10 research outputs found
A new type of Cambrian section at the base of the pre-mesozoic complex of the West Siberian petroleum megabasin (based on Vostok-1 stratigraphic well data, Northern Tomsk Region)
The first section of vendian deposits in the basement complex of the West Siberian petroleum megabasin (resulting from the drilling of the Vostok-3 parametric borehole in the Eastern Tomsk region)
Interregional Correlation of the Permian Continental and Marine Deposits of Northeastern Russia, Southern Far East, Siberia, and Pechora Cisurals
The effect of constitutive representations and structural constituents of ligaments on knee joint mechanics
Abstract Ligaments provide stability to the human knee joint and play an essential role in restraining motion during daily activities. Compression-tension nonlinearity is a well-known characteristic of ligaments. Moreover, simpler material representations without this feature might give reasonable results because ligaments are primarily in tension during loading. However, the biomechanical role of different constitutive representations and their fibril-reinforced poroelastic properties is unknown. A numerical knee model which considers geometric and material nonlinearities of meniscus and cartilages was applied. Five different constitutive models for the ligaments (spring, elastic, hyperelastic, porohyperelastic, and fibril-reinforced porohyperelastic (FRPHE)) were implemented. Knee joint forces for the models with elastic, hyperelastic and porohyperelastic properties showed similar behavior throughout the stance, while the model with FRPHE properties exhibited lower joint forces during the last 50% of the stance phase. The model with ligaments as springs produced the lowest joint forces at this same stance phase. The results also showed that the fibril network contributed substantially to the knee joint forces, while the nonfibrillar matrix and fluid had small effects. Our results indicate that simpler material models of ligaments with similar properties in compression and tension can be used when the loading is directed primarily along the ligament axis in tension