title: A modified method for assigning material properties to FE models of bones.
abstract: The aim of the present study is to compare the results from subject-specific finite element analysis (FEA) of a human femur to experimental measurements, using two different methods for assigning material properties to the FE models. A modified material mapping strategy allowing for spatial variation of material properties within the elements and Young's modulus surface corrections is presented and compared to a more conventional strategy, whereby constant material properties are assigned to each element. The accuracy of the superficial stress-strain predictions was evaluated against experimental results from 13 strain gauges and five different load cases. Both methods predicted stresses with acceptable accuracy (R(2) = 0.92, root mean square error, RMSE < 10%), with the conventional method performing slightly better. The modified method performed better in strain prediction (R(2) = 0.85, RMSE = 23% versus R(2) = 0.79, RMSE = 31%).
authors.affiliation: University of Iceland, Department of Mechanical and Industrial Engineering, Iceland. benhel@hi.is
authors.forename: Benedikt
authors.initials: B
authors.lastname: Helgason
authors.forename: Fulvia
authors.initials: F
authors.lastname: Taddei
authors.forename: Halldór
authors.initials: H
authors.lastname: Pálsson
authors.forename: Enrico
authors.initials: E
authors.lastname: Schileo
authors.forename: Luca
authors.initials: L
authors.lastname: Cristofolini
authors.forename: Marco
authors.initials: M
authors.lastname: Viceconti
authors.forename: Sigurthur
authors.initials: S
authors.lastname: Brynjólfsson
mesh_terms: D000818:Animals; D001331:Automation; D001842:Bone and Bones / Q000473:pathology*; D019245:Compressive Strength; D004867:Equipment Design; D005269:Femur / Q000473:pathology*; D020342:Finite Element Analysis; D006736:Horses; D006801:Humans; D008422:Materials Testing; D015233:Models, Statistical; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D014057:Tomography, X-Ray Computed / Q000379:methods; D016474:Weight-Bearing