Variational principles of nonlinear fracture mechanics

SummaryA variational principle of total energy is formulated for finite strain statics of a hyperelastic body whose initial configuration contains a gap. From this principle statical equations and boundary conditions for the gapped body are derived. The equilibrium condition at a gap tip is associated with the well-knownJ-integrals. By including the reaction of inertia and the flux of kinetic energy the principle of total energy is transformed to the variational inequality of evolution for dynamics of a hyperelastic body with a propagating crack. A closed system of dynamical equations, boundary conditions and additional conditions on the unknown contact crack surfaces and crack tip is obtained. As example the antiplane shear of an infinite gapped body is considered.

[1]  J. Lions,et al.  Inequalities in mechanics and physics , 1976 .

[2]  Equilibrium Criterion for a Nonlinear Elastic Slited Body , 1989 .

[3]  G. Herrmann,et al.  Energy Release Rates and Related Balance Laws in Linear Elastic Defect Mechanics , 1987 .

[4]  J. Rice A path-independent integral and the approximate analysis of strain , 1968 .

[5]  L. B. Freund,et al.  Energy flux into the tip of an extending crack in an elastic solid , 1972 .

[6]  G. P. Cherepanov Crack propagation in continuous media , 1967 .

[7]  M. Gurtin,et al.  On the energy release rate in elastodynamic crack propagation , 1980 .

[8]  R. Russo On the dynamics of an elastic body containing a moving crack , 1986 .

[9]  R. Batra The force on a lattice defect in an elastic body , 1987 .

[10]  H. Stumpf Dual extremum principles and error bounds in nonlinear elasticity theory , 1978 .

[11]  E. Sanchez-Palencia Non-Homogeneous Media and Vibration Theory , 1980 .

[12]  C. Truesdell,et al.  The Non-Linear Field Theories Of Mechanics , 1992 .

[13]  James K. Knowles,et al.  An asymptotic finite-deformation analysis of the elastostatic field near the tip of a crack , 1973 .

[14]  A. A. Griffith The Phenomena of Rupture and Flow in Solids , 1921 .

[15]  Localized shear discontinuities near the tip of a mode I crack , 1987 .

[16]  James K. Knowles,et al.  The finite anti-plane shear field near the tip of a crack for a class of incompressible elastic solids , 1977 .

[17]  J. D. Eshelby The Continuum Theory of Lattice Defects , 1956 .

[18]  M. Williams,et al.  On the Stress Distribution at the Base of a Stationary Crack , 1956 .

[19]  Variational Inequalities in Brittle Fracture Mechanics , 1989 .

[20]  Morton E. Gurtin,et al.  On the energy release rate in quasi-static elastic crack propagation , 1979 .

[21]  A. G. Herrmann Material momentum tensor and path-independent integrals of fracture mechanics , 1982 .

[22]  J. L. Sanders On the Griffith-Irwin Fracture Theory , 1960 .

[23]  I. N. Sneddon The distribution of stress in the neighbourhood of a crack in an elastic solid , 1946, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.