Natural frequency and transient dynamic analysis of vehicle integrated RBS 70 NG system

Sammanfattning: Abstract This study is a master thesis in mechanical engineering at Karlstad’s University that treats operation disturbances that occur during the use of a vehicle integrated air-defense system called Robot-system 70 New Generation (RBS 70 NG) in cooperation with SAAB Dynamics AB. RBS 70 NG is a man-portable air-defense system (MANPADS) which is designed for anti-aircraft warfare and can be used in all climate zones.  The system usually operates on a hard surface such as gravel or hard soil, but for this project the aim is to integrate the system to operate on a vehicle platform. There are two disturbing factors that could affect the system during operation; the first is that the system is displaced due to the external forces that act on the system during use. The second disturbance specification is that the natural frequency of the entire system should be within a range of 3.5-6 Hz for vehicles installed RBS 70 NG [1]. The system is studied by using a simple mathematical model and by the use of computer aided software programs including CATIA V5 R22 and ANSYS R18.1. The modified design of the complete system showed that by adding four external legs to the platform, a natural frequency in-between the given interval is reached. A Transient Response Analysis was done to analyze the MANPADS ground version in order to make have some sort of a reference when studying the vehicle version of the RBS 70 NG and to make both system as similar as possible. The displacement of the system sight was similar for both versions of the system, when operating on the ground and on a vehicle.