From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack growth behavior for 45 deg and 90 deg crack orientations based on the ratio of the bone to cement line shear fracture properties. Gsc-b/Gsc-cl denotes the ratio of Mode II (shear) fracture toughness of bone to cement line and σsc-b/σsc-cl denotes the ratio of the shear strength of bone to cement line. The strength and toughness ratios were obtained by keeping the interstitial bone and osteon properties constant (Table ) while varying the cement line properties. The ranges of cement line properties used to obtain these ratios are marked on the graphs. The solid and hollow circles correspond to individual simulations for penetration and deflection, respectively. The solid lines represent the transition boundary between crack deflection and penetration based on the individual simulation data.

From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack driving force versus crack extension for 0 deg, 45 deg, and 90 deg cracks. Note that this plot is for Mode I fracture toughness ratio of Gnc-b/Gnc-cl=1 and tensile strength ratio of σnc-b/σnc-cl=1. The same behavior was observed for other strength and fracture toughness ratios.

From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack growth behavior for three crack lengths oriented at 45 deg based on the ratio of the bone to cement line fracture properties. Gnc-b/Gnc-cl denotes the ratio of Mode I (opening) fracture toughness of bone to cement line and σnc-b/σnc-cl denotes the ratio of the tensile strength of bone to cement line. The strength and toughness ratios were obtained by keeping the interstitial bone and osteon properties constant (Table ) while varying the cement line properties. The ranges of cement line properties used to obtain these ratios are marked on the graphs. Note that the values reported in the figures denote the amount of crack extension. The trendline represents the average of the deflection and penetration data sets.

From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack growth behavior for 45 deg crack with two different osteon properties. The model with Osteon 1 has the same cohesive properties for both the osteonal and interstitial bones. In the second model, the osteon (Osteon 2) has 40% lower strength and 40% higher toughness than the interstitial bone. Gnc-b/Gnc-cl denotes the ratio of Mode I (opening) fracture toughness of bone to cement line and σnc-b/σnc-cl denotes the ratio of the tensile strength of bone to cement line. The strength and toughness ratios were obtained by keeping the interstitial bone properties constant (Table ) while varying the cement line properties. The ranges of cement line properties used to obtain these ratios are marked on the graphs. The trendline represents the average of the deflection and penetration data sets.

From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack growth behavior for 45 deg and 90 deg crack orientations based on the ratio of the bone to cement line normal fracture properties. Gnc-b/Gnc-cl denotes the ratio of Mode I (opening) fracture toughness of bone to cement line and σnc-b/σnc-cl denotes the ratio of the tensile strength of bone to cement line. The strength and toughness ratios were obtained by keeping the interstitial bone and osteon properties constant (Table ) while varying the cement line properties. The ranges of cement line properties used to obtain these ratios are marked on the graphs. The solid and hollow circles correspond to individual simulations for penetration and deflection, respectively. The solid lines represent the transition boundary between crack deflection and penetration based on the individual simulation data.

From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack driving force versus crack extension for crack penetration into the osteon and crack deflection into the cement line. Note that the crack is oriented at 45 deg.

From: Finite Element Modeling of Microcrack Growth in Cortical Bone Date of download: 10/8/2017 Copyright © ASME. All rights reserved. From: Finite Element Modeling of Microcrack Growth in Cortical Bone J. Appl. Mech. 2011;78(4):041016-041016-9. doi:10.1115/1.4003754 Figure Legend: Crack driving force versus crack extension for three crack lengths oriented at 45 deg. Note that this plot is for Mode I fracture toughness ratio of Gnc-b/Gnc-cl=1 and tensile strength ratio of σnc-cl/σnc-cl=3.5. The same behavior was observed for other strength and fracture toughness ratios. Note that the crack extension values shown in the figure (182 μm, 253.5 μm, and 532 μm) correspond to initial crack lengths of 425 μm, 353.5 μm, and 75 μm, respectively.