NAFEMS Benchmark Challenge 5 - The Solution

In the final year of his engineering degree course a student was introduced to finite element analysis and conducted an assessment of a simple, planar, pin-jointed truss structure. This included a modal analysis to establish the natural frequencies of the structure. Being a cautious student he thought he had better conduct some verification tests on the axial element used to model the truss structure. He found an analytical solution for a bar, fixed at one end and with uniform cross section and material properties. He conducted a convergence study on this test structure in two commercial finite element systems (CS1 and CS2) starting with a single element and then performing uniform mesh refinement until he reached a mesh with 16 elements.