In example “RUBY/EX34/checkInertiaLoads.rb”, complex Grid Point Forces are manipulated. Several functions are defined in the example:
“printFM” function prints the complex global FM array to the specified output.
“calcOneGlobFM” calculates complex global forces and moments for one specified loadcase and subcase and several types of Grid Point Forces outputs (Inertia forces, Internal Forces...). The calculation is done for one Group of elements and nodes corresponding to a part of the structure, and for one Group of nodes defining an interface.
“check” outputs several results extracted on GRID 70013. (This method is used to check Grid Point Forces equilibrium on a node.)
The method listed “calcOneGlobFM” is used to check the global forces and moments on upper sandwich panel. Grid Point Forces are extracted on the Group of nodes and elements corresponding to Group “pan_SUP”. Another extraction is done on the 9 nodes at interface to the three fittings supporting this sandwich panel.
The extraction has been done for different versions of the SOL111 analysis. The three versions differ by the modal basis that has been considered in the calculation. Results indicate that the number of modes considered matters. There is a significantly better match of Global MPC and Inertia loads when a large basis of eigenmodes is considered in the analysis.