Evaluation of impact behaviour of composite materials using Taguchi method

Impact behaviour is a major target in designing advanced composite materials because composites are often used in applications which imply dynamic loads. Composite materials reinforced with 3D knitted fabrics present a wide range of applications in the technical field. Their main advantages refer to excellent formability, controlled anisotropy and good mass/strength ratio. The paper considers advanced composite materials reinforced with sandwich fabrics with various cell sizes, made of Kevlar, Twaron and linen yarns, and thermoset matrix. Low velocity impact behaviour of composite materials reinforced with 3D weft knitted fabrics is modelled using the Taguchi method based on orthogonal arrays, in order to maximize the composite characteristics significant for this type of impact. The results obtained through Taguchi analysis are validated by experimental data

Modeling and Simulation of Human Body Heat Transfer System Based on Air Space Values in 3D Clothing Model

Comfort can be considered as subjective feeling, which could be affected by the external ambient, by the physical activity, and by clothing. Considering the human body heat transfer system, it mainly depends on various parameters including clothing materials, external and internal environment, etc. The purpose of the current paper is to study and establish a quantitative relationship between one of the clothing parameters, ease allowance (air gap values) and the heat transfer through the human body to clothing materials and then to the environment. The study considered clothing which is integrated with the 3D ease allowance from the anthropometric and morphological data. Such incorporating of the clothing’s 3D ease control was essential to properly manage the air space between the body and the proposed clothing thermal regulation model. In the context of thermal comfort, a clothing system consisting of the human body, an ease allowance under clothing, a layer of textile materials, and a peripheral layer adjacent to the textile material was used. For the complete system, the heat transfer from the skin to the environment, which is influenced by thermoregulation of the human body, air gap, tissue, and environmental conditions were also considered. To model and predict the heat transfer between the human body and the temperature of skin and clothes, a 3D adaptive garment which could be adjusted with ease allowance was used. In the paper, a thermoregulatory model was developed and proposed to predict the temperature and heat within clothing material, skin, and air space. Based on the result, in general the main difference in the temperature of clothing and skin from segment to segment is due to the uneven distribution of air layers under the clothing

A New Approach to Dynamic Anthropometry for the Ergonomic Design of a Fashionable Personalised Garment

Background: A challenge for designers is to create fashionable and very well-fitting personalised garments (multi-layered) that have a suitable shape (balance and size) and provide the wearer with the desired degree of freedom. In this paper, the authors have developed an ergonomic solution for designing the pattern of a business casual men’s jacket by integrating the dynamic data of the body into the design process. Methodology: The pattern was elaborated by interactive design process based on mathematical relationships and the use of specific input data. The 3D virtual prototype was created in Clo3D (the static and typical dynamic positions of the mannequin). The dynamic data needed for the study were measured directly on 50 male subjects. These values were analysed by using the statistical method and then integrated into the design scenario in a specific way. The shapes of the new 3D prototypes were evaluated by examining the relationships between the constructive and longitudinal allowance along the back region as independent variables and sleeve angle and upper back tension as dependent variables. Results: By allowing a certain degree of dynamic effect in the design process, one can see that the personalized model of the casual business jacket with Ab (constructive allowance) = 4.5 cm and Aars (longitudinal allowance distributed along with the back height) = 3.6 cm is well balanced and fits the body. Conclusions: This design method can be used and further developed for other garment categories and customers by any design department that has the right IT tools to facilitate the personalized design process

FEM Analysis of Textile Reinforced Composite Materials Impact Behavior

Composite materials reinforced with textile fabrics represent a complex subject. When explaining these materials, one must consider their mechanical behavior in general, and impact resistance in particular, as many applications are characterized by dynamic strains. Impact characteristics must be considered from the early stages of the design process in order to be controlled through structure, layer deposition and direction. Reinforcement materials are essential for the quality and behavior of composites, and textile reinforcements present a large range of advantages. It takes a good understanding of the requirements specific to an application to accurately design textile reinforcements. Currently, simulations of textile reinforcements and composites are efficient tools to forecast their behavior during both processing and use. The paper presents the steps that must be followed for modelling the impact behavior of composite materials, using finite element analysis (FEM). The FEM model built using Deform 3D software offers information concerning the behavior structure during impact. The behavior can be visualized for the structure as a whole and, for different sections, be considered significant. Furthermore, the structure’s strain can be visualized at any moment. In real impact tests, this is not possible due to the very short time interval and the impossibility to record inside the structure, as well as to record all significant stages using conventional means

New Waste-Based Composite Material for Construction Applications

The global demand for fiber-based products is continuously increasing. The increased consumption and fast fashion current in the global clothing market generate a significant quantity of pre-and post-production waste that ends up in landfills and incinerators. The present study aims to obtain a new waste-based composite material panel for construction applications with improved mechanical properties that can replace traditional wood-based oriented strand boards (OSB). The new composite material is formed by using textile wastes as a reinforcement structure and a combination of bi-oriented polypropylene films (BOPP) waste, polypropylene non-woven materials (TNT) waste and virgin polypropylene fibers (PP) as a matrix. The mechanical properties of waste-based composite materials are modeled using the Taguchi method based on orthogonal arrays to maximize the composite characteristics’ mechanical properties. Experimental data validated the theoretical results obtained