Datum Mesh 0.3.0

3D solids: a part's outline extruded by its thickness and solved in 3D.

3D solids

• Home › 3D Solid: draw the outline and holes in Section, exactly as for a plane part, and set the thickness; the part is extruded along z and shown in the 3D view.
• Supports and loads go on faces: an edge in Section stands for its side face, and the back and front faces have their own buttons while a support or load is being placed. Fixed, roller and symmetry supports; pressures, face forces (now with Fz too) and gravity.
• The section's mesh is swept through the thickness in layers of wedges: 18-node wedges from the quadratic mesh (accurate), 6-node from the linear one. Layers are automatic, or set in the Inspector.
• Once solved, the surface is coloured by any of 14 results (von Mises, σ1, σ3, each stress and shear, the displacements, the safety factor) on the deformed shape; hover to read a value. The Results page and report give the largest and smallest values anywhere inside, with where, the reactions and the equilibrium check in six sums.
• New examples: the L-bracket as a 3D solid, and a blank 3D solid.

Quicker solves

• The sparse solver now uses every core of the computer, and big 3D models store half the matrix: about 90 000 unknowns of a 3D solid solve in about 6 s and 1.2 GB on four cores.
• A 3D solid is limited to 200 000 unknowns, with a message saying how to make the mesh coarser, so a too-fine mesh cannot run the computer out of memory.

Trust

• Help › Verification: 85 checks, all passing. New: a 3D patch test (a uniform stress reproduced to 1 part in 10¹⁴, with the thinning), a 3D cantilever against Timoshenko beam theory (0.005 %) and its bending stress, and a thick cylinder in 3D against Lamé (hoop stress 0.5 %, bore movement 0.003 %).
• Random 3D solids (40 of them) solve with their reactions balancing the loads in all six sums, or say why they cannot.