On the solution of unstable fracture problems with non-linear cohesive laws

• Type: Article in International Scientific Journal
• Date: 2024

Authors

de Carvalho, MV (Author) Other; Lopes, IAR (Author) FEUP; F.M. Andrade Pires (Author) FEUP

Journal

Title: Engineering Fracture Mechanics

Vol. 295

ISSN: 0013-7944

Publisher: Elsevier

Indexing

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Other information

Authenticus ID: P-00Z-ESH

DOI: 10.1016/j.engfracmech.2023.109736

Abstract (EN): Fracture mechanics models have well-known numerical challenges when implemented within implicit quasi-static frameworks once the cumulative internal energy exceeds the capacity for dissipation through the fracture process. Although this finding has been mainly reported for linear softening traction-separation laws, this work comprehensively explores non-linear softening behaviours and proposes a more general instability criterion. The ratio of cohesive to internal power emerges as a crucial factor. As a result, even scenarios involving a single cohesive element undergoing monotonic loading may exhibit a limit point at any stage of crack propagation, not just during crack initiation. Two strategies for handling fracture problems with instabilities within an implicit solution are discussed: an arc-length technique and an extension of quasi-static formulation into a dynamic regime. A comparative assessment is performed, covering both simple single-element cases and more complex scenarios. Furthermore, the study delves into more intricate material responses, including transformation-induced plasticity effects. Notably, incorporating these dissipative phenomena in the bulk material mitigates the difficulties associated with snap-back-like behaviours.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 27