Abstract: The nonlocal friction law proposed by Oden et al. was adopted in order to consider the nonlocal friction effect of the asperities on the rough contact surface between the die and the workpiece in several kinds of metal plastic forming problems.The mechanical equilibrium equations with the integral-differential form were obtained by using the engineering method or slab method, and solved approximately by using the perturbation method. The normal stress distributions on the contact surfaces in metal forming problems with nonlocal friction were obtained, and the factors which affect the nonlocal friction effect were analyzed.

Key words: nonlocal friction, plastic working, approximate solution