Archie

grabcad

This is Archie. Archie is an inflatable gantry system that can provide significant lifting capacity combined with mobility and stability. The main feature is the four-legged support arches, which each are formed from eight 290 mm diameter tubes. The total amount of Vectran fabric is close to 230 m2. Lifting is done with a four-point cable system, which improves working area size and prevents gantry from tipping over. Each leg can be separately moved and contain their own power and pressure system with control and communication electronics. When pressurized, the system can produce 8000 to 15000 Newtons of lifting force, depending on the internal pressure and from the final accessory load on the frame, which includes solar panels, micro-meteoroid protection, and deployment system. Total weight of the system is around 1800-2000 kg, depending on the configuration. PDF drawing included.Finite element simulations were done with membrane elements, which do not carry bending moment loads. This makes them an ideal tool for estimating the structural stresses and stability of the inflatable structure as the load-carrying capability is related more to the shape and internal pressure than to the material. Non-linear mechanical simulations were made with a quarter model, and reaction forces from a fixed tubing crossing were extracted from the result to estimate lifting capacity with various pressures. Future work would include optimizing the arch shape to improve the weight-stiffness ratio to specific requirements. Adjusting FE-parameters to better correspond to fabric testing data for membrane elements. Testing solar panel deployment mechanisms and inflation parameters such as initial inflation shape and final load-carrying capability. Used software: Onshape (CAD), Salome-Meca/code_aster (FEM), Blender (Renders). The model of the astronaut is used under CC BY 4.0 license by author fasteng (https://sketchfab.com/fasteng). Design evolution and deployment animations can be viewed from the version history folder.