3D连续蚕丝增强仿生半月板的有限元建模及界面强韧化机制研究

Finite Element Modeling and Interfacial Toughening Mechanisms of 3D Continuous Silk-Reinforced Biomimetic Meniscus

  • 摘要: 半月板在膝关节中发挥缓冲减震、维持关节稳定性等重要功能,但临床仍缺少安全有效的半月板植入体。天然半月板组织由取向胶原纤维与糖胺聚糖基质构成,体现“纤维增强复合材料”的结构特征。本文从结构仿生原理出发,基于3D打印连续纤维增强树脂基复合材料设计了半月板植入体,并构建了有限元模型,以纯聚己内酯(PCL)与蚕丝-PCL复合材料为例,评估了植入体的宏观极限承载能力,进而深入分析了纤维-基体的界面剪切强度(IFSS)对植入体模型损伤及失效行为的影响规律。仿真结果表明:在植入体高应力区引入连续纤维能够显著缓解基体内部应力集中,提升植入体在极限载荷下的结构稳定性;在强界面结合(IFSS=60 MPa)条件下,复合材料植入体的竖直压缩模量与周向拉伸模量分别达到14.96 MPa和20.00 MPa,较纯基体模型分别提升了6.3倍与2.9倍。同时,强界面剪切约束能确保纤维载荷分担率维持在80%以上。而弱界面(IFSS=3.77 MPa)因过早脱粘导致载荷传递受阻,将使基体发生过早屈服。通过研究不同IFSS下模型的失效演化过程,确定了15 - 25 MPa为该体系的最佳界面强度区间。在此区间内,模型中“纤维-界面-基体”三组分协同承载,有效兼顾了结构承载强度与断裂韧性。本研究验证了蚕丝增强聚己内酯作为半月板植入体材料的可行性,并揭示了异质界面结合强度在调控纤维增强复合材料及结构力学行为中的关键作用,为高性能半月板植入体的开发提供理论依据。

     

    Abstract: The meniscus plays a critical role in shock absorption and joint stabilization in the knee; however, safe and effective meniscal implants remain clinically unavailable. Native meniscal tissue is composed of circumferentially aligned collagen fibers embedded in a glycosaminoglycan-rich matrix, exhibiting the characteristic architecture of a fiber-reinforced composite. Based on structural biomimetic principles, a meniscus implant was designed using 3D-printed continuous fiber-reinforced polymer composites, and corresponding finite element models were established. Using pure polycaprolactone (PCL) and silk fiber–reinforced PCL composites as representative materials, the macroscopic ultimate load-bearing capacity of the implants was evaluated, followed by an in-depth analysis of the impact of fiber–matrix interfacial shear strength (IFSS) on damage initiation and failure evolution. Simulation results indicate that introducing continuous silk fibers into high-stress regions of the implant significantly reduces stress concentration within the PCL matrix, thereby enhancing structur IFSS al stability under ultimate loading. Under strong interface bonding (IFSS = 60 MPa), the vertical compressive modulus and circumferential tensile modulus of the implant reached 14.96 MPa and 20.00 MPa, respectively, representing 6.3-fold and 2.9-fold improvements over the PCL model. Interfacial performance is a critical factor governing reinforcement efficiency. Strong interfacial shear constraints ensure fiber load sharing exceeds 80%, effectively relieving matrix stress concentration. Conversely, weak interfaces (IFSS = 3.77 MPa) cause premature debonding that impedes load transfer, resulting in accelerated matrix yielding. By comparing failure evolution under different IFSS values, the optimal interface strength range for this system was determined to be 15 – 25 MPa. Within this range, the “fiber-interface-matrix” tripartite system achieves synergistic load-bearing, effectively balancing structural strength and fracture toughness. This study validates the feasibility of silk-reinforced polycaprolactone as a meniscus implant material and elucidates the critical role of interface engineering in continuous fiber-reinforced polyester composites, providing a theoretical basis for developing high-performance meniscus implants.

     

/

返回文章
返回