论文部分内容阅读
目的通过有限元数值计算的方法研究年龄变化对牙本质断裂力学行为的影响。方法根据典型的紧凑拉伸试件形式建立有限元模型,采用内聚力模型分别模拟裂纹在年轻和老龄牙本质中稳态扩展的过程,并进行比较。结果老龄牙本质的扩展断裂韧度和断裂韧度趋于恒定时的值分别为0.51、1.19 MPa.m1/2,显著小于年轻牙本质的相应值(7.48、1.71 MPa.m1/2);然而,这两者之间的初始断裂韧度相差比较微小,年轻和老龄牙本质的初始断裂韧度分别为0.51和0.38 MPa.m1/2。结论随着年龄的增长,牙本质抵抗裂纹扩展的能力发生了明显的减弱。基于内聚力模型的数值方法能够很好地预测牙本质等力学性能与年龄相关的生物硬组织材料的裂纹扩展行为。
Objective To study the effect of age on the fracture mechanics of dentin by means of finite element method. Methods The finite element model was established according to the typical compact tensile specimens. The cohesion model was used to simulate the steady-state propagation of the crack in young and aged dentin, respectively, and compared. Results The values of extended fracture toughness and fracture toughness tended to be constant at 0.51 and 1.19 MPa.m1 / 2, respectively, which were significantly lower than those of young dentin (7.48 and 1.71 MPa.m1 / 2). However, , The initial fracture toughness between the two is relatively small, the initial fracture toughness of young and old dentin were 0.51 and 0.38 MPa.m1 / 2. Conclusion With age, dentin resistance to crack growth significantly weakened. The numerical method based on the cohesion model can predict well the crack propagation behavior of age-related biomacromolecules such as dentin and other mechanical properties.