Study of Vibration Specifications of a Three-axle Truck Using Lagrange Method

Document Type: Research Paper


1 PhD Candidate at Florida International University, Department of Mechanical and Material Engineering

2 MSc student at Amirkabir University of Technology, Department of Mechanical Engineering

3 Assistant Professor at ShahidRajaeeUniversiy of Tehran, Department of Mechanical Engineering


In this research, Ride quality of a three-axle truck is investigated to understand its vibration specifications and influence of it on special load. The truck is Benz 2624, and the load is rather sensitive to vibrations. The system is considered for an off-road duty. Hence, the vehicle is modeled as a nineteen-degree of freedom system and its equations of motion are derived by employing Lagrange equation. Since, the physical parameters of the vehicle were not available; the truck is modeled in Solidworks CAD software in order to obtain the material and dynamic properties of each component of the truck. Then, a code is developed in MATLAB to calculate natural frequencies and mode shapes of the truck and their corresponding vibrating components in critical speed. A simple model of the truck in ADAMS is employed for validation. The adoption of the results verifies the equations. The developed model can also be used in newer truck with some modifications. It is also necessary to have accurate data for input information in order to change the
current model for other utilities.