Evaluation of the Residual Service Life of Thin-Walled Structural Elements with Short Corrosion-Fatigue Cracks

Generalization of the equivalent area method for the case of short fatigue cracks in a three-dimensional body

“…From relation (11), the value of the initial radius of the equivalent short crack can be obtained [1, p. 87]:…”

“…Then having substituted (22) into the obtained formula for determination of the opening of the fracture process zone in front of a crack contour (18) and having grouped the dimensionless loading values p * /σ t and crack sizes a/a * , we obtain the following expression for the critical loading: In addition, let us conduct a numerical experiment based on the generalized Sack's problem for the steel 65Ã (analogue to 1066) using the proposed formula for determination of the opening of the fracture process zone (19). On Grith's problem, it has been veried [8,11,12] that the approach to present the crack growth rate via the opening in its tip is invariant contrary to the employment of a stress intensity factor. Let us use this approach to Sack's problem for a three-dimensional body.…”

Reliability Estimation of Transport Means Elements Under the Action of Cyclic Loads and Corrosive Environment

“…Nowadays, up to 65% of the mechanisms of transport means elements are known to get out of order under the influence of aggressive (corrosive) environment and mechanical stresses; up to 25% of these mechanisms are broken down due to the overloads caused by strength losses because of corrosion damages [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. According to the data on agrarian production development in Ukraine, the growth of the transportation volumes of chemical and mineral fertilizers [15] is about 2% of all cargoes.…”

“…Delayed spontaneous fracture of structural elements under the action of variable in time (cyclic) loads and corrosive-aggressive environments is relatively continuous but dangerous process because of the low degree of its predictability and diagnosis. Corrosive environments increase the failure probability of metal materials [1][2][3][4][5] during cyclic loading and cause the propagation of corrosion-fatigue cracks. To determine the service life of vehicles constructions elements under the influence of cyclic loads and corrosive environments, the appropriate analytical models should be applied.…”