Live Loads [FEA]

Live Loads holds the objects used for influence-surface traffic loading.

Vehicles define axle configurations. Design Lanes define a traffic lane - its width, the vehicles that travel in it, the accompanying lane load, and the rules for placing vehicles within it. Influence Surfaces & Lines define the loaded region and the grid of unit-load positions used to build the influence coefficients. Live Load Cases tie the lanes and surfaces together and run the search.

The analysis places a unit load at every grid point, solves, and then searches for the vehicle and lane arrangement that maximizes each response. Results are therefore envelopes: each value is the worst case over all positions, and different values correspond to different truck positions. They are not a single equilibrium state, and pairing two enveloped maxima for an interaction check combines actions that never coexist.

Grid spacing is the main trade-off: finer grids find sharper peaks, at a cost that grows quadratically.