Abstract:

In this paper, the distribution of axial stress at the cross-section of an enter-gas nozzle of main landing gears and the distribution of circumferential stress at a screwed hole of the enter-gas nozzle are investigated by using photoelasticity. The stress intensity factor KI of an enter-gas nozzle containing semi-ellipic crack is also investigated by using both photoelastic and acoustic technique. The former experimental results are in agreement with analytical results. The difference between the latter experimental techniques is within 10 percent. This is satisfactory in engineering use. The values determinated by the experiments are lower than the ultimate values σb and KIc of the material used in the design of the landing gear. Therefore, The landing gear redesigned is rational and safe.

Key words: main landing gear, enter-gas nozzle, stress