Fatigue crack paths under the influence of changes in stiffness
Journal Title: Frattura ed Integrità Strutturale - Year 2016, Vol 10, Issue 35
Abstract
An important topic of the Collaborative Research Centre TRR 30 of the Deutsche Forschungsgemeinschaft (DFG) is the crack growth behaviour in graded materials. In addition, the growth of cracks in the neighbourhood of regions and through regions with different material properties belongs under this topic. Due to the different material properties, regions with differing stiffness compared to the base material may arise. Regions with differing stiffness also arise from ribs, grooves or boreholes. Since secure findings on the propagation behaviour of fatigue cracks are essential for the evaluation of the safety of components and structures, the growth of cracks near changes in stiffness has to be considered, too. Depending on the way a crack penetrates the zone of influence of such a change in stiffness and depending on whether this region is more compliant or stiffer than the surrounding area the crack may grow towards or away from this region. Both cases result in curved crack paths that cannot be explained only by the global loading situation. To evaluate the influence of regions with differing stiffness on the path of fatigue cracks the paths and the stress intensity factors of cracks growing near and through regions with differing stiffness are numerically determined with the program system ADAPCRACK3D. Therefore, arrangements of changes in stiffness modelled as material inclusions with stiffness properties different from the base material or modelled as ribs and grooves are systematically varied to develop basic conclusions about the crack growth behaviour near and through changes in stiffness.
Authors and Affiliations
G. Kullmer, B. Schramm, H. Richard
Keywords
Related Articles
- EP ID EP159234
- DOI 10.3221/IGF-ESIS.35.42
- Views 61
- Downloads 0
Modelling of the fracture toughness anisotropy in fiber reinforced concrete
Steel fiber reinforced concrete is potentially very promising material with unique properties, which currently is widely used in some applications, such as floors and concrete pavements. However, lack of robust&nb...
Use of Circumferentially Cracked Bar sample for CTOD fracture toughness determination in the upper shelf regime
In this work, the use of circumferentially cracked bar (CCB) sample to determine material fracture toughness in the upper shelf regime for carbon steels has been investigated. Since high fracture toughness materi...
Near tip strain evolution of a growing fatigue crack
Near tip full-field strains in a growing fatigue crack have been studied in situ using the Digital Image Correlation (DIC) technique in a compact tension specimen of stainless steel 316L under tension-tension cycl...
Thermal degradation in Carrara marbles as the cause of deformation of cladding slabs
Marble slabs, typically used as façade panels to externally cover buildings, might permanently deform after a certain time of environmental exposure. This phenomenon, called bowing, is generally accompanied by a...
Comportamento a fatica dei giunti saldati in funzione della densità di energia di deformazione locale: influenza dei campi di tensione singolari e non singolari
. Il criterio della densità di energia di deformazione (SED) considera un preciso volume di controllo posizionato in corrispondenza del piede o della radice dei cordoni di saldatura, ossia delle zone di possibile innesco...