Wall to wall connections - eesd-epfl/OpenSees GitHub Wiki
Wall-to-wall connections can be modelled as rigid connections if the user is not interested in capturing the possible failure of the connection for the opening of a vertical crack between two walls. In this case a contraint of the type "equalDOF" can be appied between the nodes of the two façades, or simply the same node, with adequate offsets, can be connected to the elements of different façades.
On the other hand, if the user wants to capture a possible failure of wall-to-wall connections, they can be modelled through zero-length elements to which a proper uniaxial material model is attached. Any uniaxial material featuring a finite, non-zero tensile strength and proper crack-closure description is suitable, for example Concrete02.
Alternatively, a very simple one, developed for the use in a wall-to-wall interface, is provided in the library TensionDamage1d (download binary 64bit for Windows or build your own). The material features a linear elastic behaviour in compression, with no crushing, and a finite tensile strength with exponential softening. The syntax is:
uniaxialMaterial TensionDamage1d $matTag $k $Ft $GfI
Where:
| matTag | material tag |
| k | stiffness of the interface |
| Ft | tensile (force) capacity of the interface |
| GfI | area under the force-displacement curve (fracture energy in mode I multiplied by the tributary area) |
The material can however describe also a stress-strain relation, where the parameters would represent material stiffness, tensile strength and fracture energy divided by the integration length. As for application in a zero-length interface the material model must be formulated in terms of force-displacement; the (penalty) stiffness and the force capacity can be obtained integrating the properties of the material along a certain area attributed to the zero-length interface.
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