13th International Conference on Fracture June 16-21, 2013, Beijing, China methods to calculate accurate values are presented. An analytical extension method and the extrapolation of singular stresses and strains on the crack faces provide very good results for straight and curved cracks. The Jk-integral is applied to multiple crack systems, calculating a global value of Jk, being the sum of all local values related to every single crack tip. Auxiliary conditions are introduced to solve a global minimization problem. A separation procedure enables to calculate loading quantities related to each crack tip. Based on the specimen in Fig. 7, experiments are about to be carried out, in order to verify the theoretically predicted crack patterns. References [1] R. S. Barsoum, On the use of isoparametric finite elements in linear fracture mechanics. Int J Numer Methods Eng, 10 (1976) 25-37. [2] D. Bergez, Determination of stress intensity factors by use of path-independent integrals. Mech Res Commun, 1 (1974) 179-180. [3] P. O. Bouchard, F. Bay, Y. Chastel, I. Tovena, Crack propagation modelling using an advanced remeshing technique. Comput Methods Appl Mech Eng, 189 (2000) 723-742. [4] G. P. Cherepanov, Mechanics of brittle fracture, McGraw-Hill, New York, 1979. [5] J. W. Eischen, An improved method for computing the J2 integral. Eng Fract Mech, 26 (1987) 691-700. [6] J. D. Eshelby, The force on an elastic singularity. Solid State Phys, 3 (1956) 79-144. [7] M. Gosz, J. Dolbow, B. Moran, Domain integral formulation for stress intensity factor computation along curved three-dimensional interface cracks. Int J Solids and Struct, 35 (1998) 1763-1783. [8] M. Gosz, B. Moran, An interaction energy integral method for computation of mixed-mode stress intensity factors along non-planar crack fronts in three dimensions. Eng Fract Mech, 66 (2002) 299-319. [9] R. D. Henshell and K. G. Shaw, Crack tip finite elements are unnecessary. Int J Numer Methods Eng, 9 (1975) 495-507. [10] A. G. Herrmann, G. Herrmann, On energy release rates for a plane crack. J Appl Mech, 48 (1981) 525-528. [11] P. O. Judt, A. Ricoeur, Accurate loading analyses of curved cracks under mixed-mode conditions applying the J-integral. Submitted to Int J Fract. [12] J. R. Rice, A path independent integral and the approximate analysis of strain concentration by notches and cracks. J Appl Mech, 35 (1968) 379-386. [13] M. Stern, E. B. Becker, R. S. Dunham, A contour integral computation of mixed-mode stress intensity factors. Int J Fract, 12 (1976) 359-368. [14] S. S. Wang, J. F. Yau, H. T. Corten, A mixed-mode crack analysis of rectilinear anisotropic solids using conservation laws of elasticity. Int J Fract, 16 (1980) 247-259. [15] M. L. Williams, On the stress distribution at the base of a stationary crack. J Appl Mech, 24 (1957) 109-114. [16] G. Zi, J.-H. Song, E. Budyn, S.-H. Lee, T. Belytschko, A method for growing multiple cracks without remeshing and its application to fatigue crack growth. Model Simul Mater Sci Eng, 12 (2004) 901-915. -10-
RkJQdWJsaXNoZXIy MjM0NDE=