Narrow Results

In this paper, the tangential zone of cartilage is introduced into the fiber-reinforced model of articular cartilage. Considering the distribution content of the main fiber and the secondary fiber in the tangential layer of cartilage, the permeability and fiber stiffness of the layer are set in parallel and perpendicular directions, respectively, to more accurately reflect the mechanical behavior of cartilage. The parameters are set to reflect the mechanical behavior of the cartilage more realistically. We use a modified articular cartilage model to simulate the mechanical properties of implanted cartilage with different elastic modulus. The simulation results show that the selection of implants with different elastic modulus will affect the repair of cartilage. Appropriately increasing the elastic modulus of implanted cartilage, can increase the bearing capacity of the repaired area and reduce the stress concentration at the junction. The elastic modulus of the implant should be moderate, not too large or too small, and the damage of stress concentration on the repair surface should be considered. Through simulation, the mechanical state of the repaired cartilage under pressure can be obtained comprehensively, which provides a theoretical basis for clinical pathology.

Steel fiber-reinforced self-compacting concrete (SCFRC) has been developed in recent decades to overcome the weak tensile performance of traditional concretes. As the flexural strength of SCFRC is dependent on the distribution of steel fibers, a numerical model based on Jeffery’s equation was developed in this study for investigating the effects of the concrete flow on the fiber orientation and distribution in SCFRC. This numerical method shows higher computational efficiency than available particle-based methods like SPH and LBM. The influence of casting parameters like casting method, formwork size and casting velocity on the fiber orientation is investigated from the perspective of the flow field of fresh concrete during casting. The simulation results show that the fiber orientation is largely dominated by the concrete flow during the casting process. Importantly, during casting SCFRC beam, fibers tend to be oriented in parallel along the longitudinal direction at the middle section, while they stick up at the end of the formwork due to the upward concrete flow. In addition, the results from parametric studies show that the formwork size and casting method could significantly affect the concrete flow during the casting process, ultimately the orientation of fibers in a SCFRC beam. Furthermore, it indicates that the casting speed needs to be carefully chosen in order to achieve the optimal fiber alignment.