Design

The original design was a cross-shaped plate which bolted onto each of the structural C-channels. It had axially-oriented cutouts which would allow the parachute lines the be attached, and would no have any edges that were rounded or not right angles post-waterjet. Due to its thickness, my primary concern was the mass of the component. My next biggest concern was the huge reaction force on the face adjacent to the inside of the C-channels caused by the moment from the parachute. Finally, I was concerned that the current orientation of the cutouts would inhibit the parachute lines from freely rotating, and that the lines would be held in tension against a sharp edge. The first change I made was angling the face adjacent to the inside of the C-channels such that and rotation upward would not cause interference between the mounting plate and C-channel. Next, I rotated he cutouts to be oriented circumferentially and added fillets to the edges such that the parachute lines could rotate freely, eliminating the stress concentration caused by the sharp edge.

Analysis

The primary analysis done on the mounting plate was a static simulation. Like the nose cone ring, I added the structural C-channels as fixed, rigid bodies, and interfaced them with the mounting plate using pin connectors. I applied an upwards load on the mounting plate on the bottom face of each of the parachute mounting points. This was not the most accurate representation of the actual parachute load, which would be distributed over an area and at an angle; however, the perpendicular load case represents a more conservative estimate for the moments present in the component, which was of greatest interest. I iterated through analysis and redesign while decreasing geometries in the highest-FoS areas in order to minimize mass while maintaining a minimum FoS of 1.5.