A new type of flat-bar specimen for non-proportional mixed-mode crack tip loading under uniaxial tension. (15th March 2019)

• Record Type: Journal Article
• Authors: Ricoeur, Andreas; Judt, Paul; Piffer, Benedict
• Is Part Of: Engineering fracture mechanics. Volume 209(2019)
• Page Start: 382
• Page End: 391
• Publication Date: 2019-03-15
• Subjects: Flat bar-core specimen (FBC-specimen) -- Non-proportional loading -- Crack deflection -- Uniaxial tension; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2019.02.016
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: A new specimen allows for non-proportional loading of cracks by uniaxial tension. The new specimen covers a wide range of mixed-mode parameters. The specimen is easily manufactured and the testing requires just simple equipment. Crack deflection under non-proportional loading can efficiently be investigated. Abstract: Non-proportional cyclic loading is a challenging issue for numerical crack path predictions. Principal stress axes and the vector of the J -integral rotate during loading and the mixed-mode ratio of stress intensity factors changes within a load period. Reliable criteria for crack deflection, accounting for arbitrary loading and boundary conditions under non-proportional loading, have not yet been found. Experimental research in this field nowadays requires expensive set-ups and multiaxial testing equipment such as hydraulic biaxial or tension-torsion testing machines. In this paper, a specimen is presented, suitable for uniaxial testing, however providing conditions of non-proportional loading. Finite element simulations show that the variance of mixed-mode parameters is sufficiently large to cover the range of K II / K I -ratios required for investigating crack deflection criteria.