Abstract: A collapsible, coiled mandrel, for use in co-curing of a hollow carbon-epoxy structure such as a stringer in aircraft construction, is made of a coil having an outer coil shape resistant to external compression forces when used as a mandrel during lay-up and curing, and is collapsible when an end of the coil is pulled along its longitudinal axis so that it can be easily removed after curing and discarded.

Abstract: A collapsible, coiled mandrel, for use in co-curing of a hollow carbon-epoxy structure such as a stringer in aircraft construction, is made of a coil having an outer coil shape resistant to external compression forces when used as a mandrel during lay-up and curing, and is collapsible when an end of the coil is pulled along its longitudinal axis so that it can be easily removed after curing and discarded.

Abstract: A collapsible, coiled mandrel, for use in co-curing of a hollow carbon-epoxy structure such as a stringer in aircraft construction, is made of a fiber stiffened with doping material that maintains an outer coil shape resistant to external compression forces when used as a mandrel during lay-up and curing, and is collapsible when an end of the fiber is pulled along its longitudinal axis so that it can be easily removed after curing and discarded. A method of fabricating a collapsible, coiled mandrel employs a mold with a shaped recess for forming a coil with a fiber wetted with a doping material fed in by an applicator, and rotating the applicator while backing it out to form the coil in the mold. In an alternative embodiment, a collapsible, coiled mandrel may be formed of a metal coil having a mandrel-shaped cross section and sleeved in a protective liner.

Abstract: A collapsible, coiled mandrel, for use in co-curing of a hollow carbon-epoxy structure such as a stringer in aircraft construction, is made of a fiber stiffened with doping material that maintains an outer coil shape resistant to external compression forces when used as a mandrel during lay-up and curing, and is collapsible when an end of the fiber is pulled along its longitudinal axis so that it can be easily removed after curing and discarded. A method of fabricating a collapsible, coiled mandrel employs a mold with a shaped recess for forming a coil with a fiber wetted with a doping material fed in by an applicator, and rotating the applicator while backing it out to form the coil in the mold. In an alternative embodiment, a collapsible, coiled mandrel may be formed of a metal coil having a mandrel-shaped cross section and sleeved in a protective liner.

Abstract: A computer-based method for generating multi-generational relationships within a relational model. The method includes applying, with a processing device, a filter to parent node data and child node data in the relational model, the relational model stored in a computer memory, adding filtered data to a database within a computer memory via instructions executed by the processing device, the filtered data including relational model data that passed through the filter, and applying, through instructions executed by the processing device, a parent node selection process to every child node in the filtered data that is associated with a parent node record not conforming to the filter.