Development of a Cab Suspension for a 4 x 2 Semi-truck

In this paper, within the scope of a competitive product development process in accordance with customer demands and ISO comfort standards, development of the cab suspension system for a 4 x 2 semi-truck is presented. In the first part of the study, benchmark vehicles were selected due to the customer demands. Cab comfort evaluation tests were applied to these vehicles. By this way proper ranges of the design targets were determined. Subsequently a first level (or mule) prototype of the vehicle was produced. The acceleration and displacement data are collected from the cab and the chassis of the first level prototype. By using nCode Glyphworks commercial software, these data were refined to create the input functions for the Adams/Car (TM)-based multibody dynamics (MBD) cab suspension model. Virtual acceleration and displacement data were also collected via the MBD model and correlated with the data obtained from the first level prototype. After the model verification, a design of experiments (DOE)-based optimization study was performed via Adams (R)/Insight commercial software to achieve required characteristic curves which satisfy design targets. With the use of new suspension system features, second level prototype was also produced and validation tests are performed. After verification of suspension characteristic, dynamic response of the cab was evaluated with respect to ISO 2361 comfort criteria. By using the absorbed suspension energy method, comfortable working durations for driver were determined according to ISO 8608 road profiles.