This example uses the old, Gauss point based, approach to active tension modelling to simlate the active contraction and relaxation of a single element, tri-cubic Hermite, rectangular cartesian cube.

In this simulation, the initial geometry is deformed purely by the generation of active tension within the cardiac tissue. One face of the cube is fixed to move only within its plane (the y-z plane) and a node on the opposite face is constrained to slide along the x-axis.

The level of activation is controlled via the ipacti file, which sets the level of activation to use for the current solution. This animation shows the results from the model when the activation level rises from zero to 1.5 and then returns to zero. The 3 pairs of cones illustrate the principal strains, which can clearly be seen well aligned with the fibre, sheet, and sheet-normal axes, with red indicating extension and blue compression.

Cool animation

draw.com can be used to visualise the results of this simulation.