PSI - Issue 28

ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceD rect Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 28 (2020) 577–583

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Abstract Finite-element models are used to estimate numerically the distribution of bone mineral density (BMD) as a result of bone remodelling process from the loads applied. However, the effect of initial BMD distribution on trabecular-bone remodelling is still unknown. In this paper, the effect of initial density distributions as an input in the finite-element model on a structural-functional relationship of trabecular bone was investigated. A multi-material model representing a realistic density distribution was used based on the grey-scale value (GV) distribution and compared with a traditional single-material model. Different trabecular morphologies with density distributions were observed for these two material models. Similar character of the occurrence of density (in terms of element and volume fraction) of trabecular bone from a femur head were found, with the same highest number of elements in the density range from 1.25 to 1.35 g/cm3. These results indicate that previous simplified models using single-material properties for trabecular bone may not lead to considerable errors. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: Bone remodelling; Finite-element; Trabecular bone; Bone mineral density; material property distribution 1. Introduction Osteoporosis is a common bone disease accompanied by a long-term bone mineral density loss, increasing the risk of fracture. Osteoporosis-related fractures mostly occur in trabecular-rich areas such as femoral heads and vertebra [1][2]. Trabecular bone plays an important role in load bearing; it continues renewing its properties to adapt the external loading environment [3]. The evolution of material properties affects elastic properties and density of trabecular bone; however, they are not directly measurable in-vivo [4]. Therefore, finite-element (FE) models are 1st Virtual European Conference on Fracture Trabecular bone remodelling: finite-element simulation Juan Du a,b *, Simin Li b , Vadim V. Silberschmidt b a Academy of Medical Engineering and Translational Medicine, Tianjin University 300072, Tianjin, China b Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University LE11 3TU, Leicestershire, UK Abstract Finite-element models are used to estimate numerically the distribution of bone mineral density (BMD) as a result of bone remod lling process from the loads applied. However, the eff ct of initial BMD distribution on trabecular-bone remodel ing is still unknown. In this paper, the ffect of initial density dis ributions as an input in the finite-element model on a st uctural-functiona relati nship of trabecular bone was investigat d. A multi-material model representing a r alistic density distribu ion was used based on the grey-scale val e (GV) distribution and compared with a traditional singl -material model. Different a ecular morphologi s wit density distributions were observed for these two material models. Similar character of the occurre ce of density (in terms of element and volume fraction) of trabecular bone from a femur hea were found, with the sam highest umber of elements in the density r ge fro 1.25 to 1.35 g/cm3. These r sults indicate t at previous simplif ed models using single-material properties for trabecular bone ay not lead to considerable e rors. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der responsibility of European Structural Integri y So i ty (ESIS) ExC Keywords: Bone remodelling; Finite-element; Trabecular bone; Bone mineral density; material property distribution 1. Introduction Osteoporosis is a common bone disease accompanied by a long-term bone mineral density loss, increasing the risk of fracture. O teopor sis-related fractures mostly occur in trabecula -rich areas such as femoral heads and vertebra [1][2]. T abecular bone plays an impo tant role in load bearing; it continu s renewing its propertie to adap the external loading environment [3]. The evolution of material properties affects lastic pro erti s and density of trabecu ar bone; however, they are not directly measur ble in-vivo [4]. Therefor , finite-element (FE) models are 1st Virtual European Conference on Fracture Trabecular bone remodelling: finite-element simulation Juan Du a,b *, Simin Li b , Vadim V. Silberschmidt b a Academy of Medical Engineering and Translational Medicine, Tianjin University 300072, Tianjin, China b Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University LE11 3TU, Leicestershire, UK

* Corresponding author. Tel.: +86-022-83612122; fax: +86-022-83612122. E-mail address: J_du@tju.edu.cn * Corresponding author. Tel.: +86-022-83612122; fax: +86-022-83612122. E-mail address: J_du@tju.edu.cn

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.10.067