Accumulated fatigue damage self-diagnosis system for railway steel truss bridge node

Abstract

The invention discloses an accumulated fatigue damage self-diagnosis system for a railway steel truss bridge node. When a train boards a bridge, a stress response time-history signal of a middle cross section of a truss rod piece which is connected with the tested node when the train goes by is automatically acquired through a strain sensor; a bending moment and shaft force time-history conversion module converts the stress response time-history signal into a bending moment and shaft force time-history signal; a dynamic stress analysis module takes a node welding residual stress field which is determined according to a construction process of a node welding line as an initial stress field, and superposes a node train traveling dynamic stress field which is determined by the bending momentand shaft force time-history signal to obtain the position of a most dangerous point and the strain state of the bridge node welding line; and finally, a fatigue accumulation analysis module determines the fatigue damage accumulation degree of the most dangerous point when the train goes by according to the position of the most dangerous point and the strain state and the strain fatigue critical surface method, and then a man-machine interaction interface informs a user of the fatigue damage accumulation degree. Therefore, the system can automatically inform the user of fatigue information ofthe welding line of the railway steel truss bridge node in time so as to repair the railway steel truss bridge in time and guarantee the safety of the railway steel truss bridge.

Description

technical field [0001] The invention relates to the field of bridge structure engineering, in particular to a self-diagnosis system for cumulative fatigue damage of railway steel truss bridge nodes caused by train running. Background technique [0002] Railway steel truss bridge is a common type of railway bridge. Since the running of railway trains is a periodic long-term action, it will cause the cumulative fatigue damage of the overall nodes of the truss structure, especially the joint welds. Considering that fatigue damage is a cumulative effect, the overall joint weld has no symptoms during the whole process from the beginning of damage accumulation to the initiation of cracks, so the failure of the overall joint weld, that is, the initiation of joint cracks, cannot be known in advance When will it happen, so it is impossible to warn in time and fix it in time. [0003] For this reason, it is necessary to provide a self-diagnosis system for cumulative fatigue damage o...

AI Technical Summary

Problems solved by technology

Considering that fatigue damage is a cumulative effect, the overall joint weld has no symptoms during the whole process from the beginning of damage accumulation to the initiation of cracks, so the failure of the overall joint weld, that is, the initiation of joint cracks, cannot be known in advance When will it happen, so it is impossible to warn in time and fix it in time

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