Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Boundary condition at interface of two different materials in structural analysis module

Please login with a confirmed email address before reporting spam

Hi,

I am trying to simulate a structural mechanics problem that utilizes 3D solid stress-strain module. I have a square plate of elastomeric material having a thikness in micro meteres and on top of this elastomeric substrate I have a metalic pattern having length in cm and thickness and width in micro meters. I want to know what B.C I should use on the interconnect face that is directly in contact with the surface of the substrate. Actually there are two options free and fixed since there are no continuity conditions on interfacial boundaries in structural mechanics module.

I shall be obliged if any one can give some guidance over this issue.

Thanks

1 Reply Last Post 23.02.2013, 07:38 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 23.02.2013, 07:38 GMT-5
Hi

I'm not sure I fully understand, but by default, in geometrical union mode, two domains (sub-domains in 3.5) in mutual contact with a common boundary have continuity BC conditions across the common boundary.

Now in geometry assembly mode, this common boundary is dedoubled, one attached to each domain, and by default there is NO flux passing from one domain to the other, yiu need to define the physics in between, this can be identity pairs wih continuity, contact pairs or pairs with specific physics (COMSOl has some, you can define your own PDEs at will.

In v4, there are many more "surface" physics incuded in the standard GUI, so for these you do not even need the "asembly mode" COMSOL looks after and overides the defalt continuity law and adds its own up/down link with the appropriate physics

--
Good luck
Ivar
Hi I'm not sure I fully understand, but by default, in geometrical union mode, two domains (sub-domains in 3.5) in mutual contact with a common boundary have continuity BC conditions across the common boundary. Now in geometry assembly mode, this common boundary is dedoubled, one attached to each domain, and by default there is NO flux passing from one domain to the other, yiu need to define the physics in between, this can be identity pairs wih continuity, contact pairs or pairs with specific physics (COMSOl has some, you can define your own PDEs at will. In v4, there are many more "surface" physics incuded in the standard GUI, so for these you do not even need the "asembly mode" COMSOL looks after and overides the defalt continuity law and adds its own up/down link with the appropriate physics -- Good luck Ivar

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.