A client that manufactures and supplies products to defence industries presented CSGtech with an Epoxy Glass Fabric bush that was delaminating in service.
Understanding the Issue:
The current part was machined from a moulded epoxy cylinder with a spiral-rolled glass laminate reinforcements. Small billets were cut from the cylinder and machined into the bush shape. When machined, the reinforcing was linearly aligned to the centre axis, which facilitated the delamination/shearing of the bush under transverse loading.
Being a defence application that had been in place for many years, the type of material and supplier could not be varied. Working closely with Tufnol Composites UK, we were able to custom manufacture thick epoxy sheets with laminated reinforcing that would be cut into squares blocks for machining. The laminate sheets were layered in transverse direction to the loading axis.
With the lamination perpendicular to the axis of the applied forces, the bush could withstand the compressive load without delamination. The new configuration greatly increased the service life of the product.