See Embedded Elements in the Structural Mechanics Theory Chapter.
|
When the Embedded structure is a Beam interface, select whether to Suppress rotation around beam axis or not. The default is to suppress axial rotation, to avoid rigid body rotation around the beam axis.
|
When the Embedded structure is a Truss or Wire interface, enter the Axial spring constant ka, and the Transverse spring constant kt. The default unit and expression for the spring constants depend on the Connection type:
The variable <tag>.Eequ is a placeholder for the equivalent stiffness of the Truss or Wire interface, and <tag>.area and <tag>.perimeter for the cross-sectional area and perimeter, respectively. The multiplier 1e3 can be modified to tune the stiffness of the connection. Both connection types internally use the same formulation, and the spring constant per unit area is converted to a spring constant per unit length.
|
When the Embedded structure is a Beam interface and Spring constant per unit length is selected, enter the Axial spring constant ka, and two Transverse spring constants in the local coordinate system of the beam, kyl and kzl. The default expression for the spring constants is 1e3*<tag>.Eequ*<tag>.area/h^2.
The variable <tag>.Eequ is a placeholder for the equivalent stiffness of the Beam interface, and <tag>.area for the cross-sectional area. The multiplier 1e3 can be modified to tune the stiffness of the connection.
|
When the Embedded structure is a Membrane interface and Spring constant per unit surface area is selected, enter the three components of the stiffness vector in the boundary system coordinates, kt1, kt2, and kn. The default expression for each component is 1e5*<tag>.Eequ*<tag>.d/h^2.
The variable <tag>.Eequ is a placeholder for the equivalent stiffness of the Membrane interface, and <tag>.d for the thickness. The multiplier 1e5 can be modified to tune the stiffness of the connection.
|
•
|
For Linear, enter the Hardening coefficient kp. This option defines a linear hardening function kpupe, where upe is the accumulated slip. The current sliding resistance is then c = c0 + kpupe.
|
•
|
For User defined, enter an expression for the Hardening function ch. The default expression is 0[unit]*<tag>.upe. The unit depends on the Embedded structure interface, and the variable <tag>.upe is the accumulated slip. The current sliding resistance is then c = c0 + ch
|
The bond slip friction model formally describes the so-called Tresca friction, that is, the sliding resistance does not depend on the normal force acting on the interface between the Solid and the Embedded Structure. However, a Coulomb type friction model can by implemented by adding a dependence with respect to a “normal force” in the expression for the Cohesion c0. The difficulty lies in estimating the normal force
|
|