Green and sustainable engines require accurate and well documented material data for safe operation of the engines at optimum efficiency. The SAGE project aimed at demonstrating open rotor engines and technologies to reduce fuel consumption, weight and increased efficiency of engine components. Structural integrity and safety of engine critical parts had considered with regard to design, manufacturing aspects and in-service maintenance and overhaul.

The engine operating conditions, thermal and mechanical loads, material properties and other influencing parameters were affecting the Approved Life of the component. Extensive analysis, component & engine tests, and inspections during both component manufacturing and in-service had to be performed for verification. In particular, the regulations required for critical parts to fulfil appropriate damage tolerance criteria had to be considered, and the potential for failure from material, manufacturing and service induced anomalies within the Approved Life of the part. This meant that the potential existence of various imperfections, defects and flaws in the component were recognised and are due to material issues, component design and manufacturing. This situation was handled through the incorporation of fracture resistant design, process control and Non-destructive Testing (NDT).

In fabricated components and structures different visual inspection and NDT methods were being used for weld inspection. The quality of the welds determined the fatigue life of a component. This project focused on welds made in IN718, both laser welds and TIG welds. Before testing the specimens were NDT tested (WP2), then high cycle fatigue tested (WP4), creep fatigue tested (WP5), fracture surfaces examined (WP3), statistical analysis performed (WP6) and finally the lifing model developed (WP7). The model was then put to use by the topic manager for design of green and sustainable engines.