Determination of the belt force before the gross slip

• Belt force in the contact region before the state of impending slip is determined.
• Pressure and friction forces are evaluated at an arbitrary stage of slip growth.
• Total pressure and friction forces are not proportional or orthogonal to each other.

The mechanics of belt friction before the state of gross slip is considered. The variation of the belt force within the contact region is evaluated based on the assumption of gradual growth of slip from the pull-end to the hold-end of the belt, as the pull force increases towards its Euler's value. The local pressure and friction forces exerted by the belt on the cylinder are also determined. Both flat and V-shaped belts are considered. The total pressure and friction forces are evaluated at an arbitrary stage of slip growth. They are neither proportional nor orthogonal to each other, unless the state of gross slip is reached throughout the contact range.