Abstract: Uneven distribution of the residual stress is the main element to cause the deformation of a workpiece. Toreflect the relationship between clamps and residual stress, finite element models with different clamping schemeswere built and the clamping process was simulated. It is verified that clamping points have great effect on the residual stress, but that of the clamping order is little. In addition, workpiece distortion introduced by the residual stressis analyzed and compared under different clamping conditions. Finally, a conclusion is obtained : To reduce theworkpiece deformation due to the residual stress, it is advisable to adopt even distributed clamps without regard tothe clamping sequence.

Key words: clamp, residual stress, optimal machining, deformation