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The battlefield environment, external vibration load condition is complex, in the process of vehicle and shooting, random vibration and impact load can lead to car sight structure stress and strain of the primary mirror, will affect the performance of the vehicle sights. Aimed to study the vibration impact load of car mirror, the influence mechanism, the paper designed the experimental study of on-board sights that modal experiment, sine scanning, random vibration and impact. To improve the environment of on-board sight reliability and performance is of great significance. 1. Primary mirror experimental modal analysis 1.1 Vibration load conditions A sinusoidal scanning mirror, random vibration and impact are provided by vibration table, can be adjusted through the shaking table controller excitation amplitude and frequency, vibration experiment is divided into sine scanning experiment, random vibration experiment and impact. 1.2 Laboratory equipment The experimental modal analysis of the main equipment include: automotive sights primary mirror, piezoelectric acceleration sensor, data acquisition system and force hammer. Experimental data acquisition system, can achieve 16 channels synchronous sampling, the highest use frequency of 256 kHz/channel. Experimental force hammer head material can be adjusted, covering different frequency width of pulse excitation, meet the requirement of different frequency response, and is suitable for small and medium-sized structure mode excitation. 1.3 Experiment method The experimental analysis includes dynamometry and contingency force method. Of dynamometry according to different incentives divided into hammer excitation method and the vibrator excitation method, hammer excitation method is divided into SIMO, MISO and partitioning integrated mode, and vibrator excitation method is divided into SIMO and pure mode. According to the input signal in a different way, the unexpected force method is usually divided into work incentives and environmental incentive method, experiment using hammer excitation incentives, simulation environment for high frequency response, select stainless steel hammer random excitation. To obtain accurate experimental data. Experiment selected 28 points for the reference point, make the 7 batches, each batch use six sensors to collect 6 point signal, each batch sensor measuring point number as shown in table 1. 4th International Conference on Machinery, Materials and Computing Technology (ICMMCT 2016) © 2016. The authors Published by Atlantis Press 515 Tab. 1 Each batch sensor bonding point Batch measuring point |
