Influence Surface Analysis is used to conduct the live load analysis in the 3D FEM analysis. Unit loads are applied at each deck node in the stage 3 FE model to generate influence surfaces for shear, moment, reaction, rotation, and deflection effects. The influence surfaces are then loaded for truck, lane, truck pair or tandem pair analyses to find the maximum effects.
The 3D-FEM transverse loader will automatically load the travelway based on user input. Because the influence surface analysis is used for 3D FEM live load analysis, live load distribution factors are not calculated or used.