Model of dynamic behavior for frame mounted truck components

Abstract: In the truck industry, it is crustal to test components against fatigue to make sure that the trucks stand up to the high demands on durability. Today’s testing methods have some disadvantages; it is quite a time-consuming process, but more important, similar tested components cannot easily be compared due to the load spread the components are subjected to. It is therefore desirable to test the components in a standardized way. One way to do this is to use a synthetic signal which is a large number of unique truck measurements combined. The synthetic signal only contains information of the frame’s vibration and not any components. The purpose of this project was to create a model that uses the synthetic signal to describe the motion of components.   Two approaches were used, the first was to base the model on previous measurements, the second one was to base the model on analytical equations. These models were experimentally tested in a 4 channel shake rig, and a silencer was the component chosen to be tested. For the model based on measurements, the load was shown to have a large spread which was hard to control due to the spread in the measurements. The second model was easier to control where the damping factor can be chosen and varied. A promising model was the analytical model using 10% damping applied to the synthetic signal, it covers most measurements without overestimate the load of the component. However, the model was only developed for the silencer acceleration in the z-direction, and it is recommended to develop it for the x-direction as well. The method used in this project could also be used to develop models for other components.