Like many manufacturing sectors, the aerospace industry is progressively automating its production and the riveting process is no exception. A multitude of rivets are employed to assemble aircraft and spacecraft frames. They serve as the ideal joint in an industry that designs components as lightweight as possible for applications where reliability and safety matter. Given that the riveting process is partially completed robotically, it’s imperative to have quality assurance and control procedures in place to comply with increasingly stringent safety standards.

No process is exempt from defects, and regular inspection at every stage of the riveting process is required to verify or take corrective measures. A common defect in aging aircraft is the nucleation of cracks from rivet holes. Current non-destructive testing (NDT) techniques include eddy current testing (ECT). Determining the integrity of rivet structural assemblies using this method is quite time consuming when you consider the volume of rivets requiring analysis by an advanced technician, making ECT also user dependent.

With a mandate to push the limits of NDT technology forward by constantly innovating, Eddyfi Technologies now offers a better solution using eddy current array (ECA). This solution is faster, more efficient, and the reliable choice for inspecting rivet holes. Our ECA technology enables high resolution scans of complete rivet hole surfaces in a single pass, so technicians can easily and confidently identify any defects. This technology is also directly applicable for general fastener hole inspection.

Figure 7 2D 3D C-scan and Lissajous views of signal defect 1

During the development of this solution, challenges to overcome were negotiating the varying tight internal diameter (ID) rivet hole geometry, and the fact that EC inspection is very sensitive to edge effects and gap irregularities between material layers. Differential mode is an ideal topology for ECA applications where variations in surface must be null without impacting performance on flaws. This mode provides a high Signal-to-Noise Ratio (SNR) by reducing and eliminating background noise signals. We adapted the mechanical probe design and differential topology to produce a multi-element probe dedicated for rivet hole inspection. A probe shoe with a spring-loaded mechanism conforms to the ID and surface conditions, and the probe rotates 360 degrees to cover the entire length required in one pass.

Rivet-Hole-Inspection-Probe-Eddyfi-01This powerful probe paired with the Reddy® eddy current acquisition unit and Magnifi® GO software forms the ideal system for fastener and rivet hole inspection. With multiple setup wizards and analysis tools, inspectors can confidently trust the 2D and 3D C-scan imaging and automatic defect detection tool. We’ve made it even easier: the software automatically creates a comprehensive report detailing all indications for electronic data recording and complete traceability.

Rivet Hole Inspection Complete Inspection Solution

Taking advantage of our expertise in ECA, Eddyfi Technologies presents the better solution for rivet and fastener hole inspection that offers high performance and lower inspection costs. We help keep all stakeholders of the aerospace sector safe. Contact us to learn more today.