The Effect Of Fatigue Life Of Shaft By Notch Geometric Parameters

Natural Science Foundation of Gansu Province in funding for the axes in the entire life cycle of the fatigue that often appear in the issue,carried out the notch geometry parameters on fatigue life of shaft impact study to seek to establish the impact of the unified description of fatigue life to provide the design parameters basis and theoretical basis.Based on the fatigue strength of the theory of system parameters on the notch geometry of the impact of fatigue life.Discussion of the fatigue life prediction of local stress-strain method,combined with multiaxial fatigue life prediction of thought, to such effect has been to damage parameter of fatigue life prediction model. Discussed the finite element analysis of axial shaft in the basic methods and analysis, using ANSYS software to establish a notch shaft in the establishment of three-dimensional solid model axis,loading solution was reversed under the conditions of the gap near the roots of the local stress-strain distribution.Consider a round-axis radiusρof the notch,the notch depth h and the opening angleαof the notch and other parameters were the root of stress and strain analysis.Select Von.Mises equivalent stress for this article studied the notch-shaft fatigue life damage parameter,combined with finite element analysis results under the proportional constant amplitude load fatigue life calculation of the notch shaft.The results show that:the notch shaft fatigue life increases with the increase of radiusρ,with the notch increasing depth h reduced;whenρand h fixed,the notch opening angleαof the shaft fatigue life of a small degree of influence.When a/b=0.5 in the sameρ/h,with the deviation angleβincreases,the notch-shaft fatigue life of a downward trend;when p/h≥0.2,the impact of notch-shaft fatigue life is a major factor in deviation angle.Identified notch to reverse the effects of load parameter description.With non-dimensional stress intensity factor as a design basis for the discussion of the notch opening angleαof the non-dimensional stress intensity factor of the impact of the law.The results show that:For the parabolic notch axis to reverse the problem, whenρ/h less,αto f_a(a/b)on the impact of the more remarkable.In this paper,the results of research notch for the establishment of a unified model of modern design foundation.