Discontinuities in material resistance

[Rollerblades]

Could somebody explain me what is a discontinuity in material resistance so I can modelize curve beam and plates in finite element?

 

[ishvaaag]

I have no idea on how to face your specific FEM modeling problem, but of course discontinuity in material strength is what one has at the interfaces between different structural materials put together, say, in composite members. Then satisfactory treatment of both materials in the region surrounding the interface must also be ensured (as anywhere) for the composite member perform its duty.

 

[vonlueke]

Discontinuity in material resistance would mean materials are not connected, or that stronger materials are interconnected at an interface by a weaker material. Discontinuity in material resistance at an interface can be modeled (a) by non-connected elements, (b) by freeing (releasing) resistance along any axis of discontinuous resistance at the interface, or (c) by inserting a short, reduced-stiffness beam element or a row of reduced-stiffness plate elements to create a flexible interface.

"Reduced-stiffness" in method (c) means you toggle, e.g., elastic modulus E of the interface elements to simulate any amount of fixity desired in the connection, from nearly free (like "rubber&quot to semi-rigid to completely rigid. Reducing moment of inertia I in the interface elements reduces bending stiffness; reducing area A reduces axial stiffness; reducing E reduces bending and axial stiffness. Axial stiffness is EA/L. Bending stiffness is EI/L. Good luck.