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

  1. 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 refering to the "Section modulus"? or is what they are stating a completly 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
     
  2. jcsd
  3. Re: Is "Section Modulus" the same as a cross sections "bending strength modulus"?

    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.
     
  4. nvn

    nvn 2,124
    Science Advisor
    Homework Helper

    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.
     
  5. Re: Is "Section Modulus" the same as a cross sections "bending strength modulus"?

    Thanks for your replies chaps,

    much appreciated.

    Cheers
     
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