No abstract

Three-dimensionally (3D) knitted technology textiles are expanding into industrial and technical applications of textile composites given their geometric, structural, and functional performance. However, there are many challenges in developing computational tools that allow for physics-based predictions while keeping the related computing cost low. The strong interactions between geometrical and physical elements permit determining the behavior of this type of engineering material. In the aim of understanding the specific mechanical behaviors of knitted textiles, a yarn-level simulation model framework was created to predict the nonlinear orthotropic mechanical behavior of monofilament jersey-knitted textiles. The relative contributions of many computational parameters on the global mechanical behavior of knitted fabrics are investigated, specifically, inter-yarn interactions and the boundary conditions effect. The models are saved in a format that can be read directly by Finite Element Analysis FEA software. Yarns are numerically discretized as nonlinear 3D beam components, while input parameters, such as mechanical characteristics of yarns and geometric dimensions of loops in fabrics are established experimentally. Good agreement was relieved by comparing experimental data to simulation results in a wale-wise direction tensile load.

The main aim of this work is to investigate the effect of Alfa fiber length and quantities on linear shrinkage, mechanical strength, and failure manner of the reinforced material as compared to the unreinforced mix, by the incorporation of Alfa fibers in earth-sand building material. The earth-based composite consisted of a mixture of earth 60 wt% and sand 40 wt% reinforced with various lengths and rates of fibers extracted from the Alfa plant. First, fibers' tensile strength and water absorption were evaluated to understand their behavior. Moreover, tests have been conducted on prismatic specimens 40x40x160 mm3 with different cutting lengths (1, 2, and 3 cm). These fibers were added to soil at various weight ratios (1%, 1.5%, and 2%). The results have indicated that the incorporation of 2%wt of fibers reduced the unit weight from 1849 kg/m3 to 1632 kg/m3, which results in a slight material. The experimental investigation has shown also that the unreinforced adobe specimens had a high linear shrinkage rate and low mechanical behavior compared to fibrous samples. Specially, specimens with a higher fiber content of 2%wt of 3 cm length were revealed to be the most suitable in terms of mechanical behavior. Moreover, fibers prevent and delay crack propagation, where fiber length and content play a principal role in crack attenuating. Despite the improvement of mechanical properties, the microstructural observation of the reinforced composite shows poor fiber/matrix adhesion, which affects negatively the compactness of the adobe specimens.