Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USA.
Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104, USA.
J Mech Behav Biomed Mater. 2024 Jul;155:106577. doi: 10.1016/j.jmbbm.2024.106577. Epub 2024 May 11.
The present study simulates the fracture behavior of diabetic cortical bone with high levels of advanced glycation end-products (AGEs) under dynamic loading. We consider that the increased AGEs in diabetic cortical bone degrade the materials heterogeneity of cortical bone through a reduction in critical energy release rates of the microstructural features. To simulate the initiation and propagation of cracks, we implement a phase field fracture framework on 2D models of human tibia cortical microstructure. The simulations show that the mismatch between the fracture properties (e.g., critical energy release rate) of osteons and interstitial tissue due to high AGEs contents can change crack growth trajectories. The results show crack branching in the cortical microstructure under dynamic loading is affected by the mismatches related to AGEs. In addition, we observe cortical features such as osteons and cement lines can prevent multiple cracking under dynamic loading even with changing the mismatches due to high AGEs. Furthermore, under dynamic loading, some toughening mechanisms can be activated and deactivated with different AGEs contents. In conclusion, the current findings present that the combination of the loading type and materials heterogeneity of microstructural features can change the fracture response of diabetic cortical bone and its fragility.
本研究模拟了高水平糖基化终产物(AGEs)存在下的糖尿病皮质骨在动态载荷下的断裂行为。我们认为,糖尿病皮质骨中增加的 AGEs 通过降低微结构特征的临界能量释放率来降低皮质骨的材料异质性。为了模拟裂纹的萌生和扩展,我们在二维人胫骨皮质微结构模型上实现了相场断裂框架。模拟结果表明,由于 AGEs 含量高,骨单位和间质组织的断裂特性(如临界能量释放率)之间的不匹配会改变裂纹的扩展轨迹。结果表明,在动态载荷下,皮质微结构中的裂纹分支受到与 AGEs 相关的不匹配的影响。此外,我们观察到皮质特征,如骨单位和水泥线,即使在由于高 AGEs 而改变不匹配的情况下,也可以防止在动态载荷下发生多重开裂。此外,在动态载荷下,不同的 AGEs 含量可以激活和失活一些增韧机制。总之,目前的研究结果表明,载荷类型和微结构特征的材料异质性的组合可以改变糖尿病皮质骨的断裂响应及其脆性。