The non-proportionality of local stress paths in engineering applications
Journal Title: Frattura ed Integrità Strutturale - Year 2016, Vol 10, Issue 37
Abstract
A scalar measure, which describes the non-proportionality of local stress paths in engineering applications, is introduced. For this purpose the moment of inertia approach by Meggiolaro is modified in a way that the stress time history is evaluated in a tresca-stress-space. This modification makes the non-proportionality factor invariant with respect to the coordinate system. An optimization procedure is implemented to derive a test set-up for new component tests with 2 load channels. The aim of the planned tests is to get a high non-proportionality at the potential crack initiation site. It is not possible to obtain a high non-proportionality factor at the failure location without selective weakening of the component (housing of a rear axle steering). Therefore specific areas of the structure are cut out and the optimization procedure is repeated. As a result of the optimization a test set-up with high local non-proportionality at the potential crack initiation site is achieved for the weakened structure. Another set-up with slightly less non-proportionality but with a very localized damage is derived. This set-up is preferred, because of the robustness in the physical test.
Authors and Affiliations
C. Riess, M. Obermayr
Keywords
Related Articles
- EP ID EP90755
- DOI 10.3221/IGF-ESIS37.08
- Views 72
- Downloads 0
Duplex S-N fatigue curves: statistical distribution of the transition fatigue life
In recent years, very-high-cycle fatigue (VHCF) behavior of metallic materials has become a major point of interest for researchers and industries. The needs of specific industrial fields (aerospace, mechanical a...
Analysis of crack-tip plastic zone in a Compact Tensile Shear (CTS) Specimen
The minimum plastic zone radius (MPZR) criterion is one of the recent criterions to estimate crack initiation direction under mixed mode loading. The MPZR theory is based on the theoretical computations of plastic zone s...
Variation of Stress intensity factor and elastic T-stress along the crack-front in finite thickness plates
Non-singular terms in the series expansion of the elastic crack-tip stress fields, commonly referred to as the T-stress. The T-stress is as an additional stress field characterizing parameter to stress intensity factor (...
Crack mode and life of Ti-6Al-4V under multiaxial low cycle fatigue
This paper studies multiaxial low cycle fatigue crack mode and failure life of Ti-6Al-4V. Stress controlled fatigue tests were carried out using a hollow cylinder specimen under multiaxial loadings of λ=0, 0.4,&nb...
Thermal stress analysis of different full and ventilated disc brakes
During the braking phase, the heat produced by friction between pads and disc cannot be entirely dissipated. Consequently, the brake disc, especially if very hard braking occur, can accumulate large amounts of&nbs...