Free Web Tool

Bolt Group — Eccentric Loading

Elastic vector method for in-plane eccentric loading on a bolt group — direct & torsional shear components, controlling bolt and design check.

Inputs

kN
deg from +X axis
mm (point of load from origin)
mm
kN
mm. Origin can be anywhere; tool computes centroid automatically.
Method
  • Bolt centroid (x̄, ȳ) computed automatically; eccentricity referred to centroid.
  • Direct shear per bolt: rd = P / n.
  • Torsional moment M = P · eperp resolved into x and y.
  • Torsional shear: rtx = M·y/J, rty = M·x/J, where J = Σ(x² + y²) about centroid.
  • Resultant per bolt = √[(rdx+rtx)² + (rdy+rty)²].
  • Method does not include bolt slip / friction. Use AISC Manual Tables for instantaneous-center solution if needed.

Results

n bolts
Centroid (x̄, ȳ)
Polar Moment J
Direct Shear rd
Eff. Eccentricity e
Max Bolt Force
Demand / Capacity
StatusOK
#xyrxry|r| kN