Ok so for a project of mine I need to calc. the force required to steer an articulated heavy on road vehicle and to overcome friction (so I need to calc frictional forces too). I understand I need to draw FBDs but it has been a while since i have done that and I have never worked with an articulated vehicle and it is very confusing for me. I have been told that this can be worked by using only one side (left or right) of the vehicle as it is a dual-cylinder setup and calculating moment about center pivot. Is this moment the turning force? Actually, on second thought it would not be as it is a torque but how do I use that to get the turning force? So what I know: - vehicle's front axle and rear axle weights (both are single-axle but with 4 tyres front and rear) -I know the hydraulic working pressure and area of the pistons and hence I have calculated the force required to extend and retract the cylinders (so the max. force that can be provided through the hydraulics to steer the vehicle) -max articulation angle either side of center line (unsure if important to know) -angle and length from center pivot to front cyl mount -length mount to mount of cylinder -length at 90 degrees from center pivot to cylinder -length from center pivot to rear cyl mount -offset angle as to which cylinder is mounted from the 90 degree position when steering is centered (value is 0.31 rad to the left of 90 degrees when looking at right hand side..so cylinders point inwards at front) What do I do now, how do I go about calulting the turning force and the friction? Any help would be appreciated sorry for the length of this..