Weld Equations

The first App developed by Glendale Coding Labs, WeldEquations is an engineering calculator app that computes the section properties for typical welding patterns used in steel construction. After selecting a Weld Group, the user enters the dimensions for the depth and width.  The section properties for the Weld Group, including the area, section moduli, moment of inertia and polar moment of inertia, are instantly calculated. Sample screen shots from the App are presented below.  

First, select a Weld Group from the list.

Next, enter the Depth and Width dimensions for the selected Weld Group.  Tap "CALCULATE" and the Weld Group Section Properties are instantly computed.  These Include: The Area, The Moment of Inertia about the X and Y Axes, The Polar Moment of Inertia, The Section Moduli, The Location of the Centroid or Neutral Axis, and The Farthest Vertical and Horizontal Distances from the Neutral Axis for each quadrant.

available weld groups

METHOD OF SOLUTION

The calculations performed by the WeldEquations app are based on the Elastic Method.  This approach treats the weld as a line or a group of lines. This allows the weld group section properties to be determined without knowing the size of the weld. The section properties can be used in structural engineering formulas to determine the maximum resisting resultant force along the weld.  This resultant force is expressed in terms of force per unit length.

Since the weld is evaluated based on a force per unit length, in lieu of stresses, combining the effects from different load types (shear, axial, moment, torsion) is easily accomplished.  The applied moments and torsions can be resolved into vertical, horizontal and axial components and then vectorially combined with the directly applied shears and axial forces. All of the applied loads are assumed to act through the center of gravity of the weld. Therefore, each segment of the weld resists an equal share of the direct shear and axial forces and a proportional share of the bending moments and torsions relative to the weld segment's distance to the centroidal axis of the weld group.

The weld size can be determined by dividing the maximum resisting resultant force by the available strength of the weld.  For practicality, both weld dimensions 'd' and 'b' are limited to a minimum value of 0.25 inches and a maximum value of 100 inches.  The equations for the section properties used by the app are available for reference and manual verification by the user.

For the linear and rectangular patterns in weld groups 1-13, the location of the maximum resisting resultant force will typically occur at an end point of a weld segment or at a corner of the weld group. For each weld group quadrant, the section moduli are computed at points that are farthest from the center of gravity with respect to the X-X and Y-Y axes.

For the circular pattern in Weld Group 14, the precise location of the maximum, resultant force will be dependent on the magnitude and direction of the applied forces and, therefore, may not necessarily occur at a point on the X-X or Y-Y centroidal axes. For example, a loading condition with biaxial bending, where Mx = My, the highest stressed portion of the weld due to bending will occur at a point along an axis 45° off of the X-X and Y-Y centroidal axes.  Therefore, WeldEquations allows for the calculation of multiple Section Moduli for this weld group.  First, the Section Moduli Sx and Sy are calculated at points farthest from the center of gravity and at points on the X-X and Y-Y centroidal axes.  Second, the user may optionally provide an angle, θ, which will be used to calculate the Section Moduli about both centroidal axes at a point along the circumference intersected by a radial line located at the specified angle relative to the portion of the X-X axis in Quadrant Q1.,

APP LIMITATIONS

The WeldEquations app is intended for users that are educated and experienced with structural engineering principles and the design of welded connections. The calculations performed by the app to determine the section properties are based on the weld group dimensions, as input by the user.

The WeldEquations app does not account for various code requirements and other considerations that apply to the design of welded connections. These include, but are not limited to: the minimum size of fillet welds, the maximum size of fillet welds, the minimum length of fillet welds, the effective length of fillet welds, the thickness of the base metal, the material strength of the base metal, the joint type, joint fit-up and tolerances, constructability issues, the minimum shelf dimensions for fillet welds, termination details for fillet welds, access necessary to place welds, skewed connections, fillet welds combined with bolts or other weld types, ductility of the weld group, effects due to the load angle, fatigue and high-cycle loading, seismic loads, one-sided fillet welds when lateral deformation is not prevented, shear lag factors, effects from heat distortion due to excessive weld amounts, effects due to restraint against weld shrinkage, effects due to residual stresses in the connected elements, effects due to lamellar tearing, and the welding process used for placing the welds.

The user is responsible for evaluating these code requirements and other considerations which may affect the proportions required for a Weld Group. The section properties calculated by the WeldEquations app do not include the effect of corner radii. A 90° angle is assumed at the intersection of horizontal and vertical weld segments.

Apple Media Services Terms and Conditions &

LICENSED APPLICATION end user license agreement

Downloading, installing, accessing or using the WeldEquations and/or the WeldCalcs and/or the Table8welds Licensed Applications (Apps) requires agreement to the terms and conditions described in Apple Media Services Terms and Conditions by Apple®. This agreement incorporates additional App Store® terms and conditions relating to the licensing of App Store content including, but not limited to, the LICENSED APPLICATION END USER LICENSE AGREEMENT.  Any Glendale Coding Labs, Inc. App that you acquire via the App Store is governed by the LICENSED APPLICATION END USER LICENSE AGREEMENT (“Standard EULA”), unless Apple or Glendale Coding Labs, Inc. provide an overriding custom license agreement (“Custom EULA”).