Mixed dimensional Finite Element Analysis of Frame Models

Abstract

A technique of idealising frame models using substructures is outlined. All joints are modelled in 3D but, using substructures, each 3D joint is converted to an equivalent stiffness element. The slender regions between the joints are modelled using beam elements. Coupling between the substructures and beam elements is carried out in a manner that conforms with the theory of elasticity. Post-elastic stressing is evaluated using yield loci of the joint substructures. The elastic response of complete frames can therefore be predicted in an accurate and efficient manner. Keywords framed structures, substructuring, yield loci, mixed-dimensional coupling, idealisation Introduction Frames are major structural components in many engineering structures. The design and assessment of such components require consideration in strength, fatigue and fracture. Accurate predictions of static collapse behaviour for aging oil platforms is essential so that reserve strength and likelihood of damage ca...