Substructuring and periodic materials

  1. Anonymous

    Hello All


    I would like to ask , what is the distinction between substructuring and periodic modelling ? when do we use each ? Since  In Substructures , we make one super element from a part of the mesh , that is repeated , so , for example for a corrugated structure , which is a better selection ?

  2. Anonymous

    Thank you in Advance for your attention

  3. Wenbin Yu

    substructuring is a fem technique, basically, divide a structure into several subdomains. For each subdomain, it is possible to relate the displacements with forces for the boundary nodes, so called static condensation. For this purpose, the subdomain becomes also so-called a super element. So a substructure will have a defined domain (in terms of real dimensions of the structure), and constitutive relations will be in the type of F=Ku, with F as forces along the boundaries, u as the displacements along the boundaries. For each structural analysis, a substructuring analysis for each domain must be carried out.

    periodic materials, can be analyzed using substructuring technique. I believe you are referring to use micromechanics to analyze periodic materials. Then they are different in the following aspects:

    1. microstructure implied has zero dimensions in the real original structure.

    2.  constitutive relations are in terms of stress and strain averaged over the microdomain.

    3. micromechanics can be completely separed from the macroscopic analysis. Which means we could have one micromechanical analysis, but multiple macroscopic analysis. 

  4. Anonymous

    Thank you so much dear Professor


    your adivces have had always the highest credibility and value for me 


    Best Regards