Applications in orthopedic and trauma biomechanics often require information on the internal forces in the body parts. Therefore, frequently Finite Element Analysis (FEA) is utilized to compute stresses and strains in the tissues.
Essential to get reliable, meaningful results out of this are realistic boundary conditions (BC). Force-wise these BCs are composed from external loadings, dynamic forces and the corresponding muscle activations for the given situation. As the AnyBody™ Modeling System is capable of providing these forces (an image visualizing this is shown to the right) it seems to be straight forward to use this data as input to a FEA.
In the following tutorial it is shown how AnyBody™ can
be used to analyze the stress state of bones. Firstly, the
built-in facilities of AnyBody™ to generate output for a FEA
are explained in general. Afterwards, an interface to ANSYS
is shown. A simple example is included which shows all the
steps from the AnyBody™ application to the nice colored
Finite Element stress plots.
These are the steps we will go through:
Generate a force output file from
AnyBody™
Export the bone surface from
AnyBody™
Mesh the bone
Apply material description and
boundary conditions
Solve the Finite Element
Model
In the first showcase only freely available software is
used to generate the mesh and solve the problem. Therefore,
also users without a commercial FEA software package can
step through it. But obviously there are plenty of
possibilities on the market to do FEA and this example
should just illustrate the flow of the task, without
claiming to do high-end FEA. In the second lesson ANSYS is
used for the FEA part and a freely available add-on to the
AnyBody™ Modeling System is used for converting AnyBody™
output to ANSYS input language.
In order to model with higher complexity and productivity (as well as user friendliness) one of our partners, Ozen Engineering Inc. has developed a tool to directly link AnyBody™ and ANSYS (Any2Ans). Further information about this can be found here .
Now it's time for Lesson 1: Export of data for FEA.