Analysis Of Static And Dynamic Characters Of Circumferential Flex Track Drillins System

Automatic drilling on large parts of the aircraft is a key technology concerning about the quality, efficiency and life of aircraft assembly. It has been an important factor during the assembly procedure.Take the butt section of fuselage as an example, there are many problems during the drilling work, such as wide drilling area, large numbers of drilling holes (more than6000) and usually difficult to drill. Due to the above reasons, Zhejiang University proposed a lightweight, portable, automated NC machine-Circumferential Flex Track Drilling System, which is based on flex track drilling technology. The paper mainly finishes the analysis of the equipment’s mechanical structure, static and dynamic characteristics.First of all, the automatic drilling technology’s development and application are summarized. And so are the equipments. After analyzing the development of flex track drilling technology, Circumferential Flex Track Drilling System is established in order to realize automatic flexible drilling efficiently. The system integrates the technology of NC, laser measurement and off-line programming.Based on the practical requirement of drilling on the circle area of fuselage butt section, the functional and technical proposal of the system is proposed. Its components’structure and working flow are introduced in detail.In order to satisfy the automatic drilling system’s requirements analysis, a kinematics model based on Denavit-Hartenberg method is established. The kinematics Jacobi Matrix are solved by vector product method and verified by differential transform method. Then the system’s kinematic characteristic is analyzed.Finally, the whole equipment’s finite element model is established by ABAQUS. Then the pre-tightening force to locate the equipment is calculated. After analyzing the deform of the circumferential track, a new locating method to improve drilling accuracy is proposed. Then the dynamic analysis is performed. Modal analysis of the system gets15order natural frequency and vibration mode. Harmonic response analysis in harmonic force gets the maximum displacement under each direction. So the weak parts can be found to optimize the structure’s design and improve the dynamic characteristics of the Circumferential Flex Track Drilling System.