DANotes: Finite elements: Frontispiece

Finite elements - frontispiece

Freehand isometric sketch of the airways in a typical mine ventilation circuit powered by the induced draft fan on the surface at top left. Each airway is essentially a flow resistance element, the resistance being a function of length, cross-sectional size, wall roughness etc. The airway junctions ( nodes ) are numbered sequentially in the sketch. The system is thus a 1-net, ie. a network of line elements, each line connected between two nodes.
Preliminary network model for the quality of rangeland in the Sahara. The sketch only goes so far as to identify the causes and effects between related factors in this study in the field of Agricultural Economics.
A FEM1 mesh of triangular in-plane elements for evaluating stress concentration around the central hole of a uniformly loaded square plate. Only one quarter of the symmetric prototype is modeled thus conserving memory without sacrificing accuracy ( or increasing the accuracy possible with limited memory ). The model supports are chosen to minimise constraints thus mimicing the prototype and preventing rigid body motion.
An assemblage of three-dimensional brick elements models a representative slice of a concrete reactor vessel. The idealised model of the slice appears on the left; the corresponding finite element assembly on the right. Supports are not shown.
Determining the stress intensitiy at a corner crack is aided by preferential mesh refinement. The sketch shows the mesh both before and after deformation.
Longitudinal symmetry permits this assembly of flexural plate elements to model a 150 tonne ore trailer. The elements are two-dimensional, either triangular or quadrilateral - and unlike the elements of FEM1 above, support both in- and out-of- plane loading.