For the realization of a novel hydraulic knee joint, Streifeneder ortho.production broke new ground with ANSYS FEM simulation.
The aim of the development of the knee prosthesis KINEGENstream, which is equipped with new technical features, is to cover a further user area with higher degrees of activity (mobility grade 3 - 4, body weight: up to 150 kg). Thus, this prosthesis is intended for the unrestricted outdoor walker with unlimited walking and mobility requirements.
In order to determine and evaluate the deformation and stress situation of critical components of the knee prosthesis, the tests were reproduced using FEM simulations in the ANSYS® Workbench™ environment.
Critical areas were identified and concrete improvements of the structure were implemented based on the findings. The number of necessary test bench trials has been reduced.
In order to expand the range of applications for knee prosthesis wearers, Streifeneder ortho.production GmbH has launched a newly developed hydraulic knee joint. It is intended for persons up to a body weight of 150 kg and with a high degree of activity. In contrast to previous developments, this is a knee joint with a multi-joint axis arrangement. In order to investigate the fatigue strength behavior of the joint, test bench trials with 3x106 load changes were carried out.
The number of necessary test bench trials could be reduced because the tests are carried out with knee joints that have been improved in advance by simulation. The use of cost-intensive materials for production could be avoided. It was not only the simulation results that convinced Streifeneder’s employees. The intuitive program handling and the large number of options for processing results in ANSYS Workbench also meant that they were able to quickly achieve efficiency gains for product development through the consistent use of simulation techniques.
In order to determine and evaluate the deformation and stress situation of critical components of the knee prosthesis, the tests were simulated using FEM simulations in the ANSYS Workbench environment. The mobility of the individual components to each other was ensured at the articulation points by means of non-linear friction-free contacts. The essential components of the test bench were considered idealized in the FE-model.