Documentation/Modules/Weld Group Analysis

Weld Group Analysis

Weld strength and stress distribution

Standards catalog

Validation: beta · Method band: formula

Open calculator

Indicative method: Indicative closed-form or numerical model

Assumptions

  • Linear elastic material behavior unless noted otherwise.
  • User is responsible for load combinations and load factors per the selected design code.
  • Design standard (US/EU/ISO) sets unit defaults and screening check labels — not a full code worksheet.

Limitations

  • Professional screening / indicative workspace — does not replace a licensed PE or official code compliance review.
  • Where specialized evaluators are not implemented, checks map solver outputs to catalog templates for orientation only.

Engineering checks

CheckINDUSEUISO
Throat shear utilizationimplementedimplementedimplementedimplemented
Combined throat stressimplementedimplementedimplementedimplemented
Eccentric weld group momentimplementedimplementedimplementedimplemented

Weld Group Analysis (welds) — beta

Purpose

Analyze weld groups under direct shear, torsion, and eccentric loading by computing throat shear stress distribution and combined throat stress utilization per AWS D1.1 and EN 1993-1-8 screening methods.

Physics & theory

Fillet welds are sized by effective throat for equal-leg fillets. Throat area resists shear; normal stress on throat is often neglected for fillet welds in simplified analysis. For a weld group of total throat area , direct shear is .

Eccentric load creates moment resisted by weld group polar moment about the group centroid: combined shear . Common patterns (rectangle, circle, line) have tabulated formulas. Allowable throat shear is typically (AWS) or partial factor per EN.

Connections transfer load through bearing, shear, tension, and friction paths depending on joint configuration. Preload in bolted joints reduces joint separation and can allow friction to carry shear; without adequate preload, bolts carry full shear in bearing against hole walls.

FEM-based bolt analysis resolves member and bolt stiffness for load sharing; VDI 2230 provides a systematic worksheet for high-fidelity preloaded joints including embedding loss and tightening scatter.

Governing equations

Numerical method

Closed-form throat shear for standard weld group geometries. Centroid and polar moment computed from weld segment coordinates. Combined stress checked against code allowable; eccentric moment from load offset.

Inputs

ParameterDescription
Weld segmentsLength, position, leg size
Applied shear , moment Loading
EccentricityLoad offset from centroid
Electrode strength Weld metal ultimate
Design codeAWS D1.1 or EN 1993-1-8

Outputs

  • Throat shear components, combined throat stress, utilization, critical weld segment location.

Design codes & checks

  • Indicative: Throat shear and combined stress
  • US: AWS D1.1/D1.1M structural welding code
  • EU: EN 1993-1-8 fillet weld design rules

Assumptions & limitations

  • Elastic distribution; no plastic redistribution in weld group.
  • Fillet welds only; groove weld tension not included.
  • Brittle fracture and fatigue of welds require separate analysis.
  • Leg size must meet minimum per material thickness tables.

References

  1. AWS D1.1/D1.1M:2020. Structural Welding Code — Steel.
  2. EN 1993-1-8:2005. Design of joints — Welded connections.
  3. Blodgett, O. W. Design of Welded Structures. James F. Lincoln Arc Welding Foundation.
  4. Shigley, J. E., & Budynas, R. G. Mechanical Engineering Design, 11th ed.
  5. PhyCalcPro verification benchmarks in src/data/verification/ where available for this module.
  6. Beer, F. P., et al. Mechanics of Materials, 8th ed. McGraw-Hill — foundational stress and deformation theory.
Maintainer note: Stress-distribution equations with room for consistency upgrades.