GrillageCalc: Online Grillage and Deck Analysis

Use this tab for the model title and project notes saved with the data file.

The five PDF fields are placed in the calculation-sheet title block. Their positions and the printable content area can be adjusted in the Report tab.

Enter grillage node coordinates in the global X-Z plane. Block generation: for a numeric node row, fill No. of Inc, Node Inc, X-inc and Z-inc to generate a series automatically. If End / Inc is Y, then X-inc and Z-inc are treated as end coordinates. To remove a generated sequence, enter its first Node, No. of Inc and Node Inc, then type Delete in End / Inc. For a copied block, enter B1 to copy the nodes generated by numeric row 1, or enter B1-2 to copy an explicit node set.

Enter member node chains such as 1-2-3. Section refs link to the Section Props tab. 1-2-3 creates members 1-2 and 2-3. Shorthand 1-2--6 expands automatically to 1-2-3-4-5-6 using the increment implied by the first two node numbers. Member generation: enter No. of extra and Node increment to copy the whole chain.

For example 1-2-3-4 with No. of extra = 4 and Node increment = 5 also creates 6-7-8-9, 11-12-13-14, 16-17-18-19 and 21-22-23-24.

Use Fixity Yxz for vertical-Y translation and rotations about global X/Z. Uppercase Y restrains vertical translation; lowercase x and z restrain rotation. Enter numerical elastic stiffnesses in Trans-Y, Rotation-x and Rotation-z. Gap-Y + is bearing/downforce-only (no uplift); Gap-Y - is hold-down/uplift-only. Support generation copies the row using No. extra and Node increment.

Enter nodal loads, member UDLs, member point loads, and combinations. Every populated load row requires an explicit case name. Global-Y loads are negative downward. Positive moments follow the right-hand rule about global X and Z. Nodal-load generation copies the case and actions using No. of extra and Node inc. A chain such as 1-2-3 applies the same vertical UDL to members 1-2 and 2-3. Point-load distance a is measured from the start node of each member in the chain. Use repeated combination names on adjacent rows. ULS factors apply to member forces and reactions; SLS factors apply to displacements. Six blank definition rows are kept visible automatically.

Generation example: node 101 with 4 extra and increment 10 loads nodes 101, 111, 121, 131 and 141.

For grillage, Izz is the vertical-Y bending inertia and J is the torsion constant. A nonzero area and unit weight automatically generate SWT. Engineering notation such as 200E3 and 120E6 is accepted. Select a target row before opening the Section Props Helper if you want the helper result inserted into that row.

Displacement results from the last analysis. Click a node row to highlight it and the matching node in the view; click again or press Esc to clear the selection.

Member end forces from the last analysis. Click a table row or a canvas member to isolate its active force diagram. Click or drag along its member span or force diagram to position the in-member force cursor. Double-click the cursor or press Esc to remove it; click the selected row again, press Esc, or click empty canvas to show all members.

Support reactions for the selected load case or combination. Click a reaction row to highlight the support/node in the view; click again or press Esc to clear the selection.

Envelope table of maximum member end forces across all solved load cases and combinations. Click a member row to highlight it in the view.

Build the printable A4 PDF output pack from selected input tables and session captures. Use Capture below the canvas for views, or Capture at the top right of result tables for selected table rows. Captures are kept only for the current app session and are not saved in the data file. Use Edit sheet layout if the PDF title-block/background needs adjusting.