Modal Analysis of Vehicle-borne Sights Based on ANSYS

Abstract

According to static load standards and requirements of the vehicle sights mechanical structure, the paper makes the analysis of the structure characteristics of vehicle-borne sights, builds three-dimensional model of vehicle sights in UG and finite element model of the primary reflector in ANSYS. The theoretical modal analysis and experimental modal analysis of the primary reflector are carried out based on vibration testing requirements for the dynamic load, and the results are compared between the two methods. The result of theoretical modal analysis could meet the engineering accuracy requirements. The research provides more convincing evidence for the optimization design of primary reflector structure parameters, also provides an effective tool for the anti-vibration design of primary reflector. Introduction Armored fighting vehicles and tanks are important equipment on battlefield; its effectiveness consists of three factors: firepower, mobility and protective ability. Fire control system is the precise fire weapon system of armored fighting vehicles, mainly includes tracking guidance aiming mirror system, fire control computer system and gun control subsystem. As the part of tracking guidance sight system, sight is divided into upper reflector stabilized sight and lower reflector stabilized sight. In order to improve the battlefield survivability and fire fighting ability of the armored fighting vehicles and tanks, it requires that the armored vehicle is able to observe, aim and shoot perfectly in the complex battlefield, so the study of tracking guidance aiming mirror subsystem received widespread attention. Paper [1] aimed at the stabilization problem of the Low-Light-Level image in bottom-reflecting fire control system, a novel real-time high-precision electronic image stabilization system based on a gyroscope and block matching algorithm was proposed. Its overall structure was designed; the transformation equations between the carrier movement and image movement were derived on the basis of perspective imaging model; the image motion model and the gyroscope signal calibration method were given also. Paper [2] aimed the complex structure on the observation equipment, so the staff cannot offer the technical guarantee for new equipment. Mathematical tools are used to express optical components imaging laws; it studied the fretting theory and builds the fretting model. With the computer simulation technology, combined with optical fretting theory and practical problems, it produced a set of simulation software and showed the influence of optical parts fretting. Paper [3] based on an optical collimator, the focal length of CCD optical system was measured and the system accuracy was analyzed. Results showed that the test method is accurate and reliable and detection precision is high, for high precision sights. The test provided a method for testing the sight-line alteration of high precision sighting telescopes. The study above mainly focused on the theoretical analysis, the actual equipment experiments are of high cost. The paper mainly uses the UG NX 6.0 to build primary reflector model and ANSYS to mesh and make modal analysis, in order to understand the vibration characteristics of upper reflector stabilized sight; we make the simulation analysis, which provides a reference for the further research. International Conference on Information Sciences, Machinery, Materials and Energy (ICISMME 2015) © 2015. The authors Published by Atlantis Press 1497 Introduction of vehicle-borne sight As shown in Fig.1, it is the structure diagram of armored vehicles upper reflector stabilized sight, position torque motor and resolver are mounted on the Y axle, pitch control liquid floated gyroscope is mounted on the X axle, and honeycomb primary reflector is mounted on J axle. Liquid floated gyroscope is a sensitive element, which can detect the angular alteration of X axle and Y axle, the angular signal can adjust and amplify the control system, and then drives torque motor on the X axle and Y axle to maintain stability, and rotates J axle through mechanical transmission, so as to achieve the purpose of stabilizing sight line [4]. Control System Reflector T he T ur re t A rm or Objectiv e Group The Eyepiece Y