# Flat Plate Welds

on . Posted in Welding Engineering

## Axial Force on Butt Weld formula

 $$\large{ \sigma = \frac{ P }{ L \; t } }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ L }$$ = length of weld

$$\large{ t }$$ = plate thickness

$$\large{ P }$$ = total axial force

## Axial Force on Fillet Weld formula

 $$\large{ \sigma = \frac{ P }{ L \; \left( h_1 \;+\; h_2 \right) } }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ L }$$ = length of weld

$$\large{ P }$$ = total axial force

$$\large{ h_1 }$$ = weld penetration

$$\large{ h_2 }$$ = weld penetration

## Bending Moment on Butt Weld formula

 $$\large{ \sigma = \frac{ M }{ L \; t } }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ M }$$ = bending moment

$$\large{ L }$$ = length of weld

$$\large{ t }$$ = plate thickness

## Bending Moment on Fillet Weld formula

 $$\large{ \sigma = \frac{ 3 \; t \; M }{ L \; t \; \left( 3\; t^2 \;-\; 6 \; t \; h \;+\; 4 \; h^2 \right) } }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ M }$$ = bending moment

$$\large{ L }$$ = length of weld

$$\large{ t }$$ = plate thickness

$$\large{ h }$$ = weld thickness

## Axial Force on Angled Butt Weld formulas

 $$\large{ \sigma = \frac{ P \; cos \; \theta }{ A } }$$ $$\large{ \sigma = \frac{ P \; \left( cos \; \theta \right)^2 }{ t \; L } }$$ $$\large{ \theta = \frac{ P \; sin \; \theta }{ A } }$$ $$\large{ \theta = \frac{ P \; sin \; \left(2 \;\theta\right) }{ 2 \; t \; L } }$$

### Where:

$$\large{ \tau }$$ (Greak symbol tau) = shear stress

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ \theta }$$ (Greek symbol theta) = angle of weld to load

$$\large{ L }$$ = length of weld

$$\large{ P }$$ = total axial force

$$\large{ A }$$ = weld throat area

$$\large{ t }$$ = weld throat thickness

## Bending Moment on Butt Weld formula

 $$\large{ \sigma = \frac{ M }{ E } }$$ $$\large{ \sigma = \frac{ 6 \; M }{ L \; t^2 } }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ M }$$ = bending moment

$$\large{ L }$$ = length of weld

$$\large{ E }$$ = modulus of weld section

$$\large{ t }$$ = weld throat thickness

## Torsion Moment on Butt Weld formula

 $$\large{ \tau = \frac{ T }{ E } }$$ $$\large{ \tau = \frac{ T }{ \delta \; L \; t^2 } }$$ $$\large{ \delta = \frac{ L }{ 3 \; L \;+\; 1.8 \; t^2 } }$$

### Where:

$$\large{ \tau }$$ (Greak symbol tau) = shear stress

$$\large{ L }$$ = length of weld

$$\large{ E }$$ = modulus of weld section

$$\large{ \delta }$$ (Greak symbol delta) = section modulus factor

$$\large{ T }$$ = torque force

$$\large{ t }$$ = weld throat thickness

## Bending Moment on Butt Weld formula

 $$\large{ \sigma = \frac{ M }{ E } }$$ $$\large{ \sigma = \frac{ 6 \; M }{ L^2 \; t } }$$

### Where:

$$\large{ \sigma }$$ (Greek symbol sigma) = stress in weld

$$\large{ M }$$ = bending moment

$$\large{ L }$$ = length of weld

$$\large{ E }$$ = modulus of weld section

$$\large{ t }$$ = weld throat thickness