In the given simulation video one can see ripple formation or bellow manufacturing process. In this process the tube is compressed axially and bulge is produced at several equidistant locations. Finally the bulged tube is compressed axially to collapse the bulged regions and finally bellows are formed. In the left hand side of the video one can see the full in section of tube and die assembly. Upper and lower die are used to press the tube. Upper and lower supports are used to hold the tube ends. The central support is used to create a bulge in the tube under axial compression. The material of the tube is mild steel. The hydraulic presses are used to compress the tube. Right hand top side of the video shows the outer surface of the assembly. While the lower right hand side of the video shows the various stages of the tube from initial stage to intermediate stage and finally the bellow tube.