Computational Simulation and Experimental Results on 3D Crack Growth in a 3PB-Specimen with an Inclined Crack Plane

Abstract

In this paper the rather complex 3D fatigue crack growth behaviour in a 3PB-specimen with an inclined plane of the initial crack or notch is investigated by the aid of the programme ADAPCRACK3D and by application of a recently developed 3D fracture criterion. It will be shown that the computationally simulated results of fatigue crack growth in the FE-model of the specimen are in good agreement with experimental findings for the development of the spatially twisted crack faces in the real laboratory test-specimen. Consequently, also for this case with a rather complex 3D crack growth behaviour, the functionality of the ADAPCRACK3D-programme and the validity of the proposed 3D fracture criterion can be stated.

Computational simulation and experimental findings of three‐dimensional fatigue crack growth in a single‐edge notched specimen under torsion loading

“…The good agreement between the results from both approaches confirms again that the global spatial geometry of the developing crack fronts and crack faces is dominated by the local mechanical loading conditions along the crack front and less influenced by the material properties of the specimens. Similar conclusions can be drawn from other investigations of complex 3D fatigue crack growth in 3PB specimens with slant cracks, which have been performed by Pook 17,18 and by Buchholz et al 41 . for specimens processed from steel, aluminium alloys or PMMA and also for a variety of other materials.…”

“…In this paper, detailed results of a computational simulation of 3D crack growth will be presented with reference to a paper by Buchholz et al 27 . The simulation is based on the FE‐programme ADAPCRACK3D and a maximum principal stress σ′ 1 criterion, which both have been developed and proposed recently at the Institute of Applied Mechanics of the University of Paderborn 28–35 .…”

An X-FEM based framework for 3D fatigue crack growth using a B-spline crack geometry description

“…Nonetheless, Buchholz et al [47] note that previous comparisons between displacement controlled quasi-static tests and fatigue crack growth tests showed nearly identical crack paths for different materials among which PMMA. Figure 14 compares numerically predicted crack fronts obtained using the presented framework and the experimental results presented by Buchholz et al [48]. Here again a qualitative agreement is found, validating the capability of the presented framework to deal with complex 3D fatigue crack growth.…”

“…However, a qualitatively good agreement with the experimental results is undeniable as seen in Figure 12a. A single edge notch (SEN) specimen with a slanted crack subjected to a torsion load is considered, as reported in [48,49]. A drawing of the specimen with dimensions, load and boundary conditions is shown in Figure 13.…”

“…A load ratio R = 0.1 is assumed and a ∆a max = 1 mm is used. Buchholz et al [48] performed an experiment on a PMMA specimen. These experiments only serve a qualitative purpose as the experiment was a displacement controlled quasi-static test, i.e.…”