Is Section Modulus the same as a cross sections bending strength modulus ?

AI Thread Summary
The discussion centers on whether "Section Modulus" is equivalent to a cross section's "bending strength modulus." The ECE directive specifies a requirement for a steel beam's bending strength modulus to be at least 20 cm^3. Participants clarify that the term "bending strength modulus" likely refers to the section modulus, as it is measured in volume. There is some confusion regarding terminology, with distinctions made between flexural modulus and flexural rigidity. Overall, the consensus leans towards interpreting the directive's requirement as relating to the section modulus.
Mech King
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Is "Section Modulus" the same as a cross sections "bending strength modulus"?

Good afternoon everyone,

I am following an ECE directive that sets out the requirements for the properties of a "Rear underun protection device" for the rear of a lorry.

It states that the underun bar must consist of a "steel beam whos cross-section has a bending strength modulus of at least 20cm^3"

Are they referring to the "Section modulus"? or is what they are stating a completely differnt entity.

Trying to find the appropriate person to speak to for this directive is proving abit of a nightmare, oh the joys of bureaucracy eh!

What are your thoughts?

Mech King
 
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From the looks of the information given, I would say it is indeed the section modulus because the unit is volume.

I believe bending strength modulus is the same as flexural modulus defined as:

EI or N/m^2 * m ^4 = N*m^2

Please correct me if i am wrong, but this is my take on this.
 
Nick Bruno: No, flexural modulus of elasticity has units of Pa (pascals), as does tensile modulus of elasticity. And E*I, which has units of N*m^2, is called flexural rigidity, not the names you listed.

Mech King: I agree that "bending strength modulus" in your above post is elastic section modulus.
 


Thanks for your replies chaps,

much appreciated.

Cheers
 

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