How hidden 3D structure within crack fronts reveals energy balance

Wang, Meng; Adda-Bedia, Mokhtar; Kolinski, John M.; Fineberg, Jay

doi:10.1016/j.jmps.2022.104795

Cited by 9 publications

(8 citation statements)

References 66 publications

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“…Therefore, this experimental method can be readily adopted for similar characterization in other soft materials [72][73][74][75][76]. This analysis may be applied to questions in fundamental fracture mechanics, including fully 3D crack perturbations [78][79][80][81], 3D crack path selection criteria [82][83][84][85][86], the kinematics of crack surface patterns [16][17][18][19][20][21][22][23][24][25][26][27], and crack stability under mixed-mode loading conditions [29,[63][64][65][66][67][68].…”

Section: Discussionmentioning

confidence: 99%

“…Within this small region, however, the deformation can be extremely large under the diverging stresses; this large deformation can lead to nonlinear material responses [5][6][7], and further induce cohesive loss or poroelastic solvent flux [8][9][10][11][12][13][14][15]. Furthermore, LEFM is developed for predominantly planar cracks that are translationally invariant along z, but a real crack can be complex with 3D features [16][17][18][19][20][21][22][23][24][25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

“…For soft materials such as hydrogels, the large deformation results in a exaggerated crack opening [30][31][32] before fracture, introducing large geometric nonlinearity by local material rotation, despite the experimental merits of hydrogels as a proxy brittle material for fundamental fracture studies [25][26][27][33][34][35][36][37], and relevance as a bio medical material [38,39]. While the incompressible neo-Hookean constitutive law is frequently used as the constitutive model for PAAm hydrogels in many fracture experiments [8,[16][17][18]21,[25][26][27], the stress-induced swelling in polymeric hydrogels is well-known [11,[40][41][42][43][44][45][46][47][48] and confirmed for PAAm hydrogels in uniaxial, biaxial, and indentation experiments [49][50][51]. Indeed, most of these studies use similar poroelastic models to those used broadly in the earth sciences [52][53][54][55][56].…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the dependency of the solvent flux on crack velocity and the steadiness of the crack speed are discussed. Our experimental methods can be readily extended to 3D complex crack investigations [16][17][18][19][20][21][22][23][24][25][26][27][28][29][63][64][65][66][67][68][69][70][71], even in other material systems [72][73][74][75][76].…”

Section: Introductionmentioning

confidence: 99%

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3D characterization of kinematic fields and poroelastic swellingnear the tip of a propagating crack in a hydrogel

Li,

Zubko,

Delespaul

et al. 2024

Preprint

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In fracture mechanics, polyacrylamide hydrogels have been widely used as a model material for experiments, benefited from its optical transparency, fracture brittleness, and low Rayleigh wave velocity. To describe the brittle fracture in the hydrogels, linear elastic fracture mechanics comes as the first choice. However, in soft materials such as hydrogels, the crack opening can be extremely large, leading to substantial geometric nonlinearity and material nonlinearity at the crack tip. Furthermore, poroelasticity may also modify the local mechanical state within the polymer network. Direct characterization of the kinematic fields and poroelastic effect at the crack tip is lacking.Here, based on a hybrid method of digital image correlation and particle tracking technique, we retrieved high-resolution 3D particle trajectories near the tip of a slowly propagating crack and measured the near-tip 3D kinematic fields, including the displacement fields, rotation fields, stretch fields, strain fields, and swelling fields. Results confirmed the complex multi-axial stretching near the crack tip and the substantial geometric nonlinearity, particularly on the two wakes of the crack where rotation exceeds $30^{\circ}$. Comparison between the measured and predicted displacement and strain fields, derived from linear elastic fracture mechanics, highlights a disagreement in the direct vicinity of the crack tip, particularly for displacement component $u_x$ and through-thickness strain component $\varepsilon_{zz}$. Significant swelling, due to the poroelastic solvent migration, is also observed, with a strong correlation to the local stretch. Our experimental method, without any assumption of the material properties, can be readily extended to study 3D crack tips in a huge varieties of materials, and our results can shed light on the fundamental fracture mechanics and the development of material models for soft materials undergoing large multi-axial loading and substantial swelling.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

3D characterization of kinematic fields and poroelastic swellingnear the tip of a propagating crack in a hydrogel

Li,

Zubko,

Delespaul

et al. 2024

Preprint

View full text Add to dashboard Cite

show abstract

“…The fracturing process varies significantly between samples, reflecting the acute sensitivity of crack formation and propagation on the random imperfections in the hydrogel and the complex topography arising from previous fracturing. 36–38…”

Section: Methodsmentioning

confidence: 99%