Datum Mesh 0.2.4

3D frames: frames and trusses in space, drawn on planes and seen in 3D.

3D frames

• Home › 3D Frame: beams that stretch, twist and bend about both axes of their section, and truss bars, anywhere in space. y is up and z is depth.
• Members are drawn on a working plane: Front (x-y), Side (z-y) or Plan (x-z), at a depth you pick or type; members off the plane are shown faint. The status bar reads x, y and z.
• The 3D view shows the whole frame with its supports and loads: turn it with the left button, pan with the right, zoom with the wheel; Front, Top and Iso buttons. Click nodes and members to select them, or to put supports and loads on them.
• Geometry › Repeat copies the selected members (or the whole frame) a step along any direction, with their supports and loads, and joins the copies with beams or truss bars: draw one frame, repeat it into bays.
• The Inspector takes z for nodes, Fz and moments about x, y and z, member loads along z, gravity in z, springs in all six directions, and the roll of a beam's section about its axis.
• Sections give the second moment about the other axis and the torsion constant J (thin-walled formulas for boxes, I and channel sections; your own values for custom sections).

Results in 3D

• Once solved, the members are drawn on their deflected shape and coloured by utilisation, axial force, torque, either bending moment, shear or deflection, with a colour scale. Hover a member to read N, Vy, Vz, T, Mz, My and the deflection.
• The Results page and the printed report have six sums in the equilibrium check, six reactions per support and every member's forces; the report draws the frame isometric.

Trust

• Help › Verification: 69 checks, all passing. New: a 3D cantilever bending each way, twisting and with its section rolled, under point and member loads; one along z; an L-shaped cantilever bent in plan, where bending and twisting add up; a tripod of truss bars; and the portal frame solved in 3D, giving the plane solver's answers to 1 part in 10¹³.
• Random 3D frames (150 of them) solve with their reactions balancing the loads, or say why they cannot.

Not yet in 3D: natural frequencies and buckling (plane frames have both).