An Armoured Fighting Vehicle (AFV) is a cross-country vehicle, which needs to be designed to operate under sever conditions. The vehicle has to negotiate through all surfaces during actual operation at high speeds. Due to the movement of the vehicle, if the loads applied to the road wheels of the AFV were transmitted directly to the chassis, not only would it occupants suffer severely but also its structure would be subjected to an excessive degree of fatigue loading. A very fundamental requirement of high wheel travel, high energy to be stored can be easily achieved with a non linear characteristics suspension system like Hydro Gas Suspension System (HGSS) which is highly compact and having inbuilt damper. Ever though the design is highly complicated, the system can absorb maximum energy, making the ride of the vehicle highly comfortable. The HGSS also ensures the suspension system is soft at lower loading and stiffer at higher loading which cannot be achieved by any linear characteristics suspension system.
A non-linear HGSS has been designed and developed for application in a combat vehicle. The development carried out to facilitate high wheel travel both in the rebound and the bump conditions. Extensive computer modeling and analysis of twenty technical parameters which affect the design and the technical performance of HGSS were carried out on the computer using ‘C’ language programming and using analytical geometry principles to optimize the parameters. The system has been fabricated and subjected to detailed testing on the rig. The system has been engineered successfully and mounted on the vehicle and is under actual technical and field evaluation.
For any class of vehicle and for any number of road wheel stations, an attempt has been made to have the advantages of purely non linear technical performance characteristics HGSS, “The state of the Art” technology available in the world to the vehicle. There was a requirement to have a high wheel travel in rebound condition as well as in bump condition. There are 20 technical parameters, which affect the performance characteristics of the suspension system. A detailed design and analysis were carried out to find the effect of change of each parameter value on acquiring feasible solutions and also to optimize the design. The complete performance characteristics of the suspension system were theoretically predicted. The HGSS was developed and rig tested for different strokes (different loading conditions) at different frequencies to authenticate the design and finally the endurance life of the HGSS was proved on test rig. Having completed the design, analysis, development and rig testing, the same design philosophy can be adopted for any automobile vehicle to increase the ride comfort and higher mobility of the vehicle.