PSI - Issue 14

N. Venkateswaran et al. / Procedia Structural Integrity 14 (2019) 627–633 N.Venkateswaran/ Structural Integrity Procedia 00 (2018) 000–000

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the Gunner’s main sight which is for monitor the Gunner LOS continuously by the Commander. The existing CCS in the tank is CRT monitor type, and it weighs 7.5 kg which is fitted with the mounting bracket having weight of 7 kg. It was planned to conduct the vibration analysis. Subsequently the level of vibration on all the locations were recorded and analyzed for various operating track profile which are used for the tank testing. The spectrum plot of CCS location for all these track profiles viz., bump, cross country and 2 patterns of the Sine wave shows the overall vibration levels in the frequency band of 20- 2000Hz, are well within the qualified limit of 6.76gRMS (0.04g2/Hz). However, the CCS Electronics unit (LRUs) show a resonance at 22.5 Hz in the lower frequency band where the amplitude is maximum may be of concern for LRUs mal functionality. The existing CCS is being replaced with the indigenous unit. Hence a new CCS unit of LCD type, light weight compact and durable is planned to retro fitment with the new modified rigid compact mounting bracket on AFV. The best suitable design of mounting bracket is validated by estimating the natural frequency and the stress through this Finite element analysis. 2. Literature survey Singiresu S. Rao (2005) has explained analytically to find the stress distribution when the component is subjected to Shock load. The measurements made on the vehicle at various locations by expert team recorded during trail run conducted on various testing tracks as in the internal report (2016) provides the vibration data. This helped the designer to select the suitable choice of the mounting bracket. ABAQUS (2014) presented the methodology for carrying out the shock analysis. 3. Mounting bracket The new mounting bracket, having a overall size of 260x205x30mm, made of mild steel plate thickness of 5 mm and two stiffeners (3 mm) are welded on it. Another one pad is also welded to the mounting bracket top plate. Necessary holes are provided in the bracket for fixing this bracket on the turret roof and fixing the CCS unit on it. Figure 1 shows the solid model of the mounting bracket with CCS unit on it. The mounting bracket weighs 1.6 kg. The CCS electronic unit is mounted on the four holes with the suitable fasteners. The whole assembly CCS unit with the mounting bracket is mounted on the roof of the turret of Armoured fighting vehicle.

Fig. 1. Solid model of Assy. Mounting Bracket & with CCS