This test rig from CFM Schiller for the civil aviation industry is designed for testing of wings and their components, in this case for the Airbus A350 XWB. The tests can be carried out both statically and dynamically. These development and certification tests are applied for qualification of parts for the production process. Loadings that act upon the wingtip and winglet structures during service life are simulated with this full scale test rig.
The relevant types of loading are bending, torsion, and a combination of both types. Loading is applied by 15 hydraulic actuators, which adapt the specimen via a special interface at certain predefined locations. Each of the 5 yokes holds 3 actuators. In order to achieve unfalsified measurement results, the weight of the yokes is compensated by the so called counter balance system, using wire ropes, pulleys, and counter weights.
The specimen is mounted on the highly stiff strong wall, which weighs approx. 17 tons. Brackets on the strong wall serve as adapter interfaces. They are customized for every individual specimen.
The GVT air spring system units simulate the dynamic behavior of the aircraft under flight conditions, while the plane can remain on the ground. This allows the executions of a modal analysis of the aircraft. The GVT serves to prove and validate FEM calculations of the aircraft structure. Each air spring system unit is carried out as a welded framework, which comprises a hydraulic lifting mechanism, an adapter spindle with integrated load cell, air springs, and a pneumatic level control system.
The hydraulic lifting mechanism operates at the jacking points of the aircraft and lifts it until the landing gear loses contact to the ground. During the ground vibration test, the aircraft rests on the integrated air springs. The system features two possible natural frequencies: 1.6 Hz and 0.9 Hz. The lower natural frequency is achieved by connecting additional volumes to the air spring system. The air spring system units are flexibly movable on caster wheels and can thus be positioned exactly below the aircraft’s jacking points. The hydraulic actuators with the adapter spindles carry the entire load of the aircraft during lifting and testing.