Micro-models , Journal of Composite Materials, 31(15): 1507-1533 .

16.

Jadhav, V.R. and Sridharan, S. (1999). A Comparative Study of Micro-models for Nonlinear Analysis of Laminae , Journal of Composite Materials, 33(18): 1667-1684 .

17.

Muliana, A. and Haj-Ali, R. (2004). Integrated Micromechanical - Structural Models for Long term Behavior of FRP Composite Structures” , In: 45th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, 19-22 April, 2004, Palm Springs, California.

18.

Aboudi, J. (1990). Micro-mechanical Characterization of the Nonlinear Viscoelastic Behavior of Resin Matrix Composites , Composites Science and Technology, 38: 371-386 .

19.

Sung, Yi , Ahmad, M.F. and Hilton, H.H. (1998). Nonlinear Viscoelastic Stress Singularities near Free Edges of Unsymmetrically Laminated Composites , International Journal of Solids and Structures, 35: 321-327 .

20.

Aboudi, J. (1991). Mechanics of Composite Materials: A Unified Micro-mechanical Approach, Elsevier, New York .

21.

Hashin, Z. and Rosen, B.W. (1964). The Elastic Moduli of Fiber-reinforced Materials , Journal of Applied Mechanics, 31: 223-232 .

Nonlinear Viscoelastic Analysis of Composites using Competing Micromechanical Models

Abstract

Keywords

Get full access to this article

References