Lockheed Martin and the Danish Technological Institute have established a Residual Stress Center of Excellence in Denmark. The facility will focus on advanced materials characterization and residual-stress analysis to provide detailed data on structural wear. The goal is to help operators determine when specific components require inspection or repair, moving away from reliance on conservative safety margins.
The initiative operates under the Danish-American offset agreement associated with Denmark’s acquisition of the C-130J fleet. Lockheed Martin stated that the cooperation aims to support smarter maintenance and improve reliability for the aircraft while creating jobs in Denmark. The project is designed to build local expertise in advanced materials technology and support exports to international markets.
Current military aircraft maintenance is largely planned around predetermined inspection intervals. The new center seeks to change this by using precise measurements to reflect the actual loads and condition of components. Mikkel Agerbæk, Director at the Danish Technological Institute, noted that the team is linking advanced characterization with operational needs.
He said this shifts maintenance from statistically assessed requirements to actual measurements based on current history.
The research will examine residual stresses around rivet and bolt holes, areas where cracks can develop in aircraft structures. The center will utilize synchrotron and neutron radiation from European research facilities to measure internal stresses without cutting into the metal.
Nikolaj Gersager Henriksen, Business Manager at the institute, explained that these stresses can either inhibit crack formation or increase the risk of damage, playing a central role in determining component longevity.
The project will also investigate the effects of Split Sleeve Cold Expansion, a manufacturing method already used on the C-130J to create compressive stresses around fastener holes. Improved measurements are intended to provide precise evidence of how long this protective effect remains, supporting decisions on inspection intervals.
