Static and dynamic study of the industrial vehicle transmission adopting composite materials

The present research concerns the study of the lightening of the transmission of a commercial vehicle and in particular a truck with a power of 235 kW by using composite materials. The study was first approached numerically by defining an in-depth model with lumped parameters that encompassed all the elements of the transmission with their respective performances, then numerical analyses were conducted to confirm the results obtained analytically. The dimensions of the driveshafts in the transmission were chosen considering three variables, which affect the static and dynamic behavior of the transmission. These are the stiffness, the static and fatigue safety coefficient, the eigenfrequencies and the torsional buckling load to obtain a component, designed with the new materials with the same performance as that made of steel. The results show that using transmission shafts made of composite materials (particularly carbon fibers) results in a final weight savings of up to 30 % compared to the identical components made of steel with equal static and dynamic performance.