Numerical investigation of a slider canopy locking mechanism

Canopy locks are the basis of flight safety. It is essential to prevent plastic deformation during flight, the expected maximum elastic deformation within acceptable limits and adjustability capabilities for different tolerance situations for canopy locking mechanisms. In this study, four different designs of PH13-8Mo (AMS 5629) were considered. The first design, which is the fixed locking structure was compared with three different designs designed at different eccentricity levels and numerically examined. First, a fixed and traditional pin design was modelled by using CATIA software. Then an eccentric pin design was considered to provide an adjustable solution with the same dimensions. After the design stage, to obtain displacement and stress the finite element analysis was performed using ANSYS software. In this first step, the necessary displacement and stress values could not be obtained in the structure. For this reason, some improvements at the connection points of the pin support were accomplished and a double wall housing structure was designed. After realizing that the designed double walled pin housing reduced the displacement and stress values, an extended double walled eccentric pin housing was designed by expanding the wall gaps as an alternative. As a result of the analysis, it was observed that the highest displacement and stress values took place in the eccentric pin structure of the single-support wall . Although the fixed pin structure demonstrated better structural properties than the single support wall eccentric pin structure, it did not present as low as stress and displacement performance as the double supported pins. It was seen that the preference for double supported eccentric pin structures in similar locking mechanisms reduces the loads on the pin and pin body and reduces the expected displacement values in the structure. Keywords: Canopy, mechanism design, eccentric pins, PH13-8Mo, finite element method, stress