Optimum finite element for the 1-D geometrical structures

Abstract

Generally, in finite element method (CAE software like ANSYS) to solve the bar and truss problems two-node link element will be used. In 3-D link element, each node contains three DOF (Translations in x,y,z directions). To solve the beam structures, two-node beam element that has 6 DOF (3 Translations + 3 Rotations) will be used. In both theory and finite element CAE packages, it is creating slight confusion and trouble to use different elements for different structures as stated above. In the present work, an attempt was made to solve the bar and truss problems with beam element, as beam element already contains the DOF of link element. Finite element method simulation software was used to perform the analysis. Link 180 and beam 188 elements were used from the ANSYS library. The possibility of using the beam element for both bar and truss problems was verified for three different structures viz. stepped bar, plane truss and space truss in both static structural and modal analysis cases. From the results, it was observed that link element can be replaced with beam element conveniently for static structural and modal analysis cases with few assumptions.