Grillage analysis suffers from the following shortcomings based on E.
Hambly: (i) For coarse mesh, torques may not be identical in orthogonal directions.
Similarly, twists may differ in orthogonal directions.
(ii) Moment in any beams is mainly proportional to its curvature only.
However, moment in an element depends on the curvatures in the beam?s direction and its orthogonal direction.