NON-DESTRUCTIVE TESTING OF IN-SERVICE WOODEN BEAMS

摘要

Wooden utility pole structures are nondestructively tested while in service,inparticular utility pole cross-arms. A helicopter or boom truck brings anoperator to thecross-arm. Manually striking the cross-arm using a hammer or other weight withanattached accelerometer senses and sends a shock wave through the cross-arm.Theshock wave also is sensed using a second accelerometer sensor in a temporarilyaffixed sensor pod at the other end of the cross-arm, or a Itematively, a non-contactradar vibration sensor is trained on a fastener in the cross-arm, to sensevibration fromthe shock wave. Practical aspects include mounting particulars for affixingthe sensorpod against the cross-arm, manipulating the sensor pod at an elevation belowthehelicopter working platform, measurements for dimensions and density, etc. Thedata isreceived at a processor and correlated with structural strength or used torank therelative strength of cross-arms.