Design, development and testing of a 2-DOF articulated dump truck suspension seat
This project entails the design and development of a new 2-DOF articulated dump truck (ADT) suspension seat. A study of the ADT vibration environment was conducted using data measured with accelerometers inside the cabin. With the system’s required operational capabilities determined, the concept design phase resulted in a feasible concept. The first prototype was manufactured based on the initial set of specifications. A variety of numerical modelling techniques were used to analyse and evaluate the seat’s dynamic response. Vertical and lateral laboratory tests of the suspension seat with human occupants were completed. The vertical lumped parameter model of the suspension seat with a human occupant gave good correlation with the laboratory measured frequency response. A broad band input signal, and not the ISO 7096 (2000) EM1 signal, was used to obtain the frequency response used to verify the lumped parameter model. The SEAT values for the ISO 7096 (2000) EM1 signal and various ADT road conditions were calculated using the lumped parameter models for a small, medium and large subject, the same three subjects used in the laboratory tests. SEAT values using the ISO 7096 (2000) EM1 signal of 0.94, 0.93 and 0.88 were obtained for the small, medium and large subjects. The lowest SEAT values obtained using the road data were 0.63, 0.56 and 0.48 for the small, medium and large subjects. The transmissibility curves determined from the lateral laboratory tests were used to calculate the SEAT values for the lateral ADT cabin vibrations. The lowest SEAT values obtained were 0.83, 0.83 and 0.82 obtained for the small, medium and large subjects. After all the results from the testing and modelling were evaluated the design was assessed. All the data and information collected was used as input for the design of a second prototype, which was not manufactured. Not all the set specifications were achieved for the first prototype, but the new suspension seat gave comparable vertical vibration isolation performance to that of expensive commercially available ADT suspension seats. The lateral suspension demonstrated good lateral vibration isolation and is a feature not currently available in current ADT suspension seats.