Prediction of tensile behavior of compression therapeutic biomedical materials by mesoscale laid-in loop model

Tubular laid-in weft-knitted compression (LWC) therapeutic materials have been extensively applied in medical clinic treatment and daily healthcare management. Limited studies have explored the mechanical mechanisms through the numerical analytical models for the development and performance prediction of laid-in fabrics. This study developed the three-dimensional (3D) finite element (FE) laid-in loop model to simulate and predict the tensile behaviors of LWC materials based on the determination of geometric models and investigation of yarn mechanical properties. Through the constructed FE mesoscale models with various physical-mechanical characteristics of inlay yarn materials, it was found that the ground yarns and inlay yarns played distinct roles in producing tensile stresses under the course and wale direction of stretching strains. These tensile stresses determined the selection of yarn materials for controlling the tension of laid-in knitted fabrics in end applications. Then, the interfacial pressure dosages exerted by LWC materials were quantitively obtained based on the simulated Young's moduli values and modification of Laplace's Law model. The accuracy and acceptability of proposed mechanical laid-in models (mean error: 10.22 %) and pressure prediction models (mean error: 14.70 %) were validated by the comparative studies. The simulation methods and results created a visual tool for dynamically illustrating the tensile behaviors and predicting pressure performances of the elastic therapeutic materials in functional material design of biomedical compression textiles.