Enter the cross-sectional area, the characteristic tensile strength, the depth of the beam, and the depth of the neutral axis to determine the ultimate moment.

Ultimate Moment Formula

The following equation is used to calculate the Ultimate Moment.

Mu = A * T * (D – (a/2) )

  • Where Mu is the ultimate moment
  • A is the cross-sectional area
  • T is the tensile strength of the material
  • D is the depth of the beam
  • a is the depth of the neutral axis

What is an Ultimate Moment?

Definition:

An ultimate moment is a measure of the of the total moment acting on a beam when it is subject to it’s maximum capacity.

How to Calculate Ultimate Moment?

Example Problem:

The following example outlines the steps and information needed to calculate Ultimate Moment.

First, determine the cross-sectional area. In this example, the cross sectional area is .45m^2.

Next, determine the tensile strength at capacity. This is found to be 100,000 pascals.

Next, determine the depth of the beam. This is measured to be 2m.

Next, determine the depth of the neutral axis. This is measured to be 1.5m.

Finally, calculate the ultimate moment using the formula above:

Mu = A * T * (D – (a/2) )

Mu = .45 * 100,000 * (2 – (1.5/2) )

Mu = 56,250 N-m.