How to Maintain Accurate Bone Geometries in Your FEA Mesh
FEA mesh is the practical application of the finite element method (FEM), nowadays used intensively by engineers and scientists to mathematically model and numerically solve very complex problems in a wide range of applications.
If you are facing the problem of meshing a complex geometry of biological structures of human body, you probably know the necessity of having accurate geometrical modelling and mesh generation and are well aware of how this would impact the result of your computational analysis.
The Materialise team is familiar with the challenges that many of you are facing and the computational efforts which you undertake to get accurate results which can be validated against experimental data. In order to address these challenges, we joined forces with our users to identify solutions for the challenges they are facing. This has resulted in a series of new and improved functionalities which are available in the new Materialise Mimics Innovation Suite.
Post-doctoral researcher Dr. William Parr from New South Wales University, Australia has addressed the technical difficulties involved in maintaining accurate bone geometries while creating an FEA mesh in an engaging webinar. He shares the research he has been doing, along with the challenges he has been able to overcome with improved functionalities in the Mimics Innovation Suite. The main challenge in his study is to produce a uniform mesh with approximately 3 million elements for the ankle bone. Using previous versions of Mimics, this has required a huge amount of computational time and effort to produce a mesh with suitable quality and numbers of volume elements to run stable FE simulations. By using version 19, Dr. Parr has overcome these difficulties. He has been able to maintain the geometry, create a refined mesh with under 3 million volume elements and, furthermore, run a robust FE simulation.
Bone is a dynamic tissue that changes throughout our lives. These changes occur through remodeling as a result of changes in the biomechanical environment such as: changes in exercise regime; injuries, either to the bone or soft tissue acting on the bone; surgery and implantation of stiff metallic medical devices, for example joint replacements. Due to the complexity in geometry, scientists find it extremely difficult to model the porous structure of cancellous bone. Dr. Parr’s study generates reliable computational models, which allow him to test hypotheses around how bone geometry is related to bone mechanical environment.
Some of the work performed by Dr. Parr has been bridging the gap between the micro and macroscopic levels of bone and specifically on bone biomechanics and morphology; specifically by modelling bone morphology and biomechanics accurately on a micro and macroscopic level. The interest in the microscopic level is due to our desire to know what is going inside the bones, i.e. what’s happening to the trabeculae during bone loading? However, in the FEA method we need to be certain of accuracy: firstly material properties, secondly boundary conditions and thirdly, and importantly, the geometry. Modelling an accurate geometry depends on two main factors: the resolution of the initial images, which is advancing nowadays with the increasing availability of micro-CT; and the computational tools which can handle working efficiently with the large datasets resulting from the high resolution imaging.
The team of engineers and researchers at Materialise are working closely with customers to improve the functionalities of the software to help you address the challenges you face in building your complex biological structures, and minimize the computational efforts you need to take and get accurate FEA results. Please take a moment to watch the recording of the webinar and don’t hesitate to contact us if you need more information.