Search Results

A capacitance sensor has been developed for measuring the protrusion of fastener heads. The capacitance sensor is easily integrated into an automated rivet installation system. The sensor is capable of measuring the protrusion of a fastener head relative to the skin surface, even in the presence of corrosion protective films used on the aircraft skin surface during manufacture. This paper presents a brief review of the capacitance measurement method. The mechanical design and operation of the sensor are presented as well as information regarding the integration of the sensor within an automated riveting system. Another novel capacitance-based inspection system has been developed for characterization of critical fastener dimensions. Design, capabilities, and inspection data obtained with the fastener measurement system are presented.

An automated drilling and fastening system is under development at the GEMCOR Engineering Corporation for wing manufacture on a new commercial airframe program. It is the first time that cold-working and hole inspection have been integrated into an automated fastener installation system. Numerical control and monitoring of all process parameters have been integrated in the system to achieve the greatest degree of accuracy and repeatability in fastener installation and to provide real-time, in-process statistical quality control. An integral component of the system is a capacitance probe used to measure the diameter and profile of drilled holes. Measurement information obtained with the hole probe is used to monitor the drilling process and predict tooling wear. This paper briefly discusses fastener hole requirements and the effects of hole quality on fatigue life. An overview of the capacitance measurement technique is also presented.