AUTHORS: Radim Jarkovsky, Pavel Cyrus, Stepan Major
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ABSTRACT: This article is dedicated to modeling and simulation of fatigue degradation of crankshaft. In this article is discussed model of crankshaft which is damaged during its service life. Specially authors consider in their work the fatigue damage influenced by the vibration during traffic. The fatigue damage is considerable problem in engineering and can cause catastrophic accidents, also this accidents can caused fatal injury of personnel. The crankshafts are subjected to the intensive multiaxial loading during its working life and crankshaft failure is much more frequent cause of the accident, during the engine service parts except cylinder rupture. Therefore great effort is devout to the fatigue resistance improvement and proper method of fatigue life modeling. In recent work, relatively new approach for fatigue crack modeling is discussed and its application on specific problem of crankshaft in four cylinder engine. Experimental part of this study is based on measurement of vibration on the crankshaft. The experimental device was used with down-scaled model of engine to reveal influence of vibration. The majority of fatigue crack models are working with predefined boundary length of crack. This length makes possible to distinguish between the different phases of crack growth, i.e. different crack growth mechanism. The method used in this work is based on another approach. The fatigue crack is simulated in this way: (1) the crack grew throughout the whole crankshaft volume controlled by nucleation mechanism, (2) by propagation mechanism. Thus two different fatigue curves are obtained and merged in one final fatigue curve. This method is in compliance with data obtained experimentally
KEYWORDS: Crankshaft, Simulation, FEM model, Fatigue, Modeling, Experimental study
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