Application And Research Of Fiber Optic Acoustic Emission Monitoring System For Large Cranes

The large crane machinery is widely used in China’s heavy industryapplications. A large number of crane machinery have complex structure, whichmake security incidents increasingly frequent due to bearing a lot of risk factorsand overloaded work. Routine testing detection is time-consuming to make thecranes stop work. The key parts of structural damage is difficult to detect in atimely manner, which cause the crane machinery will still be a major accident atruntime after passing the test. It is urgent to resolve the problem of cranemachinery real-time monitoring. For this demand, this paper introduces cranemachinery local damage monitoring system based on the fiber optic acousticemission sensor. Carry out experimental verification and monitoring methodologies. This relays on the quality control public welfare industryresearch projects.Firstly, this paper summarizes the major structural damage modes of cranemachinery, including corrosion, fatigue cracks and weld defects. This takes thePortal cranes for example. Compare the current detection methods, then find thatthe problems faced by remote monitoring. Introduce acoustic emission detectionprinciple and fiber optic transmission technology，summarize the main craneacoustic emission source. On this basis, present the details of optical fibersensing monitoring system based on acoustic emission.Then the system uses a piezoelectric acoustic emission sensor for signalacquisition, through the front-end amplifier for signal amplification, in order tomake the analog signal convert to a standard signal which can be received by theA/D chip. Use acoustic emission card to conduct the feature extraction andwaveform acquisition. Finally transmit the data through the fiber to the PCsoftware for data processing and display. The designed system can make stablelong-distance transmission, and alarm in the abnormal state with signal acquisition and real-time analysis. Alert the operator stop to check maintenancetimely, reduce the accident rate.Finally, use the developed system to make a pilot study. We make the Q235steel tensile test and a large component bearing load test in the laboratory. Bycontrast, verify the ideas’ feasibility and the reliability of the monitoring system.And moreover, carry out the practical application and obtain preliminary desiredresults in the field.