WEB Modeling the influences of corrosion-induced hydrogen production on the fatigue life of clinched jointsTuesday (22.09.2020) 12:05 - 12:20 Z: Special Symposia II Part of:
Corrosion has a major influence on the lifetime of particular clinched joints. When designing or improving joining processes, the material degradation caused by corrosion has to be taken into account with respect to the load-bearing capacity of the joint. Corrosion usually causes metals to either dissolve into an electrolyte or build some form of protective oxide layers (e.g. aluminum oxide or copper oxide). These oxide layers have other material properties than the metal and might be damaged during the joining process. The damaged oxide layer exposes the metal surface to the electrolyte and thus leads to corrosive effects. Within these mechanisms, molecular hydrogen can be produced in acidic regimes at the metal acting as the cathode. When the joined components are subjected to mechanical stresses (e.g. through cyclic loading), damage accumulates in the material caused by occurring plastic and elastic strains. The amount of strain a material can endure until failure depends on many factors but is heavily influenced by material degradation. Additionally, molecular hydrogen can be absorbed by the metal and consequently causes embrittlement. Experiments which are usually used to determine the corrosion fatigue damage often run for long periods of time. Numerical simulations can help a great deal in predicting the corrosion fatigue life of a clinched joint in a reasonable time. In order to capture the aforementioned effects, a sophisticated modelling approach is necessary. Challenges lay within the combination of different involved fields and their respective space and time scales. A first modeling approach of selected phenomena such as hydrogen absorption and diffusion into an arbitrary metal is given. In the present research, first results for a reduced fatigue life of a metal specimen under uniaxial cyclic loading are shown.