A bracket transfers an eccentric in-plane force through either a bolt group or two vertical fillet-weld lines. Resolve direct shear and the torsional contribution, then inspect vector equilibrium and the largest elastic shear demand.
• A real-time 3D view of a steel support and bracket plate with an eccentric downward load, an equal-stiffness bolt group or two vertical fillet-weld lines, colored reaction-vector arrows and the attachment centroid with reference axes, with home view, focus-selected-part, auto-rotate, expand, show/hide instrument covers and hide-labels controls. • Adjustable attachment type (bolts or welds), peak vertical load (10-150 kN), load offset from the centroid (0-300 mm), bolt rows / weld-height setting (2-4), pitch (60-140 mm) and bolt diameter / weld leg selector, with an option to cycle the applied force. • Live measurements of applied vertical load, eccentric moment magnitude, peak elastic shear demand, the sums of attachment reactions in X and Y, and the recovered resisting moment. • A Curves & measurements tab with a model response curve, parameter comparison, the model equations and snapshot measurements. • An Experiments tab with presets (concentric direct shear, large eccentricity, continuous weld group), pause and time-step controls, a model-verification bench, a timestamped event log and a copyable trial report. • A Learn & assess tab with lessons, a knowledge-check quiz with reset, and a written model-scope statement with a technical reference link.
For bolts, direct shear is Fy,direct = V/N and the polar group property is J = Σ(x² + y²). The eccentric moment M = V e adds torsional components Fxi = −M yi/J and Fyi = V/N + M xi/J, and bolt stress is the resultant divided by the single-shear bolt area. For welds, the two vertical lines have length h = (rows − 1) pitch + 40 mm and throat 0.707 times the leg; the line properties give qx = −My/Jline and qy = V/(2h) + Mx/Jline, with τ = |q|/throat. Increasing the eccentricity adds moment without changing the total vertical force.
This is an elastic in-plane group analysis only. All bolts have equal stiffness and weld lines have uniform throat. It excludes slip, prying, bolt tension, weld strength, edge distance, bearing, block shear and fatigue, and is not a connection design approval. Arrows are scaled for readability while reported reactions retain physical magnitudes.
No. Vector direction and lever arm are required, so moment equilibrium is checked about the attachment centroid using consistent millimeter units.
No. Several strength and detailing limit states, such as slip, prying, bearing, block shear, edge distance and fatigue, are intentionally outside this elastic model.
With zero eccentricity all bolts carry the same vertical force; horizontal reactions and the resisting moment are zero.
Torsional shear adds on one side of the bolt group and subtracts on the other, increasing the peak demand without changing the total vertical force.