Insufficient supports will allow rigid body motion. Effect of wrong support types: (The stiffness matrix will be singular.) Each of these will result in different displacements,strains and stresses. Mistakes that may go unnoticed: -Wrong element type(e.g.axisymmetric instead of plane element) Supports wrong in location,type or direction Loads wrong in location,type,direction or magnitude Other data (e.g.units) -An element defined twice -Physically meaningless connections(e.g.axisymmetric element to plane element) • Insufficient supports will allow rigid body motion. (The stiffness matrix will be singular.) • Mistakes that may go unnoticed: –Wrong element type (e.g. axisymmetric instead of plane element) – Supports wrong in location, type or direction – Loads wrong in location, type, direction or magnitude – Other data (e.g. units) – An element defined twice – Physically meaningless connections (e.g. axisymmetric element to plane element)