Figure 1
The figure contains four images arranged in a two-by-two grid, each showing a different wheel-related design. Image “(a) Elastic wheel” is a rendered cutaway diagram of a circular wheel or hub with several concentric layers, including an inner core, a surrounding elastic-looking ring, and an outer metallic rim. Image “(b) Noise reduction wheel” is a top view photograph of a shiny circular metal wheel or disc with a solid central hub and several evenly spaced small components or segments around the rim; a measuring or suspension device hangs vertically across the center. Image “(c) Damping ring wheel” is a close-up photograph of a metal rim, where a person’s hand holds a thin tool or wire near a groove that appears to contain a filler material. Image “(d) Constrained damping wheel” is a photograph of a large circular metal wheel with a recessed center, lying horizontally while a person holds a long flexible element, such as a cord or wire, across its diameter.Common structural forms of damping wheels. (a) Source: http://mms2.baidu.com/it/u=2784804803,2668463334&fm=253&app=138&f=JPEG?w=321&h=230, (b) Source: Wheel with absorber, (Photo H. Neumann, IFS, RWTH Aachen), (c) Source: Authors’ own work