Shape memory polymer (SMP) composites are attractive and excellent smart materials due to their outstanding properties and rich functionality as they combine typical mechanical and functional properties of composites with shape memory properties. In particular, 3D reinforced preforms have tremendous potential for the development of functional composites by using the capabilities of 3D woven fabric preform design, and polymer shape memory behavior. Within that scope, this work aims to investigate the shape memory behavior and shape recovery properties of a specific type of 3D multilayer woven SMP composite in response to external stimuli. For this purpose, nine different multilayer stitched fabrics are produced with different weave structures, and different fabric thread densities using polyimide filaments. Then, a series of tests is carried out on these fabrics to evaluate their mechanical and physical properties. The layered fabric design that delivers high mechanical performance is next involved to manufacture the SMP composite samples, for which shape recovery capability is investigated. Fold-deploy and other shape memory cycle tests are performed to evaluate the shape memory characteristics. An optical 3D scanner based on fringe projection is further proposed to precisely acquire the geometry data and perform deformation analysis to quantitatively evaluate the shape fixity and shape recovery behaviors. The results from this study are very promising, demonstrating that these multilayer SMP structures can successfully be recovered following the desired design constraints without noticeable damage.

This study evaluates the effects of lengths and reinforcement ratio of Raphia vinifera fibres (RVFs) on the physical and mechanical properties of an epoxy matrix composite. Three volume fractions (20, 30, and 40) and three lengths (5, 10, and 15mm) of fibres were used to produce the composite, and the samples were subjected to the absolute and apparent density, porosity, water absorption rate, and tensile and flexural strength. The probability of failure of the composite is described by the means of two-factor Weibull model. In addition, a theoretical approach to predict mechanical characteristics based on empirical models was carried out. The results show that the addition of RVF decreases the density of the composite, while the porosity and absorption rate increase. The mechanical test shows that the tensile and flexural stress and Youngs modulus of the composite are lowered compared to those of the resin alone. Multivariate analysis of variance (MANOVA) and Tukey test showed that fibre lengths and reinforcement ratio significantly lower the mechanical properties of the composite. The distribution of strength and Youngs modulus follows Weibulls law. Furthermore, the CoxKrenkel mathematical model has the best approximated model for the experimental results after the tensile test. Based on these results, this material could be used as reinforcement parts for vehicle backrests or interior decoration in the construction industry.

Cashmere is widely acclaimed as one of the most luxurious textile fibers. Mongolia, a major player in cashmere production and processing, is key to this industry. Despite the rich history of cashmere, there is limited research on cashmere fiber properties, which are essential in producing high-quality garments. This study aims to improve our understanding of cashmere fibers’ physical and mechanical properties and to assess how genetic and non-genetic factors affect these characteristics. We analyzed key fiber characteristics, including scale morphology, and the physical and mechanical properties (such as fineness, length parameters, stress, and strain) in 11 samples from Mongolian goats of varying areas, breeds, ages, and genders. Through detailed statistical analysis, our experimental results revealed that both genetic and non-genetic factors significantly affect fiber fineness and the specific energy of rupture. Additionally, we observed that the influence of these factors can inform better classification systems for raw cashmere and enhance the determination of the fiber’s spinability limit.

The weavability limit and tightness for 2D and 3D woven fabrics is an important factor and depends on many geometric parameters. Based on a comprehensive review of the literature on textile fabric construction and property, and related research on fabric geometry, a study of the weavability limit and tightness relationships of 2D and 3D woven fabrics was undertaken. Experiments were conducted on a representative number of polyester and cotton woven fabrics which have been woven in our workshop, using three machines endowed with different insertion systems (rapier, projectiles and air jet). Afterwards, these woven fabrics have been analyzed in the laboratory to determine their physical and mechanical characteristics using air permeability-meter and KES-F KAWABATA Evaluation System for Fabrics. In this study, the current Booten’s weavability limit and tightness relationships based on Ashenhurst’s, Peirce’s, Love’s, Russell’s, Galuszynskl’s theory and maximum-weavability is reviewed and modified as new relationships to expand their use to general cases (2D and 3D woven fabrics, all fiber materiel, all yarns etc…). The theoretical relationships were examined and found to agree with experimental results. It was concluded that the weavability limit and tightness relationships are useful tools for weavers in predicting whether a proposed fabric construction was weavable and also in predicting and explaining their physical and mechanical properties.