L. Biggin, Click Bond, Carson City, NV
Floating nutplates are used extensively in the aerospace industry in regions of the aircraft where either two-sided access is not possible during assembly or where quick access for maintenance is necessary. Examples include external and internal access panels. In the past, these nutplates were riveted to the structure.
This presentation will discuss a new manufacturing process that utilizes adhesive to fasten rivetless nutplates to structure. Adhesive bonded nutplates are used successfully to provide increased structural strength; bonding of the nutplate reduces the stress concentrations by eliminating rivet holes. Bonding also reduces production costs as well as future maintenance and repair costs. The installation utilizes a unique self-fixturing process which maintains accurate position and constant pressure on the joint during adhesive cure.
Large sample size testing has been completed that shows bonded nutplates conform to and exceed the NASM25027 strength requirements. This testing has included accelerated aging and fluid conditioning. Case studies are provided to detail the cost/benefit analysis and show a 75% reduction in manufacturing time when using bonded nutplates in lieu of the traditionally riveted nutplates. Design guidelines are reviewed to ensure proper selection of nutplates and adhesives on the complete range of metal and composite structures.
This innovation in manufacturing process offers the best of all benefits by increasing structural integrity and productivity while decreasing the overall cost of the manufactured component.
Summary: Adhesive bonded nut plates are being successfully used to provide increased structural strength; bonding of the nut plate reduces the stress concentrations by eliminating rivet holes. Bonding also reduces production costs. The installation depends on a unique self-fixturing process which maintains accurate position and constant pressure on the joint during the adhesive cure.
