Strength design of premium threaded casing connection

'Micro-Meso-Process Theory' for Fatigue Source Evolution in Metallic Parts

“…The relationship between fatigue limit and tensile yield strength [3,8] The fatigue limit of metal in common sense is actually the surface fatigue limitσ Ws , which is always lower than the its yield strength. While, there should be relationship between the internal fatigue limit σ Wi and the yield strength, because their essence are closed.…”

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This paper is an overview of our previous works [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. A "micro-meso-process theory" [1,3,7] for quantitative analyses of the critical conditions of fatigue source evolution in metals and metallic parts has been established under comprehensive considerations of the processes occurring in individual weak grains (called as "micro-processes") and the cooperative processes occurring in their surrounding grains (called as "meso-processes"), as well as the macro-scopical features of the fatigue behaviour.

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Obtaining and Predicting of Equivalent Load Spectrum for Overhead Traveling Crane Based on Support Vector Machines

“…Through the survey in crane accident, found that its primary cause is the endurance failure [1].So, most government and the scientific research institution began to research the crane' endurance failure question massively，Hope that report the user before equipment endurance failure. Precondition for solving the crane endurance failure is that establishes real service condition of simulating the crane metal structure, the representative typical load--time course, namely load spectrum [2].As a result of load randomness and the uncertainty, the actual result is unable to apply directly in the theoretical analysis and the project practice, but need to construct equivalent load spectrum which can reflect naturally the time variation of the crane structure system under each kind of operating mode.…”