Cad Modelling And Virtual Simulation Of An Aircraft Door Mechanism

In this paper the authors explain a methodology to reconstruct a mechanism of an aircraft door and simulate its functioning. Due to its complexity the computer aided simulation (Digital Mock-up) is the only way to evaluate the performances, to check the assembly procedure, to find out possible interferences, and to study the sensitivity of each component to mechanical errors. The complete assembly is made of hundreds of functional parts. Moreover, the whole system is composed of several different mechanisms which interact together during the door opening procedure. All these mechanisms have to work precisely and in cooperation, and the motion of the door is spatial and quite difficult to understand without a three dimensional simulation. The dynamic simulation of the motion has been performed by means of multibody techniques, so it has been possible to evaluate the reaction forces on each joint and characterize the dynamic behaviour of the whole system. The proposed methodology is based on a fully parametric CAD program and it allows to introduce specific variables to simulate mechanical errors in manufacturing or assembling in order to assess their effect on the motion of the door.