Shear Flow Calculator

Calculate shear flow, shear stress, fastener spacing, torsional stress, and microchannel pressure drop for beams, shafts, and channels.

Select a tab, enter values, then calculate.

VQ/I Shear Flow

Fastener Spacing

Beam Shapes

Torsion

Microfluidic Flow

Shear flow and shear stress from q = VQ/I

Internal shear force, V

First moment of area, Q

Second moment of area, I

Thickness or width at the point, t

Fastener pitch from shear flow

Shear flow, q

Allowable shear per fastener

Number of effective fastener rows

Maximum transverse shear stress for common shapes

Cross-section Internal shear force, V

Rectangle width, b

Rectangle depth, d

Distance from neutral axis, y

Leave y blank to calculate only maximum shear stress.

Outer radius, R

Inner radius, Ri

Use Ri = 0 for a solid circle.

Flange width, b

Clear web depth between flanges, d

Web/flange thickness, t

Circular shaft torsional shear stress

Applied torque, T

Outer radius, R

Inner radius, Ri

Point radius, ρ

Use Ri = 0 for a solid shaft; leave ρ blank for the outer surface.

Rectangular microchannel flow metrics

Volumetric flow rate, Q

Dynamic viscosity, μ

Channel width, w

Channel height, h

Channel length, L

Fluid density, ρ

Leave density blank to use 1000 kg/m³.

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Shear Flow Formula

The following formula is used to calculate the shear flow.

q = (V * Q) / I

Variables:

q is the shear flow (N/mm)
V is the shear force (N)
Q is the first moment of area (mm³)
I is the second moment of area (area moment of inertia) (mm⁴)

To calculate the shear flow, multiply the shear force by the first moment of area, then divide by the second moment of area (area moment of inertia).

What is Shear Flow?

Shear flow is a measure of how a shear force is distributed over a cross-section of a beam. It is a critical parameter in the design and analysis of beams and other structural components, as it helps to determine the shear stress distribution within the material. Understanding shear flow is essential for ensuring that structures can withstand the forces they are subjected to without failing.

How to Calculate Shear Flow?

The following steps outline how to calculate the shear flow.

First, determine the shear force (V) in Newtons (N).
Next, determine the first moment of area (Q) in millimeters cubed (mm³).
Next, determine the second moment of area (area moment of inertia) (I) in millimeters to the fourth power (mm⁴).
Next, gather the formula from above = q = (V * Q) / I.
Finally, calculate the shear flow (q) in Newtons per millimeter (N/mm).
After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem :

Use the following variables as an example problem to test your knowledge.

shear force (V) = 5000 N

first moment of area (Q) = 200 mm³

second moment of area (I) = 10000 mm⁴