Authors: Kuniharu Ushijima, Dai Heng Chen, Naoto Kitte

303

Authors: You Tang Li, Zhi Yuan Rui, Chang Feng Yan

Abstract: A uniform model, in which the crack, V-notch, U-notch and arc are described as breach
uniformly, is put forward in this paper. The tip radius, depth and field angle of breach are regarded as
the parameter of annularly breached bar. The stress field and displacement field near the tip of the
annularly breached bar under bending, in which takes fα(a/b) as its descriptive parameter, was given.
All forms of breaches according to the change of tip radius, depth and field angle were discussed. The
effects of parameters on fα(a/b) in bending were analyzed. The criteria for the safety design and
fracture design both of which on fα(a/b) were obtained. The results not only can be applied widely to
anti-fracture design but also be used for reference in anti-fatigued design in product lifecycle
management.

751

Authors: You Tang Li, Ping Ma, Chang Feng Yan

Abstract: A model of notched shaft in which the crack, V-notch, U-notch and arc were described as notch uniformly, was put forward. The stress field near the notch tip of notched shaft was given using quadric coordinate system by selecting an appropriate displacement function at first, and then the stress field in Cartesian co-ordinates system was obtained. The 3-D model was set up and the local stress and strain near the tip of notch was calculated by using finite element software ANSYS, and the effect of notched parameters of shaft on stress was analysed. The results show that there is a small region, in which the effect of the tip radius and depth on the stresses is obviously. The effect of an open angle of notch on stress is very small. The smaller the ratios between the tip radius and depth of notch, the larger the stress concentrations near the tip of notch.

166

Authors: Bo Chen, You Tang Li

Abstract: The tip radius *ρ*, depth t and field angle *α *of notch and the geometrical sizes *a* and *b* of shaft are looked as descriptive parameters in the annular notched shaft. Taken the crack, blunt crack and notch as breach, the stress field and displacement field near the tip of breach which serve dimensionless factor *f*_{α}(a/b) as descriptive parameter are obtained. The effects of parameters *ρ*, t and *α* to *f*_{α}(a/b) are analyzed. The connections between stress intensity factor of crack and stress concentrator factor of notch, between sharp V-notch and crack, between V-notch and U-notch have been founded.

174

Authors: Krzysztof Gołoś, Michał Niepokolczycki

Abstract: FEM linear numerical analysis of stress distribution demonstrated that the model Zappalorto and Lazzarin for analysed V-hole ended notch, relatively correctly predicts the stress distribution at the tip of the notch, especially for small angles of opening. The maximum levels of hoop stress and a tangential for load Mode II strongly dependent on the radius of the notch. The stress reaches its maximum value at a certain distance from the tip of the notch, approximately equal to half of the hole circle radius. The most effective way to reduce the levels of maximum stress at the notch is to increase the radius. When changing radius of 0.5 mm to 2 mm can reduce the degree of stress concentration approx. 40%.

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