Challenge:
Our client supplied us a design for an aluminum truss LED wall. The assembly was used for the 2009 Academy Awards outside of the Kodak Theater. Hopper Engineering was asked to provide a strength analysis and an overturning check of the structure to ensure the safety of the patrons.
Resolution:
A strength analysis of the structure was accomplished using RISA-3D, and applying the truss self-weight, wind loading, seismic loading and the weight of the LED screen. The resulting forces in the truss members were checked against the acceptance standards for a 20 1/2″ box truss. The box truss end plate connections were analyzed using ANSYS. The structure as a whole was checked for overturning (Two overturning scenarios were checked: overturning due to a wind load of 30 mph max, and overturning due to a 0.1g max temporary seismic event). The wind load was calculated using the latest edition of the California Building Code, or CBC-07, which referenced the ASCE7-05, Chapter 6 for wind load calculations.
