Research on contact and friction in three-dimension model of multi-stranded wire helical spring

Based on the forming and loading principles of multi-stranded wire helical spring,the article firstly pays more attention to the state distributing of the contact facet. With the help of predecessors' work, the novel model then divides the facet into three zones, which including spacing zone, spring zone and friction zone. On further more research, it analyses the boundary and contact judgment quantitative conditions under the coordination of the Normal-P_tangent-Tangent , respectively.