Laserfiche WebLink
C. METHOD OF ANALYSIS <br />An analysis of the roof top structure was performed using STAAD (Structural <br />Analysis and Design)/Pro, a three-dimensional Finite Element computer program <br />developed by Research Engineers, Inc., Marlton, New Jersey. <br />STAAD/Pro is capable of performing Static Stiffness, Static P-Delta, Eigenproblem <br />and Response Spectra Analyses on structures modeled with assemblages of frame <br />and plate/shell elements. Deflection, support reaction and member force results <br />can be obtained at any point in the structure for member and joint loadings as well <br />as boundary displacements. <br />A capability offered by STAAD/Pro to be utilized in this analysis is the ability to <br />combine load cases to determine the critical loading combination for a structure. <br />This feature will allow us to combine gravity and wind loads to determine the <br />maximum results in the roof top structure. <br />Structural Model <br />The roof top structure'is modeled with individual beam members representing each <br />truss and ladder, section. For convenience in reporting results, a node is located at <br />each intersection of the component intersection. An isometric view of the FEM <br />model for the 65 ft. x 45 ft. roof top stru,cture with sound wings is shown inFigure 4,·and the joint and member numbering-Acheme is shown in Appendix B. <br />The stiffness of each member component is modeled by inputting the appropriate <br />section properties of each truss and ladder section determined in Appendix A. In <br />addition, the member end results will be compared with the structural capacities as <br />determined in Appendix A. <br />Design Loadings <br />The Roof Top structure model was analyzed for the design loadings outlinedbelow: <br />Primary Load Case 1: Gravity Loads - Self Weight (SW) <br />The self weight of the roof top structure is applied as uniformly distributed loads <br />to the apex members. The total weight of the 65 ft. x 45 ft. roof top structurewith sound wings, applied in our analysis, is on the order of 8,500 lbs. <br />----- <br />--I--I11 <br />- <br />1. <br />6 <br />-- <br />----.0 -