Geodesic dome structural analysis and design

Geodesic dome is one of the simplest forms of structure which has a very unique spherical or partial-spherical shape. The skeleton of the structure consists a number of unequal and straight structural members to form its many stable triangular elements in order to provide resistance to the gravitational, wind and seismic loads. The geodesic dome has the capacity to achieve large span without any form of internal posts, load bearing walls or deep beams or trusses, the load is evenly distributed through the surface of the dome. On the other side, a conventional building would require more material and space to achieve larger span, and deflection control and bracing requirement may become a challenge for the conventional form. Whereas, the geodesic is very effective in limiting deflection, and it is self-braced through its stable triangulated elements. Geodesic domes can be constructed from various materials, (e.g. timber, steel) and a very light PVC cover is applied to the outside of the main structure to shield the dome from weathering. It provides a strength-to-weight ratio that many others could not compete. The fast speed of erection, competitiveness in material costs and its resilience to natural disasters have made dome construction applicable to many agricultural, commercial applications. The purpose of this report is to present the background information about geodesic dome, also to verify a designing methodology and to develop design procedure based on the most critical loading, that is wind load for this type of structure. The aid of computational analysis has been considered as the key tool to obtain design data from the complex 3D dome model, and then manually checked against steel structure standards AS 4100-1998. In addition, an Excel spreadsheet was developed using finite element analysis method to extract the forces for each element, then the results were compared against the outcomes from computational analysis method for validation purpose. The spreadsheet was aimed to standardize the design procedure and to reduce the time required for analysis and design in the future, and sensitivity analysis could also be conducted easily and quickly using the spreadsheet