Teaching & practical trainings
Lectures
Lectures by Prof. Dr.-Ing. M. Staat are no longer offered.
The lecture Biomechanics will be offered by Prof. Kirstin Albracht from WS2019/20.
Lecture by Prof. Dr med. W. van Laack
Practical training in biomechanics
Dates for biomechanics practical training in the winter semester
FEM1: Experiment Finite Element Method (piston)
FEM2: Experiment Finite Element Method (beam)
FEM3: Experiment finite element method (bones)
DMS: Strain gauge experiment
OPT: Optical stress analysis experiment (stress optics & digital image correlation)
DIC: Digital image correlation (presentation on the biaxial measuring system)
Start of practical training: mid-October
Please register for the practical training in ILIAS!
Biomechanics practical training in ILIAS
You can find the current list of dates on ILIAS!
Experiments: FEM1, FEM2 and FEM3
Location: 01C09 (C-Wing, Technomathematics)
Time: Thurs. 10:15-12:15
Duration: 2h
Number of participants: max. 12 students per session
Experiments: DMS, OPT
Location: 01E15
Time: Fri 10:15 - 12:15 (OPT also Thurs.)
Duration: 2h
Number of participants: 6 students (2 groups of 3 students each)
Experiments: DIC
Location: 01E15
Time: Fri. 10:15 - 12:15
Duration: 1.5h
Number of participants: 6 students
Supervisor:
Mr Horbach (DIC)
Mr Gatzweiler (FEM1, FEM2, FEM3, DMS, OPT)
Fig.: Application example 3D-DIC on the hip joint, loading device (left), geometry acquisition (centre), result display of the displacement (right).
When developing and designing prostheses, medical instruments, sports and training equipment, it is essential to know the forces and stresses that occur. In practical training, students learn about methods that can be used to record these parameters. The content of the practical course is the use and comparison of different methods for mechanical stress analysis using the example of a beam as a 4-point bending test.
The loading device of the four-point bending test, as it is used in all experiments during practical training:
Strain gauge experiment [DMS]
Learning content:
Design and function of strain gauges, strain gauge types, possible applications, application of a strain gauge on a beam (Fig. above/left), Whaetstone's measuring bridge, temperature compensation, connection to a measurement data acquisition system, Hooke's law
Optical stress analysis test [OPT]
Learning content:
Voltage optics; how the transmitted light polariscope works, voltage optics basics, isochromats, atomic number, optically active substances, linearly and circularly polarised light, main equation of voltage optics, voltage optics analysis on a beam made of optically birefringent material (Makrolon/Bayer) in a bending test, comparison of strain gauge/voltage optics results.
Digital image correlation (DIC), theoretical background, target function, hardware components for DIC, calibration, setting the depth of field, preparing the measurement sample with a speckle pattern, image acquisition at different load levels, masking out the area of interest, setting starting points for point tracking, displaying results.
![Finite Elemente Methode [FEM2], Balken](/fileadmin/_processed_/e/c/csm_FEM_Balken_934ad91eec.png "FEM Balken")
![Finite Elemente Methode [FEM2], Balken](/fileadmin/_processed_/d/3/csm_Balken_FEM-Lines_0658934a9e.png "Balken FEM-Lines")
Learning content:
Stress analysis on a beam in a bending test, using the Salome pre- and post-processor, drawing the geometry with the graphics editor, using the mesh generator (Mesher), defining the boundary conditions, using the Code_Aster command editor EFICAS, displaying the results with the post-processor (see illustration on the right), comparing the results with those of the practical tests (strain gauge/stress optics).
Test Finite Element Method [FEM3], bone
FEM analysis of a femur prepared with bone cement (PMMA).
The experiment description and the geometry dataset are available for download in the ILIAS e-learning area.
![Finite Elemente Methode [FEM3], Knochen](/fileadmin/_processed_/e/9/csm_Bildschirmfoto_2016-07-12_um_12.43.26_fc31c3ec37.png "Knochen")
Learning content:
Preparation of geometry data from CT images (DICOM format) using segmentation software. Import of the geometry into the preprocessor (SALOME) and creation of element groups for the definition of boundary conditions (load case). Material assignment to the individual bone layers. Editing the command file for the FEM solver (Code_Aster). Post-processing (result visualisation) in ParaVIEW. Creation of sectional planes to visualise the stress distribution in the bone. Interpretation of the results, i.e. what effects does the treatment of the femoral neck with bone cement have on the stress distribution in the bone.
Learning content:
Calculation of a motor piston with Salomé and Code_Aster, import of geometry data from a CAD programme through a STEP interface file to Salomé, networking of geometry, definition of boundary conditions and material data, use of the Salomé Wizard (assistant), display of results in the post-processor.
Further information can be found under the tab "Information on the FEM software used" at the bottom of this page!
Note: As the "Piston" experiment [FEM1] is more suitable for getting started with the FEM than the "Beam" experiment due to the CAD import (import of geometry data) and the use of the wizard, this experiment is carried out first.
Further information
More detailed information on the software used for the FEM experimentscan be found in the "FEM practical training" tab. Only the beam, piston and bone (femur) experiments are worked on in the biomechanics practical training. For the FEM experiments, each student is provided with an experiment station/computer system (PC seminar room of the Technomathematics department). You will need your FH login (name/password) to log on to one of the PCs.
If you have a notebook with a 64bit processor, you can also carry out the FEM experiments on it. Your (Windows) installation will remain intact, you will then work with a Linux Live DVD, a Linux Live USB stick or with a Linux emulation (VM-Ware/OpenBox). Please ask Mr Gatzweiler before the test day.
It is not necessary to print the test descriptions. It is sufficient if you read through the first pages of the description, i.e. the theoretical part, before the experiments. The experiment descriptions will be handed out by us free of charge on the day of the experiment.
It is not necessary to write a practical training report after the individual experiments; we emphasise active participation in the practical training. At the end of the entire practical training, however, a practical training evaluation (see evaluation sheet below) should be processed and completed, where, for example, the different methods for stress analysis are finally compared with each other. This evaluation must be submitted personally by each student in order for the practical training to be recognised.
Download the experiment descriptions
It is not necessary to print the experiment descriptions. It is sufficient to read through the first pages of the description, i.e. the theoretical part, before the experiments (in the PDF reader). The password to open the files will be announced at the preliminary discussion.
The instructions will be handed out free of charge before the experiments!
ATTENTION: The experiment instructions will only be made available in ILIAS! Finite element method 1, experiment "Piston"
-> FEM1 (PDF file 5.4 MB)
-> Video of the piston/piston experiment
-> Template LinStatics3D.comm
Finite element method 2, "Beam" experiment
-> FEM2 (PDF file 19.2 MB)
-> Video of the Beam/Beam Part 1 experiment
-> Video of the Beam/Beam Part 2 experiment
Finite element method 3 "Bone" experiment
-> FEM3 (PDF file 19.2 MB)
Strain gauge experiment
Experiment description
-> DMS (PDF file 6.2 MB)
Test presentations
-> DMS-Allgemein (PDF file 4.9 MB)
-> DMS-Applikation (PDF file 15.5 MB)
-> DMS-Wheatstone (PDF file 2.2 MB)
Videos on the Wheatstone measuring bridge:
-> Link to the videos quarter/half and full bridge
Optical stress analysis test
-> OPT (PDF file approx. 18.7MB)
Digital image correlation experiment
-> Download will be activated shortly!
Evaluation sheet
ATTENTION: A final voluntary test will only take place online in ILIAS at the end of January!
This final evaluation form must be completed and submitted in person by the beginning of the SS at the latest.
> Evaluation (PDF file 512kB). If the measurement results have not been recorded, you can refer to the following results data for evaluation:
> Measurement results ( PDF file 2.4MB)
Practical training Finite Element Method (FEM)
For Master's students of technomathematics and biomedical engineering, accompanying the lecture "Finite Element Method FEM", stress analysis using the finite element method.
Number of experiments: 7
Duration per experiment: approx. 1.5 to 2.0 hours (depending on the experiment)
Number of participants per experiment: 12
Number of workstations: 12 (PC seminar room 01C09 in the technomathematics wing)
Dates by arrangement with Mr Gatzweiler (gatzweiler(at)fh-aachen.de or office 01E09).
The practical training can also be carried out on different days of the week if the PC seminar room 01C09 is free, see room allocation plan in CAMPUS. Supervision is possible on Thursdays and Fridays. On the other days you would have to work independently.
Link to eLearning ILIAS Link to eLearning ILIAS
If you have any questions, please email: gatzweiler(at)fh-aachen.de
Programme used:
Salome as pre- and postprocessor
(from 2016 ParaView as postprocessor)
and
Code_Aster as solver
Platform: Linux (Debian32bit/Ubuntu64bit), alternatively also with VMWarePlayer or Virtual Box (Linux emulated) under Windows or Mac OS as well as directly with the live DVD. A live USB stick based on Ubuntu64 is also available. If you are interested, you can have the DVD or USB stick copied at the Biomechnanik laboratory.
An *.ova file (so-called appliance, approx. 8 GByte) is now available, which you can import directly into the VirtualBox. All you need to do is install ORACEL's VirtualBox on your Windows, Linux or Mac computer and then import the appliance. The entire working environment, i.e. Ubuntu 14.04 including all applications (current versions), is then available to you for practical training. Further information in ILIAS.
Learning objectives: Using the preprocessor (graphics editor), entering geometry and material data, selecting elements, meshing. Definition of boundary conditions and loads, editing the FEM command file, control options, starting the FEM analysis. Options for displaying the results of the post-processor. Handling interface files, import/export.
Tutorial: You can watchvideos(Faculty 9/Gatzweiler) on the FEM experiments in the e-learning area, ILIAS (login with your FH password), or download them directly. You will find the link to the download at the bottom of the individual experiments.
Preparation for practical training
For an introduction to the use of Salome and Code-Aster, we recommend that you watch the tutorial (Flash video) for the respective experiment (the evening before). The videos are adapted for a resolution of 1024*768. The comments are written in German.
If you would like to work with Salome/Code_Aster on your own computer (live DVD, hard disc installation or VMWare), you can download the detailed experiment descriptions (PDF file, use the "BioPrak-login" password to open the file!A description of the working environment (CAE-Linux/Salome) can be found on the first pages of the experiment description for the "bending beam". You do not need to print out the experiment instructions; we will hand them out at the beginning of the practical training.
Download the experiment descriptions
A complete handbook for the FEM practical training can be found after group registration in ILIAS eLearning, see link above.
You do not need to print the instructions, you will receive a copy before the practical!
Forgotten your password? Email to: gatzweilerfh-aachen.de
Experiment 1 / Practise 1: Motor Piston / Motor Piston
Calculation of a motor piston with Salomé and Code_Aster. Import of geometry data from a CAD programme through a STEP interface file to Salomé.
Calculation of a motor piston with SALOME and Code_Aster. Import of the geometry data from a CAD programme using a STEP Interface file.
- Tutorial_Piston (Video)
- PDF Tutorial Piston multilingual (see ILIAS)
Experiment 2: Bending beam (four-point bending test)
Stress analysis on a bending beam made of optically birefringent material. During practical training in biomechanics, this beam is also analysed using other methods, such as stress optics and strain gauge technology. The results and the advantages and disadvantages of these methods are then compared with each other.
Experiment 3: Tuning fork/modal analysis
Experimental modal analysis can be used to describe components in terms of their structural-dynamic properties -frequencies, damping and vibration modes. In this practical part, some aspects of experimental modal analysis are presented without in-depth mathematical derivations.
- Tutorial tuning forksfork
- PDF tutorialtuning fork
Experiment 6: Contact analysis
A steel cylinder rests on a plastic cube with a normal force of 100 N (/d)
Experiment 7: Static analysis on bone
FEM analysis on a femur prepared with bone cement (PMMA).
The experiment description and the geometry dataset are available for download in the ILIAS e-learning area.
![Finite Elemente Methode [FEM3], Knochen](/fileadmin/_processed_/e/9/csm_Bildschirmfoto_2016-07-12_um_12.43.26_e165c10b7f.png "Knochen")
[Experiment 8: Venturi tube] no longer part of the practical training!
ATTENTION:
Flow analyses are now carried out by Prof. Behbahani in the practical training CFD Computational Fluid Dynamics with Code_Saturne !
Flow analysis with Code_Saturne and comparison with the results from the practical training Biomechanics "Flow experiments".
This experiment is now part of the practical training "Fluid Dynamics " with Prof. Dr.-Ing.
- Tutorial-Thermal analysis
- PDF Tutorial-Thermal Analysis
Any questions or requests?
Email to: gatzweilerfh-aachen.de
Information on the FEM software used
The open source programmes Code_Aster as FEM solver (structural mechanics) and Salomé as pre- and post-processor are used in the laboratory for biomechanics at FH Aachen. Code_Aster is supported by theEDFa state-owned energy company in France, free of charge. The Code_Saturne programme, an FVM solver for fluid mechanics (CFD), has recently been added. The programmes work in a Linux environment but can also be installed under Windows or Mac OS X (Intel-based). TheCAELinux-distribution provides all the necessary software packages completely set up as a LiveDVD for download. Further information and test instructions can be found in the submenus, see below.
Code_Aster
Since 1989, EDF R&D has been continuously developing the Code_Aster structural mechanics simulation programme. This tool is widely used for expertise and maintenance of power generation and transport installations and today covers a wide range of applications:
thermomechanics - linear and non-linear problems in 3D - statics and dynamics
pressure vessels - machines - civil engineering - porous media
Developed under the quality requirements of nuclear engineering, the programme is used and appreciated in industry, research and training.
EDF R&D expects that the contributions of numerous industrial and academic research groups will flow into the development of Code_Aster and, conversely, can offer them a permanent and easily reusable working platform for their own work.
In order to reach a broad user community and thus obtain as much feedback as possible, EDF R&D has decided to make the development version of Code_Aster available on the Internet as free software. The website
http://w ww.code-aster.org/V2/spip.php?rubrique2
was launched on 19 October 2001 at the Maison de la Mécanique (Courbevoie) and provides access to the complete Code_Aster and the auxiliary programs with all source codes as well as the complete documentation and a large number of examples under the GPL licence (Gnu General Public Licence).
The site also offers an animated forum for the user and developer community and a description of the services.
Any company or organisation can offer a distribution, on its own responsibility, at market conditions and independently of EDF R&D.
We now offer free introduction and installation support.
By freely distributing a complete numerical simulation application, EDF R&D wishes to stimulate joint projects and exchanges between research and industry, for the mutual benefit of research institutes, public organisations and the entire mechanics industry.
Special thanks go to:
Special thanks go to:
Electricité de France, Recherche & Développement
1, AVENUE DU GÉNÉRAL DE GAULLE - BP 408 - F 92141 CLAMART CEDEX
Installation of SALOME & Code_Aster
The installation of Salomé, especially in conjunction with Code_Aster, is very complex, as a large number of software packages or libraries (all free, open source) have to be installed. Furthermore, these software modules must harmonise with each other by means of a specific directory structure or suitable links.
The following website provides a so-called LiveDVD (image file, approx. 1.5 GB for burning onto a DVD) for downloading, on which you can boot with a PC (at least Pentium 4, 256 MB, better 512 MB RAM) and in which the entire Salomé/Code_Aster working environment including interface (via *.med file) is available on a Linux platform.
www.caelinux.com/CMS/
Many other programmes such as the FireFox web browser or the OpenOffice office programme (as a replacement for Word with the option of creating MS Word documents) are also automatically installed on this Linux platform.
An installation script is available on the LiveDVD, which can be used to install Linux on the PC without any special prior knowledge, including all the applications listed above. A partition of at least 6GByte should be available for this. If Windows is also to be used on the PC, this operating system must already be installed. It will then be automatically recognised during the installation of Linux with the LiveDVD and a menu with the operating system selection will appear later when booting.
Important note:
If you are only working with LiveDVD, you should prepare a storage medium, e.g. a USB data carrier (memory stick or hard drive) or preferably a FAT partition of the hard drive, to back up the data created. You can find the available storage media in the directory /union/mnt/... directory.
Code_Saturne
Code_Saturneis an FVM calculation module(Finite Volume Method) developed by EDF for general problems in fluid mechanics (Computational Fluid Dynamics / CFD). It can be used to simulate incompressible or compressible flows with or without heat transport and turbulence. Special modules are available for thermal radiation, combustion (gas, coal, oil), magnetohydrodynamics and others. As with Code_Aster, SALOME is used as the pre- and post-processor. However, any other pre- and post-processor with a suitable interface can also be used.
To install Code_Saturn, we recommend the LiveDVD of the CAELinux distribution.
Download page Code _Saturne (software and documentation)
With the kind support of:
Electricité de France, Recherche & Développement
1, AVENUE DU GÉNÉRAL DE GAULLE - BP 408 - F 92141 CLAMART CEDEX
SALOME
SALOME is a free software (open source) that is used as a pre- and post-processor for numerical simulations and can be installed on various Unix derivatives, e.g. Linux. Salomé can be used in conjunction with the finite element programme "Code_Aster".
You can find more information about Salome at:
http://www.salome-platform.org/home/presentation/overview/
LiveDVD
09.03.2014 New: LiveDVD CAELinux2013 with current SALOME 6.x.x and Code_Aster on 64-bit Xbuntu-Linux distribution available!
There are three ways to work with Salome and Code_Aster with relatively little installation effort:
- Under Winows, Mac OS X or Linux: with the Virtuel Machine Player(VMWare Player) and a VMWare application file. To do this, the freely available VMPlayer software is installed on the computer system under the respective operating system( OS). After starting the VMWare Player software, the VMWare application file is loaded. CAE-Linux is then emulated in the VMWare player window and you have a complete Linux environment with all the software required to work with Salome/Code_Aster. Notes: At least 512 MB RAM. Data exchange between the installed OS and the emulated CAE Linux only via network connection (everything on one PC!) or external data carrier, e.g. USB stick. You can download the VMWare from the same website as the LiveDVD (CAELinux Beta 3b VMWare virtual machine).
- With the Live DVD: You boot with your PC or Mac (Intel-based) from the LiveDVD and the complete CAELinux operating system with all software packages is loaded into the PC. Your hard disc will not be changed. It does not matter which operating system is installed on your computer. Disadvantage: Long boot time. Data can only be backed up to floppy disc or USB memory stick.
- Installation of CAELinux with all necessary software packages for Salome/Code_Aster/Code_Saturne on the hard disc: A partition of at least 6GByte is required. CAELinux can be installed alongside other operating systems, e.g. an existing Windows operating system. When booting, you can select the operating system in a boot menu. There is an automatic installation script on the LiveDVD for installation on hard disc. Notes: The hard disc installation boots quickly and runs best during operation. All hardware such as printer, network connection, graphics card can be installed optimally and permanently. Application data can be backed up on all storage media (incl. burning to CD/DVD). This operating mode is recommended for intensive work with CAELinx and Salome/Code_Aster/Code_Saturne. Attention: Microsoft Windows does not tolerate other operating systems, therefore always install Windows first. The Windows installation is then taken into account by the subsequently installed operating systems. However, Windows would kick out previously installed operating systems by default (with regard to the boot manager).
It is also possible to use other pre-/post-processors such as GID (licence costs!), GMESH or IDEAS (Univ-file) instead of Salome. You can also install Code_Aster "on foot" under Windows, Mac OS X, Ubuntu or OpenSUSE Linux. There is a special installation package for Linux for this purpose:
On the page of the following link you can download the bootable CAELinux LiveDVD(CAELinux Beta 3b ISO image, DVD image for burning) with Salome and Code_Aster and/or the VMWare(CAELinux Beta 3b VMWare virtual machine). The download now consists of several compressed files of max. 700 MB. These are automatically reassembled after the download when unpacking. If there are problems with the download, it is possible to have a DVD copied in the Biomechanics laboratory (H202). Please bring a blank DVD disc with you. We can also send you the DVD on request (see support request below) for a fee.
After booting from the LiveDVD and then logging in (login/password root or guest), you will find icons with links to tutorials and various applications on the KDE desktop. There is also a link to start the hard disc installation script on the root desktop. Suggestions for hard disc partitioning are made first. An already installed OS does not have to be deleted and is also taken into account in the boot loader or boot menu.
ga 03/2014