Johnson–cook Model Combined With Cowper–symonds Model for Bone Cutting Simulation With Experimental Validation

Abstract

Constitutive models are widely used to predict the mechanical behavior of different kinds of materials. Although the Johnson–Cook model for bovine bone and Cowper–Symonds model for human thoracic rib and tibia was developed, the predictability of these models was found good only at particular strain rates. This study addresses this lack of information by investigating the Cowper–Symonds model, Johnson–Cook model, and Johnson–Cook model combined with Cowper–Symonds model at different strain rates to utilize in the bone cutting simulation. Specimens prepared using two rear femurs harvested from a 3.50-year-old bovine were investigated at different strain rates (0.00001–1/s). A comparative study made among the stresses predicted from these models showed 29.41%, 10.91%, and 11.11% mean absolute percentage errors using Cowper–Symonds model, and 2.03%, 7.19%, and 3.62% mean absolute percentage errors using Johnson–Cook model, respectively, at 0.0001, 0.001 and 1/s strain rates. However, the Johnson–Cook model combined with the Cowper–Symonds model predicted the stress with a maximum of only 2.03% mean absolute percentage error. The potential of each model to utilize in the orthogonal bone cutting was also evaluated using Ansys® and found that the combined model predicted the cutting force close to experimental cutting force with minimal error (5.20%). The outcomes of this study can be used in the surgical practice and osteotomy procedure before commencing actual surgery.

An in-silico bone drilling protocol to control thrust forces using finite element analysis coupled with the constitutive models

“…The parameters involved in these constitutive models were determined from the tensile test. 24 The lowest strain rate of 10 −5 /s was used as a reference strain rate as followed in the earlier study. 25…”

“…Tensile tests with different strain rates (10 −5 /s, 10 −4 /s, 10 −3 /s and 1/s) were conducted using the Instron ® 3369 universal testing machine (Figure 2(b)), and then the model parameters were determined. 24 Totally, 16 specimens were considered for the tensile tests. To avoid slippage, strain rates lesser than or equal to 1/s were only considered.…”

Biomechanical evaluation of different strain judging criteria on the prediction precision of cortical bone fracture simulation under compression

“…Early numerical research predicted the fracture load in the cortical bone structure by developing a linear elastic fracture model ( Stitzel et al, 2004 ; Ural and Vashishth, 2006 ). With the development of fracture mechanics, the elastic-plastic fracture model was used to perform cortical bone fracture, which simulated the failure process by describing the change in the mechanical behavior during crack propagation ( Prasannavenkadesan and Pandithevan, 2021 ; Remache et al, 2020 ). The cortical bone fracture can also be simulated using the continuum damage mechanics theory and the extended finite element method.…”