Dynamic fracture analysis in quasi-brittle materials via a finite element approach based on the combination of the ALE formulation and M−integral method

Abstract. In this work, a novel multiscale model for softening periodic microstructures is proposed, relying on a nonlinear homogenization method combined with a cohesive/volumetric finite element model. This strategy is able to overcome the mesh sensitivity issues usually experienced by purely volumetric homogenization techniques in presence of strain localization. As the main ingredient of the proposed approach, a microscopically informed traction-separation law for the embedded interfaces is extracted, starting from the homogenized bulk behavior obtained for a suitably chosen Repeating Unit Cell (RUC) subjected to different macro-strain paths. The present approach has been fully validated by performing several numerical simulations of the main damage phenomena experienced by fiber-reinforced composite structures, with special reference to transverse micro-cracking. Finally, to investigate the reliability and the accuracy of the proposed model, a comparison with direct simulations performed on fully meshed specimens has been presented, in terms of both load-displacement curves and associated crack patterns.

Section: Discussionmentioning

confidence: 99%

Multiscale failure analysis of fiber-reinforced composite structures via a hybrid cohesive/volumetric nonlinear homogenization strategy

Gaetano

2023

“…Due to recent advancements in additive manufacturing, numerous researchers are exploring the high potential for designing nacre-like bioinspired materials with advanced properties finding applications in a wide range of engineering fields [6][7][8]. Due to their complex microstructure, composite materials are heterogeneous media that are susceptible to various nonlinear phenomena, especially if subjected to large deformation, such as instabilities at the microscopic and macroscopic scale [9] or damage mechanisms involving the microscopic scale such as matrix cracking or debonding of the fiber-matrix interfaces [10][11][12][13]. It is widely known that there is a strict correlation between these microscopic mechanisms and macroscopic fracture phenomena such as delamination, interfacial debonding, and multiple crack propagation which are generally considered the most frequent precursors of damage in microstructured composites [14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Microgeometrical design of lightweight bioinspired nacre-like composite materials for wave attenuation tuning

Pranno¹

2023

Abstract. Numerical simulations give the opportunity for designing periodic microstructured materials by tuning and manipulating their dynamic properties in terms of vibration control by varying their main micro-geometrical parameters. Specifically, the bandgap formation in 2D nacre-like composites characterized by a brick-and-mortar arrangement of stiff platelets and a soft matrix containing periodically arranged cavities was investigated through the Bloch-wave analysis. The numerical outcomes highlighted that, by varying the microstructural topology of the void inclusions and the stiff platelets, enhanced wave absorption capabilities can be obtained providing new opportunities to design periodic lightweight bioinspired composite metamaterials with elastic wave attenuation properties.

“…However, fracture mechanics-based models result to be very efficient for predicting damage phenomena with a-priori known crack path but provide some divergences with respect to the experimental outcomes, in terms of crack patterns, in the case of unknown crack paths. To overcomes these drawbacks, the moving mesh technique has been recently introduced in the structural mechanics field to easily permit the moving of the computational mesh according to specific conditions [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

A moving cohesive interface model for brittle fracture propagation

Maio

2023

Abstract. In this work, an advanced numerical model, based on the cohesive zone approach and the moving mesh technique, is proposed to simulate fracture propagation in quasi-brittle materials. In particular, the proposed numerical procedure consists of two stages. In the former one, according to the inter-element crack approach, once a suitable stress criterion for fracture onset is satisfied, a mesh boundary, representing the crack segment, is selected and aligned along the crack propagation direction by using the well-known moving mesh technique. In the latter one a zero-thickness interface cohesive element, equipped with a traction-separation law, is inserted on-the-fly along the previously selected mesh boundary, in order to describe the nonlinear fracture process. Comparisons with available experimental and numerical results have highlighted the effectiveness and the reliability of the proposed model in the prediction of the brittle fracture phenomenon.