Title :
Monitoring screws under tensile load using acoustic emission analysis
Author :
Hänel, Volker ; Thelen, Wolfgang
Author_Institution :
Inst. of Meas. & Control Technol., Tech. Univ. Berlin, Germany
fDate :
4/1/1996 12:00:00 AM
Abstract :
The acoustic behaviour of screws under applied load was examined to develop an in-process monitoring system for endangered screw connections. In order to apply load to a screw, a hydraulic tensile testing machine was designed. Signals occurring during tensile tests were digitally recorded and analyzed using an acoustic emission (AE) technique. An increase of the AE-rate at the yield limit and weaker AE-activity during plastic deformation were found. The AE-signals contained dominant frequencies in two narrow frequency ranges, at 590 kHz and 1010 kHz, which made it possible to distinguish between friction processes in the screw thread and abrupt dislocation processes under load. The significance of the results for in-process monitoring of screws is illustrated
Keywords :
acoustic emission testing; hydraulic systems; mechanical testing; monitoring; plastic deformation; tensile testing; 1010 kHz; 590 kHz; abrupt dislocation processes; acoustic behaviour; acoustic emission analysis; acoustic emission technique; data analysis; dominant frequencies; friction processes; hydraulic tensile testing machine; in-process monitoring; load; pipe line; plastic deformation; screws monitoring; steel; stress strain curve; tensile load; weaker AE-activity; yield limit; Acoustic emission; Acoustic testing; Fasteners; Flanges; Frequency; Monitoring; Oscilloscopes; Plastics; Signal analysis; Yarn;
Journal_Title :
Instrumentation and Measurement, IEEE Transactions on
