General stiffness¶
The general stiffness property implements a linear elastic stiffness between source and target interface.
Definition¶
Source and target interfaces can be chosen arbitrarily.
Parameters¶
General stiffness link properties can be parametrised in two modes: simple and advanced, which are described in the following.
Advanced mode¶
In the advanced mode, the user is prompted to supply four stiffness matrices, \(\mathbf{K_{SS}}\), \(\mathbf{K_{ST}}\), \(\mathbf{K_{TS}}\), and \(\mathbf{K_{TT}}\). Following equation describes how the stiffness matrices define a coupling between the target and source interface, denoted by subscript \({T}\) and \({S}\), respectively.
A list of symbols is shown in following table.
| Symbol | Dimension | Meaning | 
|---|---|---|
| \(\mathbf{F_T}\) | \(\in\mathbb{R}^{6\times 1}\) | Load vector to target interface | 
| \(\mathbf{F_S}\) | \(\in\mathbb{R}^{6\times 1}\) | Load vector to target interface | 
| \(\mathbf{y_T}\) | \(\in\mathbb{R}^{6\times 1}\) | Displacement vector of target interface | 
| \(\mathbf{y_S}\) | \(\in\mathbb{R}^{6\times 1}\) | Displacement vector of source interface | 
| \(\mathbf{K_{TT}}\) | \(\in\mathbb{R}^{6\times 6}\) | Stiffness matrix coupling target displacement and target load | 
| \(\mathbf{K_{ST}}\) | \(\in\mathbb{R}^{6\times 6}\) | Stiffness matrix coupling target displacement and source load | 
| \(\mathbf{K_{TS}}\) | \(\in\mathbb{R}^{6\times 6}\) | Stiffness matrix coupling source displacement and target load | 
| \(\mathbf{K_{SS}}\) | \(\in\mathbb{R}^{6\times 6}\) | Stiffness matrix coupling source displacement and source load | 
Simple mode¶
In the simple mode, a symmetric behaviour between target and source interface is implied. The four stiffness matrices are replaced by a single stiffness matrix \(\mathbf{K}\) and applied to the coupling equation as follows: