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Predeformed geometrically exact beam model for a dynamic‐response prosthesis
Author(s) -
Scheiterer Eduard S.,
Leyendecker Sigrid
Publication year - 2021
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.202000152
Subject(s) - prosthesis , computer science , rigidity (electromagnetism) , representation (politics) , structural engineering , work (physics) , beam (structure) , gait , simulation , mechanical engineering , mechanics , engineering , physics , artificial intelligence , physical medicine and rehabilitation , medicine , politics , law , political science
Abstract Clinical trials have shown that the storage and release of energy in prosthetic feet plays a major role in the resulting walking comfort for the patient. In comparison to rigid multi‐axis prosthetic feet, dynamic‐response prosthetic feet show good energy storage and release capabilities and thereby increase the walking comfort of the patient. To accurately simulate such a prosthesis in a gait cycle simulation, its model has to represent the deformation energy as accurately as possible. Based on the theory of predeformed geometrically exact beams [1], this work proposes a model for a carbon spring foot prosthesis, continuing the work from [3]. The model is based on the Össur Vari‐Flex®, which has been non destructively reverse engineered resulting in a CAD representation and various parameters. Additionally, the parameters for density and elasticity and shear modulus were refined with parameter optimisation [4]. The geometrically exact beam model of the prosthesis offers a good representation of the deformation energy for large deformations occurring during the gait cycle while reducing the computational cost. The model's implementation is validated numerically and a brief mesh study is performed. The next step is the consideration of epistemic uncertainty and to investigate its influence on the prediction of the energy storage and release capabilities of the prosthesis.