Vibration fatigue

About: Vibration fatigue is a research topic. Over the lifetime, 3460 publications have been published within this topic receiving 46297 citations.

Fatigue failure in random vibration and accelerated testing

Abstract: Accelerated testing involves testing a product at a level higher than the normal usage level. This is important because test time and expenditure for testing can be greatly reduced by accelerated t...

Shear Fatigue Simulation of RC Beams Subjected to Fixed Pulsating and Moving Loads

Abstract: The fatigue behavior of RC beams subjected to moving loads is experimentally investigated. Analytical scrutiny is made on the shear fatigue behavior of RC beams subjected to moving loads based on strain path and time dependent fatigue constitutive models rooted in the multi-scale fixed four-way crack modeling of concrete. Moving load is found to cause dramatic reduction in fatigue life of RC beams as compared to that of the fixed pulsating load both in the experiment and analysis. The mechanism for the reduced fatigue life under moving loads in RC beams is discussed in contrast to that of RC slabs. A simplified relation for the prediction of fatigue life under moving load is proposed for practical use on the basis of standard shear fatigue design equation of JSCE code, used for fixed fatigue loading. The effect of randomness in the position of loading is examined and its implication for the reliability of current fatigue life assessment method of RC members is put forward. The applicability of the multi-scale computational platform is verified for the fatigue investigation of RC beams subjected to moving loads.

New Method for Concurrent Dynamic Analysis and Fatigue Damage Prognosis of Bridges

Abstract: A new methodology for concurrent dynamic analysis and structural fatigue prognosis is proposed in this paper. The proposed methodology is on the basis of a novel small time scale formulation of material fatigue crack growth that calculates the incremental crack growth at any arbitrary time within a loading cycle. It defines the fatigue crack kinetics on the basis of the geometric relationship between the crack tip opening displacement and the instantaneous crack growth rate. The proposed crack growth model can be expressed as a set of first-order differential equations. The structural dynamics analysis and fatigue crack growth model can be expressed as a coupled hierarchical state-space model. The dynamic response (structural level) and the fatigue crack growth (material level) can be solved simultaneously. Several numerical problems with single degree-of-freedom and multiple degree-of-freedom cases are used to show the proposed methodology. Model predictions are validated using coupon testing data from open literature. Following this, the methodology is demonstrated using a steel-girder bridge. The proposed methodology shows that the concurrent structural dynamics and material fatigue crack growth analysis can be achieved. The cycle-counting method in the conventional fatigue analysis can be avoided. Comparison with experimental data for structural steels and aluminum alloy shows a satisfactory accuracy using the proposed coupled state-space model.