ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract A growing fatigue crack is known to be retarded on application of an overload cycle. The retardation may be characterized by the total number of cycles involved during retardation, ND and the retarded crack length, aD. The loading variables play an important role to influence the retardation behaviour and thereby the retardation parameters ND and aD. The important loading variables are considered to be the stress intensity range, ΔK during constant amplitude loading, stress ratio, R and the ratio of the overload stress to the maximum stress in constant amplitude loading, OLR etc. The objective of the present investigation is to study the effect of different loading variables on the retardation parameters. The investigation has been conducted in a 2024-T3 Al-alloy with centre crack tension panels loaded using an Electromagnetic Resonance Machine. The crack extension and crack closure have been measured during cyclic loading under constant amplitude and under overloading situations. The results do indicate dependence of crack opening stress intensity factor, KOP on loading variables such as ΔK, R and OLR. The delay cycle ND is found to increase with loading variables ΔK, OLR and R. The functional dependence of retardation zone aD on loading variables has also been identified.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1004624213382
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