BoltCalc 3D — fastener group force distribution

Fastener layoutpositions in mm, plate X–Y plane, Z normal

Rows

Cols

dx (mm)

dy (mm)

Start ID

Generates a regular bolt/nail/screw array from the first empty row. Build any pattern by stacking several grids or editing rows directly.

ID	Xmm	Ymm	Shearin-plane	Axialout-of-plane

Case	NkN, +T	VxkN	VykN	MxkNmm	MykNmm	MzkNmm	exmm	eymm	Note

N is axial (normal to the plate, +tension). Vx, Vy are in-plane shears. Mx / My bend the connection about the in-plane axes; Mz is in-plane torsion. ex, ey offset the force resultant from the group centroid — the app reduces them to centroid moments automatically. Rows sharing a Case name are summed.

Axial (out-of-plane) behaviour

Two-way — tension & compressionEvery fastener resists axial load both ways; the neutral axis sits at the group centroid. Suits bolted splices with cover plates, or a quick elastic check. This is biaxial bending of the fastener group. Tension-only + bearing flangeFasteners take tension only; compression is reacted at a nominated flange line (rotation about the flange). This is the correct model for moment end-plates, baseplates and hold-downs — bolts can't push.

Bending axis

Compression flange y = mm

Centre of compression is taken at this line; fasteners on the tension side carry force proportional to their lever arm from it. If the bearing reaction comes out negative the section is in net tension there and a different model is needed — the diagnostics will flag it.

Scope

BoltCalc returns the statics force on each fastener — the share of the applied actions it transmits, split into axial tension/compression and resultant shear. It is a force engine, not a capacity check: it does not apply BS 5950 / EN 1993 / EN 1995 resistances, prying, slip or timber group effects. Use the per-fastener forces as the demand side of your own checks.

Title

Description

Coordinates are in the fastener plane (mm), z = 0. The same engine handles a gangnail/nail plate (many fasteners in shear), a bracket (shear + torsion), or a moment end-plate (tension + bearing). Fastener type doesn't change the distribution — only its capacity, which is out of scope here.

Run the analysis to see per-fastener forces.

Run the analysis to see the summary.

Run the analysis to see diagnostics.

Axial T/C Shear vectors Values IDs Grid

Zoom