Reconfigurable Structural Joint
- Thursday, 01 May 2014
Commercial uses include home devices such as exercise machines that need strong structural support, but require low-volume storage.
Marshall Space Flight Center, Alabama
This technique allows for rapid joining of reconfigurable structures. Currently, permanent structural joints are made in factory settings or in situ. However, reconfigurable structures require appropriate structural joints that must be made in situ, and must join/disjoin without inflicting any damage on the structure or the joint. The joining/disjoining operation must be rapid and repeatable without damaging the structure.
Both in situ and factory joints that have a capability to provide full structural support are not trivial to engage or disengage, and require significant time and effort to complete the joint. Nonstructural in situ joints or joints that have a capability to provide some structural support can be mated and, in some cases, unmated without a significant time and effort. Development of in situ joints that can be repeatedly engaged and disengaged provides the ability to form various robust structures in situ, which in turn lowers their initial volume and enhances their versatility.
This invention allows rapid in situ structural joining of adjacent panels in order to utilize structures more efficiently and with higher versatility. The invention achieves this by providing a universal bar between adjacent panels that houses receivers for the Acme screws. Acme screws are placed on panels and are engaged using a spring system. The Acme screws generate the necessary preload between the panel and the universal bar so that joint separation does not occur during panel loading. The load is then transferred between the panels through the Acme screws and the universal bar. The Acme screw-generated preload is self-equilibrated with the universal bar, and does not produce additional stresses on the panels.
The reconfigurable joint can be used to join a wide variety of different panel architectures composed of various materials. The joint can serve a structural purpose, but it can also be used to assemble panels that do not require significant load transfer. It allows for a correct load transfer and post-tensioning application as well as a rapid joint engagement between panels. The joint is able to transfer the appropriate panel loading and be used on reconfigurable structures.
The invention encompasses existing technologies to achieve a novel approach to join reconfigurable panels rapidly. This approach can be used for a wide variety of materials including metallic and composite. It is especially useful for reconfigurable structures where a rapid mechanical joint is needed. The joint does not rely on friction as all forces and moments are transferred by mechanical means, either through the bearing surfaces of the joint assembly or through the Acme screw, which applies the post-tension.