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Non-local damage model based on displacement averaging. (English) Zbl 1140.74533

Summary: Continuum damage models describe the changes of material stiffness and strength, caused by the evolution of defects, in the framework of continuum mechanics. In many materials, a fast evolution of defects leads to stress-strain laws with softening, which creates serious mathematical and numerical problems. To regularize the model behaviour, various generalized continuum theories have been proposed. Integral-type non-local damage models are often based on weighted spatial averaging of a strain-like quantity. This paper explores an alternative formulation with averaging of the displacement field. Damage is assumed to be driven by the symmetric gradient of the non-local displacements. It is demonstrated that an exact equivalence between strain and displacement averaging can be achieved only in an unbounded medium. Around physical boundaries of the analysed body, both formulations differ and the non-local displacement model generates spurious damage in the boundary layers. The paper shows that this undesirable effect can be suppressed by an appropriate adjustment of the non-local weight function. Alternatively, an implicit gradient formulation could be used. Issues of algorithmic implementation, computational efficiency and smoothness of the resolved stress fields are discussed.

MSC:

74R05 Brittle damage
74S05 Finite element methods applied to problems in solid mechanics
Full Text: DOI

References:

[1] Krajcinovic, The continuous damage theory of brittle materials, Journal of Applied Mechanics 48 pp 809– (1981) · Zbl 0468.73124
[2] Vakulenko, Continuum theory of medium with cracks (in Russian), Mekhanika Tverdogo Tela (4) pp 159– (1971)
[3] Chaboche, Number 295 in Col. Euromech 115 pp 737– (1979)
[4] Eringen, On nonlocal plasticity, International Journal of Engineering Science 19 pp 1461– (1981) · Zbl 0474.73028 · doi:10.1016/0020-7225(81)90072-0
[5] Eringen, Theories of nonlocal plasticity, International Journal of Engineering Science 21 pp 741– (1983) · Zbl 0519.73024 · doi:10.1016/0020-7225(83)90058-7
[6] Pijaudier-Cabot, Nonlocal damage theory, Journal of Engineering Mechanics 113 pp 1512– (1987) · Zbl 0788.73012
[7] Bažant, Why continuum damage is nonlocal: justification by quasi-periodic microcrack array, Mechanics Research Communications 14 pp 407– (1987) · Zbl 0666.73067 · doi:10.1016/0093-6413(87)90063-2
[8] Bažant, Nonlocal continuum damage, localization instability and convergence, Journal of Applied Mechanics 55 pp 287– (1988) · Zbl 0663.73075
[9] Saouridis C Identification et numérisation objectives des comportements adoucissants: Une approche multiéchelle de l’endommagement du béton 1988
[10] Bažant, Measurement of characteristic length of nonlocal continuum, Journal of Engineering Mechanics 115 pp 755– (1989)
[11] Pijaudier-Cabot, Finite element analysis of bifurcation in nonlocal strain softening solids, Computer Methods in Applied Mechanics and Engineering 90 pp 905– (1991) · doi:10.1016/0045-7825(91)90190-H
[12] Bažant, Why continuum damage is nonlocal: micromechanics arguments, Journal of Engineering Mechanics 117 pp 1070– (1991)
[13] Pijaudier-Cabot, Localization of damage in a nonlocal continuum, Mechanics Research Communications 19 pp 145– (1992) · Zbl 0788.73012 · doi:10.1016/0093-6413(92)90039-D
[14] Saouridis, Prediction of the failure and size effect in concrete via a bi-scale damage approach, Engineering Computations 9 pp 329– (1992)
[15] Pijaudier-Cabot, Strain localization and bifurcation in a nonlocal continuum, International Journal of Solids and Structures 30 pp 1761– (1993) · Zbl 0799.73005 · doi:10.1016/0020-7683(93)90232-V
[16] di Prisco, Crush-Crack: a non-local damage model for concrete, Journal of Mechanics of Cohesive and Frictional Materials 1 pp 321– (1996) · doi:10.1002/(SICI)1099-1484(199610)1:4<321::AID-CFM17>3.0.CO;2-2
[17] Zhixiong, A nonlocal damage mechanics approach to high temperature fatigue crack growth, Engineering Fracture Mechanics 53 pp 535– (1996) · doi:10.1016/0013-7944(95)00156-5
[18] Kennedy, A simple nonlocal damage model for predicting failure of notched laminates, Composite Structures 35 pp 229– (1996) · doi:10.1016/0263-8223(96)00040-2
[19] Rodríguez-Ferran, Error estimation and adaptivity for nonlocal damage models, International Journal of Solids and Structures 37 pp 7501– (2000) · Zbl 0996.74078 · doi:10.1016/S0020-7683(00)00209-2
[20] Jirásek, Consistent tangent stiffness for nonlocal damage models, Computers and Structures 80 pp 1279– (2002) · doi:10.1016/S0045-7949(02)00078-0
[21] Comi, Numerical aspects of nonlocal damage analyses, Revue Européenne des Éléments Finis 10 pp 227– (2001)
[22] Comi, A non-local model with tension and compression damage mechanisms, European Journal of Mechanics - A/Solids 20 pp 1– (2001) · Zbl 0982.74005 · doi:10.1016/S0997-7538(00)01111-6
[23] Benvenuti, A thermodynamically consistent non-local formulation for damaging materials, European Journal of Mechanics - A/Solids 21 pp 535– (2002) · Zbl 1038.74006 · doi:10.1016/S0997-7538(02)01220-2
[24] Borino, A symmetric nonlocal damage theory, International Journal of Solids and Structures 40 pp 3621– (2003) · Zbl 1038.74509 · doi:10.1016/S0020-7683(03)00144-6
[25] Patzák, Adaptive resolution of localized damage in quasibrittle materials, Journal of Engineering Mechanics 130 pp 720– (2004) · doi:10.1061/(ASCE)0733-9399(2004)130:6(720)
[26] Huerta, Lecture Notes in Applied and Computational Mechanics, in: Advanced Mathematical and Computational Geomechanics pp 239– (2003)
[27] Jirásek, Nonlocal models for damage and fracture: comparison of approaches, International Journal of Solids and Structures 35 pp 4133– (1998) · Zbl 0930.74054 · doi:10.1016/S0020-7683(97)00306-5
[28] Jirásek, Rotating crack model with transition to scalar damage, Journal of Engineering Mechanics 124 pp 277– (1998) · doi:10.1061/(ASCE)0733-9399(1998)124:3(277)
[29] Jirásek, Fracture Mechanics of Concrete Structures pp 805– (2001)
[30] Peerlings, Gradient-enhanced damage for quasi-brittle materials, International Journal for Numerical Methods in Engineering 39 pp 3391– (1996) · Zbl 0882.73057 · doi:10.1002/(SICI)1097-0207(19961015)39:19<3391::AID-NME7>3.0.CO;2-D
[31] Geers, On the numerical modelling of ductile damage with an implicit gradient-enhanced formulation, Revue Européenne des Éléments Finis 10 pp 173– (2001)
[32] Engelen, Nonlocal implicit gradient-enhanced elasto-plasticity for the modelling of softening behaviour, International Journal of Plasticity 19 pp 403– (2003) · Zbl 1090.74519 · doi:10.1016/S0749-6419(01)00042-0
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