Experimental analysis of viscoelastic criteria for crack initiation and growth in polymers

Different viscoelastic theories have been applied to characterize the resistance to crack initiation and propagation in the fracture of two poly-diethyleneglicol-bis-allyl-carbonate grades that have different crosslinking densities.Tensile creep compliance curves have been obtained on unnotched specimens, and fracture tests have been conducted on single edge notched specimens loaded in tension at different temperatures and displacement rates.A theory developed by Schapery for linearly viscoelastic materials has been found to be fairly adequate to describe the experimental results obtained, provided that the hypothesis of the yield stress being constant with time is removed. The time-temperature equivalence has also been found to satisfactorily account for the temperature dependence of the fracture resistance at initiation; however, the same did not hold as good for propagation. A simple scheme to analyse fracture data obtained from viscoelastic materials is also proposed.

[1]  R. Frassine,et al.  An application of viscoelastic fracture criteria to steady crack propagation in a polymeric material under fixed deformation , 1990 .

[2]  D. S. Dugdale.  Yielding of steel sheets containing slits , 1960 .

[3]  M. Rink,et al.  On the viscoelastic fracture criteria for polymers: experiments and analysis , 1992 .

[4]  L. V. Nikitin,et al.  Application of the Griffith's approach to analysis of rupture in viscoelastic bodies , 1984 .

[5]  J. Ferry.  Viscoelastic properties of polymers , 1961 .

[6]  Richard Schapery,et al.  A theory of crack initiation and growth in viscoelastic media , 1975 .

[7]  Wolfgang G. Knauss,et al.  Crack Propagation in a Linearly Viscoelastic Strip , 1971 .

[8]  G. I. Barenblatt.  THE MATHEMATICAL THEORY OF EQUILIBRIUM CRACKS IN BRITTLE FRACTURE , 1962 .

[9]  Derivation of crack growth laws for linear viscoelastic solids based upon the concept of a fracture process zone , 1980 .

[10]  R. Christensen,et al.  A theory of crack growth in viscoelastic materials , 1981 .

[11]  Richard Schapery,et al.  A theory of crack initiation and growth in viscoelastic media , 1975 .

[12]  A. Kinloch.  Mechanics and mechanisms of fracture of thermosetting epoxy polymers , 1985 .

[13]  A. A. Kaminskii.  Investigations in the field of the mechanics of the fracture of viscoelastic bodies , 1980 .

[14]  J. Williams,et al.  Applications of linear fracture mechanics , 1978 .

[15]  C. Popelar,et al.  Viscoelastic material characterization and modeling for polyethylene , 1990 .

[16]  W. Döll.  Optical interference measurements and fracture mechanics analysis of crack tip craze zones , 1983 .

[17]  K. Salama.  Advances in fracture research : proceedings of the 7th International Conference on Fracture (ICF7), Houston, Texas, 20-24 March 1989 , 1989 .

[18]  J. G. Williams,et al.  The effect of temperature on the fracture of polycarbonate , 1975 .

[19]  Yiu-Wing Mai,et al.  Advances in Fracture Research , 1997 .

[20]  Richard Schapery,et al.  A theory of crack initiation and growth in viscoelastic media II. Approximate methods of analysis , 1975, International Journal of Fracture.