Detection of Fatigue Cracks in Boom Structures in Large Mining Machinery with Coupled Response Measurements

摘要

Early detection of fatigue cracks in mechanical structures in the large mining machinery is an important concern to mining operators. The ability to identify the crack early is crucial to optimize productivity, reduce maintenance cost and prevent catastrophic failures. This paper presents a potential method for crack detection in welded boom structures based on the coupled response measurements. The coupled response refers to the phenomenon that a cracked structural member demonstrates composite vibration modes (axial and bending) when excited purely laterally. This property is a possible indicator of a crack. Both theoretical explanation and experimental verification are demonstrated. A test rig simulating boom structure was fabricated and fatigue cracks were created by a cyclic loading mechanism. The experimental results suggest that this approach offers a useful tool for routine maintenance work and safety monitoring.