Two parallel line welds

Symmetric weld-group line load

Inputs

Length of each line weldLEqual effective length of each of two parallel line welds in the symmetric model.

Center spacing between linesbPerpendicular distance between the two equal parallel weld centrelines.

Declared in-plane direct forceFKnown resultant in-plane force magnitude distributed uniformly only in the displayed line-weld model.

Declared torsional momentMIn-plane torsional-moment magnitude about the symmetric weld-group centroid.

Results

Total effective line length

200

Unit-throat polar line property

486,667

mm³

Farthest endpoint radius

64.031

Direct shear line load

N/mm

Endpoint torsional line load

105.26

N/mm

Quadrature line-load magnitude

121.16

N/mm

Ltotal = 2L; Ju = Lb²/2 + L³/6; qdirect = F/Ltotal; qtorsion,end = M·rmax/Ju

A first-pass number, not a code check, certification, or approval. Read the method and its limits below. What this is and is not.

Calculation snapshot

Symmetric weld-group line load

Formula version 2.0.0

Conditions

Length of each line weld	100
Center spacing between lines	80
Declared in-plane direct force	12000
Declared torsional moment	800

Calculated response

Total effective line length	200 mm
Unit-throat polar line property	486,667 mm³
Farthest endpoint radius	64.031 mm
Direct shear line load	60 N/mm
Endpoint torsional line load	105.26 N/mm
Quadrature line-load magnitude	121.16 N/mm

Method

Ltotal = 2L · Ju = Lb²/2 + L³/6 · qdirect = F/Ltotal · qtorsion,end = M·rmax/Ju

Source

Shigley's Mechanical Engineering Design — weld groups by the unit-area method:

Boundaries

Two equal parallel line welds
Symmetric centroidal geometry
Unit-throat line-property method
Declared in-plane direct force and torsional moment

This printout is a record of displayed inputs and deterministic formula output. It is not an approval, certification, or engineering conclusion.

Nearby: Milling removal rate · Drilling speed & time · Turning material removal · Milling cutting parameters

Method

Formula, when it applies, and when it does not

Calculate unit-throat direct shear flow and endpoint torsional line-load magnitude for a symmetric pair of parallel line welds under in-plane force and torsional moment.

Ltotal = 2L; Ju = Lb²/2 + L³/6; qdirect = F/Ltotal; qtorsion,end = M·rmax/Ju

When

Two equal parallel line welds
Symmetric centroidal geometry
Unit-throat line-property method
Declared in-plane direct force and torsional moment

Don’t

This is a two-equal-parallel-line, unit-throat preliminary weld-group model. The displayed quadrature magnitude is not a maximum vector resultant or code check. It does not model arbitrary weld geometry, throat/leg sizing, directional loading, vector addition at endpoints, eccentric force geometry, bending, fatigue, residual stress, distortion, heat input, weld procedure/quality, code provisions, capacity, safety, or approval.

Shigley's Mechanical Engineering Design — weld groups by the unit-area method