MP-28 · JOINTS AND FASTENERS
Eccentric Bolt Group
Screen a circular bolt group for direct shear and elastic moment load per governing bolt from bolt count, group radius, direct load, and moment.
Preliminary design support. Your inputs and results stay in this browser.
WHAT THIS SCREEN ANSWERS
Bolt groups often see both a direct load and a moment that increases demand on some fasteners more than others. Equal sharing is only correct for a centered direct load. This screen gives an early circular-group estimate that separates direct shear from the additional elastic demand caused by an entered moment.
Enter bolt count, bolt-group radius, direct shear load, and moment. MechPlane divides direct load equally, then calculates a maximum moment-induced bolt load using a simplified circular pattern. A centered direct load with zero moment gives equal direct sharing, which is the intended basic fixture for the model.
Real bolt groups are governed by geometry and joint behavior. Bolt positions may be irregular. Loads may be eccentric in two directions. Preload, friction, prying, bearing, plate stiffness, clearance, holes, welds, slip, yielding, and fatigue can shift the load path. The model is intentionally a screen, not a detailed connection analysis.
Use the output to spot whether a moment materially changes the governing fastener demand. Confirm actual coordinates, load direction, plate stiffness, preload and slip assumptions, bearing and tear-out, prying, fastener allowables, fatigue, and applicable requirements before release.