Study Of Mechanical Dynamic Performance For Aircraft Driving Mechanism With Computer Aided Design

Driving mechanism is the key part of flight control system for air vehicle, which is the main transmission form of the primary control surface of modern medium and small-sized air-transport, and its dynamic behaviors directly affect the flight and safety performances. The development of computer aided design (CAD) technique has the great significance of engineering application and valuable prospect in improving the predictability of systematic design, as well as reducing research period and cost, etc. In order to meet the requirement of the design diversity and analyses to dynamic quality, this thesis has developed an integrated CAD software platform to visually design the primary driving mechanism and estimate the dynamic quality. It has been shown that the software operations and numerical results reach its design objective on the whole. The main research work of the thesis is as follows:The thesis has reviewed the Hamilton's variational principle and numerical algorithms of finite element method (FEM) to elastic dynamics, and for the mechanical driving system, some highly cost effective FEM computational techniques are analyzed and discussed, meanwhile, the related differential algorithm of large-scale ordinary differential equation group with its numerical stability, and contact algorithmic theory, etc. have also been introduced;The thesis has elaborately studied and discussed the basic characteristics of the conventionally mixed type driving components of aircraft, and correct selections to their analytical element patterns for simulating the pulley-cable mechanism. Some numerical examples have demonstrated the reasonableness to use the elements SHELL163 and LINK167 in ANSYS software package for modeling to pulley-cable mechanism;Based on the study and application of computer-aided design software technology, this thesis has presented a complete software design method to implement the parameterized numerical modeling to the mechanical driving system, that is, using ANSYS/APDL language to compile command template base for pulley-cable system. With help of the C++ Builder integrated development environment, all main visual window bodies and sub-procedures of the CAD software have been developed and coded for interactive interface to input mechanical driving components, and for data processing to compile and link numerically computational command stream templates, etc. A visual CAD software platform has been run, which integrates multiple visually parameterized modeling to driving mechanisms, numerical analysis of systematic dynamic simulation, and plentiful pre- and post-processing.Through some large-scale engineering examples, the reasonableness and effectiveness of the methodology and techniques proposed in the thesis have been shown, and the technical serviceability of the integrated platform for real-world mechanical driving system of aircraft has also been demonstrated. Key words: mechanical driving mechanism, dynamic performance, parameterized modeling, finite element simulation, computer aided design software...