This paper reports on an attempt to systematically re-interpret the conventional multiaxial fatigue criteria in terms of the Theory of Critical Distances: in the present study the criteria proposed by Crossland, Dang Van, Papadopoulos, Matake, McDiarmid, respectively, and the so-called Modified Wöhler Curve Method were considered. The procedure devised to re-interpret the above methods in terms of the Theory of Critical Distances was based on the following two assumptions: (i) the critical distance is a material constant to be determined under fully-reversed uniaxial fatigue loading; (ii) the presence of non-zero mean stresses as well as of non-zero out-of-phase loading has to be directly taken into account by the fatigue damage parameters themselves. The constants depending on the material fatigue properties of every considered criterion were re-calculated by considering a cracked plate subjected to Mode I as well as to Mode III loading. The systematic application of the proposed procedure proved the fact that only the critical plane approaches can coherently be re-formulated in accordance with the Theory of Critical Distances. Finally, to check the accuracy of such criteria in predicting fatigue limits of notched components several experimental results, generated under both uniaxial and multiaxial fatigue loading, were selected from the technical literature. This validation demonstrated that the most accurate critical plane approach is the Modified Wöhler Curve Method, giving predictions mainly lying within an error interval of 20%, independently of geometrical feature and degree of multiaxiality of the stress field in the fatigue process zone.
Can the conventional High-Cycle Multiaxial Fatigue Criteria be re-interpreted in terms of the Theory of Critical Distances?
SUSMEL, Luca;
2006
Abstract
This paper reports on an attempt to systematically re-interpret the conventional multiaxial fatigue criteria in terms of the Theory of Critical Distances: in the present study the criteria proposed by Crossland, Dang Van, Papadopoulos, Matake, McDiarmid, respectively, and the so-called Modified Wöhler Curve Method were considered. The procedure devised to re-interpret the above methods in terms of the Theory of Critical Distances was based on the following two assumptions: (i) the critical distance is a material constant to be determined under fully-reversed uniaxial fatigue loading; (ii) the presence of non-zero mean stresses as well as of non-zero out-of-phase loading has to be directly taken into account by the fatigue damage parameters themselves. The constants depending on the material fatigue properties of every considered criterion were re-calculated by considering a cracked plate subjected to Mode I as well as to Mode III loading. The systematic application of the proposed procedure proved the fact that only the critical plane approaches can coherently be re-formulated in accordance with the Theory of Critical Distances. Finally, to check the accuracy of such criteria in predicting fatigue limits of notched components several experimental results, generated under both uniaxial and multiaxial fatigue loading, were selected from the technical literature. This validation demonstrated that the most accurate critical plane approach is the Modified Wöhler Curve Method, giving predictions mainly lying within an error interval of 20%, independently of geometrical feature and degree of multiaxiality of the stress field in the fatigue process zone.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
