The Research On The Mechanical Properties Of A New Rotating Mirror For Ultra-high Speed Camera

Rotating mirror is one of the crucial optical components of the rotating mirror ultra-high speed camera for accelerating. The mechanical properties of rotating mirror directly affect the operational reliability, time resolution and imaging quality of ultra-high speed camera. Because of the high revolution speed, there is a very serious problem in rotating mirror design that the critical speed of rotating mirror affects its mechanical properties. The rotating mirror must have good static and dynamic characteristics in order to have the security and reliability of ultra-high speed. The rotating mirror design method include following several aspects.First, the finite element modal of rotating mirror was established by the ANSYS parameters design language to analysis the static strength of rotating mirror for obtaining the results of the stress and strain under the theory of static strength. The results show that the rotating mirror would not damaged, because the static strength can meet the requirement of design. A modal analysis and harmonic response analysis of rotating mirror were done to analysis the dynamic characteristics of rotating mirror based on the dynamic analysis modal. The results show that the first bending is the main reason for rotating mirror damaged. During the design process, working speed of rotating mirror must stay away from the first bending critical speed. The experiment system of rotating mirror was set up to test the results of modal and harmonic response analysis. Numerical analysis is proved to have the practical feasibility.Second, Combined the method of analysis the large structural dimensions magnesium rotating mirror, analyzes the static mechanical properties of magnesium alloy and radial under actual operating conditions of variable density rotating mirror. When the working speed is 50 × 104 rpm, the maximum stress of magnesium rotating mirror is in the shaft, the maximum stress is 131 MPa, the maximum strain is 2.637 × 10-3, static strength and stiffness of magnesium rotating mirror requirements are met. The Static Strength and Stiffness of the magnesium alloy rotating mirror meet the requirements. The maximum stress of variable density rotating mirror 261 MPa, the maximum strain is 1.642 × 10-3, the deformation of variable density rotating mirror is three-fifths of the magnesium alloy.Third, modal analysis and harmonic response analysis of rotating mirror were done under the working speed. The first critical speed of magnesium alloy and variable density rotating mirror located in a high speed region. Both of them can quickly jump over the resonance point, the size of structure meet the requirements of the dynamic performance.