Method for estimating remaining fatigue life of main metal structure of crane

Abstract

The invention relates to a method for estimating the remaining fatigue life of a main metal structure of a crane. The method is applied to the compiling of actually measured load spectrums, the measurement of material fatigue crack propagation curves, the nondestructive detection of hazardous locations and the estimation of the remaining fatigue life of the main metal structures of the large cranes at relatively higher working levels in shipyards, ports and the like, and is also applied to the estimation of the remaining fatigue life of the cranes of other types. The method comprises the following steps of: (1) acquisition of the load spectrum; (2) measurement of material performance; (3) detection of an initial crack location and an initial crack size; (4) acquisition of a crack stress intensity factor; and (5) estimation of the remaining fatigue life. In the method, factors such as the existence of a crack in the structure, the detection of the location and size of the actually crack, and the like are taken into account, and the nondestructive detection is performed on the hazardous location; therefore, the remaining fatigue life of the metal structure of the crane can be accurately estimated.

Description

technical field [0001] The invention relates to a method for estimating the remaining fatigue life of the main metal structure of a crane, which is suitable for the compilation of the actually measured load spectrum, the determination of the fatigue crack growth curve of the material, the non-destructive detection of dangerous positions and Estimation of the remaining fatigue life of the main metal structure, this method is also applicable to the estimation of the remaining fatigue life of other types of cranes. Background technique [0002] Large cranes in ports and shipyards are mainly gantry cranes, shipbuilding gantry cranes, shore bridge cranes, etc. They are the main lifting equipment for port loading and unloading operations, with short, repetitive, periodic cycles, frequent starting and braking Due to the large impact load and other working characteristics, during the design service life, various forms of cracks often appear on the stressed components due to fatigue....

AI Technical Summary

Problems solved by technology

The Paris fatigue crack growth rate equation mainly characterizes the stable crack growth stage, but does not consider the threshold value, fracture toughness and average stress on the fatigue crack growth rate.

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