Tytuł pozycji:
Laboratory investigations on landing gear ground reactions (load) measurement
Ground reaction measurement in landing gear laboratory tests is used in order to gain knowledge about loads transferred to the aircraft structure. Ground reaction level is defined during aircraft design phase and it is required not to exceed limit value in real construction. Load from landing affect directly strength of aircraft structure especially mounting points what translates both strength of aircraft structure especially mounting points what translates both on safety and weight of the final design. Meeting the safety requirements is crucial in aviation regulations conformity. Landing gear ground reactions evaluation is performed during laboratory tests in order to meet the compliance with the ground load requirements assumed in design phase. Proper test method is crucial to prove the actual load. One of the methods is landing gear dynamic drop test where landing forces are measured. Force measurement is made in several ways according to test stand construction and test object specifics. In this article, three methods are described due to author’s experience in landing gear tests. Proposed techniques cover two direct and one indirect force measurements. Direct approach is based on strain gauge measurement principle. One is a strain gauge plate fixed to the ground while the second one is based on strain gauges attached to landing gear mounting nodes. Indirect approach is based on the acceleration of the tested object, which by definition is correlated with the force applied to the structure. Obtained test results allow determining the kinetic energy absorbed by landing gear during drop test. In this article author also presented numerical integration of the time history data and compared them with simulation results in order to show equivalence of all three of the test methods and to prove correctness of the test initial conditions determination.
Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę (zadania 2017).
