Firefighting specialized multi-axle heavy duty vehicles are capable of both off-road and high speed in accordance with the standards they must fullfill. One of the first steps to ensure that these capabilities are possessed is to develop a reliable and long-lasting chassis that is resistant to all these driving conditions. The vehicle chassis working on wide range of different road and load conditions so it must have a wide operating range to cover all conditions. The spring-damper couple, located between the body and axles, transmits the irregular loads coming from the road into regular vibrations, while the shock absorber is responsible for damping these vibrations.
The natural frequency depends on the stiffness and mass of the structure. If a structure is vibrated instantaneously and depending on time while it is at rest, they vibrate at certain frequencies according to the degree of freedom of this structure. Many engineering problems are foreseen by determining the behavior of the mechanical structure according to these mode shapes. Thanks to modal analysis, vibrations in time domain are converted into frequency domain, and more accurate interpretations are made about the vibrations affecting the vehicle throughout its movement.
In this study, natural frequencies according to mode shapes were investigated for three axle driven firefighting heavy duty vehicle chassis. The main purpose of this study is to evaluate the stress condition of the ladder type chassis depending on the natural frequency values and to determine the mode shapes that occur in real road conditions at these values. ORCID NO: 0000-0001-6372-7264
Anahtar Kelimeler: 6x6 Vehicle, ARFF Trucks, FEA, Ladder Chassis Frame, Natural Frequency, Modal Analysis, Vibration
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