Bobbin stresses generated by wire winding
View/ Open
Date
1991-05Author
Metzinger, Kurt
Attaway, Steve
Mello, Frank
Metadata
Show full item recordAbstract
The prediction of bobbin stresses generated by wire winding is now possible by combining a finite element structural code and a rigid body motion code. In this combination of computer codes, the bobbin and the individual wire wraps are considered to be axisymmetric. Each wire wrap is modeled with a single one-node element that has stiffness, mass and radius. The distributed radial load that a wire wrap exerts on the bobbin or other wires is calculated by using a relationship developed for a thin ring with a circular cross section. In this analysis, a layer of wire wraps with a specified tension is applied to a bobbin. The bobbin contracts radially until an equilibrium position is reached. When a second layer is added, the bobbin and each wire in the first layer reach a new equilibrium position. The tensions and the distributed radial loads associated with each displaced wire in the first layer change accordingly. As additional layers are added, the tensions and the distributed radial loads for all the previously applied wires are adjusted to reflect their new positions. The stresses in the bobbin can be determined for any number of wire layers. Bobbin fixturing during winding can be simulated by imposing suitable boundary conditions on the bobbin's finite element mesh. A simple test problem is presented, providing a comparison between the finite element results and a closed-form solution. Quantitative results for bobbin stresses and wire tensions are then presented for more realistic coils. The impact of bobbin fixturing and wire packing structure on the stresses in the bobbin are also discussed.
Citation
Metzinger, K., Attaway, S., & Mello, F. (1991, May). Bobbin stresses generated by wire winding. Paper presented at the First International Conference on Web Handling (IWEB), Stillwater, OK.