Abstract: Mandrels of various configuration, and action, including collapsible mandrels, to be used in forming composite articles with preselected three dimensional shapes and construction are disclosed and described. In one aspect, such a mandrel may have a plurality of discrete segments coupled about a longitudinal axis and collectively forming an enclosure with a substantially continuous exterior working surface. The working surface can have a network of intersecting grooves formed therein, and such grooves can cooperatively establish a substantially continuous interconnected lattice corresponding to the three dimensional geometric configuration to be imparted to a composite article formed. The mandrel may optionally include a removable core assembly to aid in collapse of the mandrel.

Abstract: The present disclosure is drawn to a lattice support structure, comprising a plurality of fiber-based cross supports intersecting one another to form a multi-layered node. The multi-layered node can be consolidated within a rigid mold in the presence of resin, heat, and pressure. In another embodiment, a lattice support structure can comprise a first cross support comprising fiber material; a second cross support comprising a fiber material, said second cross support intersecting the first cross support; and multi-layered nodes located where the first cross support intersects the second cross support. The multi-layered nodes can comprise at least two layers of the first cross support separated by a least one layer of the second cross support. Also, one of the first cross support or the second cross support can be curved from node to node.