Band 14, Heft 1

The paper focuses on the process of non-contacting kinetic energy accumulation at the dead-end positions of a reciprocating rectilinear motion with a variable stroke. It describes the development of a magnetic-mechanical accumulator that absorbs energy while the moving part is decelerating towards the dead-end position and releases the energy back to the system while it is accelerating from the dead-end position. At the same time, it enables stroke modification of a certain level with a minimal impact on the maximum force of the accumulator. With respect to the magneto-static analysis of components, the preload of the mechanical element has been set accordingly. The dynamic analysis of the system has been carried out and the prototype produced and tested on the testing rig.

This article presents the key elements in understanding the development and design of uniforms for the employees of the Customs Administration of the Republic of Slovenia for the purpose of corporate identity. It will show, in detail, the process from design to analysis of evaluation data for the multifunctional waterproof jacket, after three months of wearing by the employees. The success of a corporate uniform depends on how effectively it serves a specific function, makes the organisation recognisable in society and also on the satisfaction level of the user. The results are presented in four groups: First, the relationship between design and communicating identity for recognition in the market; Second, the determination of the pattern and functionality considerations; Third, the selection of materials and their properties; Last, the quality of workmanship, giving practical value to the above parameters.

Effective thermal conductivity (ETC) is a very important index for evaluating the thermal property of heterogeneous materials, which include more than two different kinds of materials. Several analytical models were proposed for predicting the ETC of heterogeneous materials, but in some cases, these models cannot provide very accurate predictions. In this work, several analytical models and numerical simulations were studied in order to investigate the differences among them. In addition, some factors which would influence the ETC of heterogeneous materials were investigated by numerical simulation. The results demonstrated that the numerical simulation can provide very accurate prediction, indicated that different analytical models should be selected to predict specific problems based on their assumptions, and suggested that more variables need to be considered in order to improve these analytical models, such as inclusion shape, inclusion size, distribution of inclusions and contact area. Besides, numerical method could be an effective and reliable way to obtain the ETC of heterogeneous materials with any kind of complicated structures.

A new method for predicting correlation between fabric parameters and the drape is developed. This method utilises a Principal Component Analysis (PCA) of intercorrelated influencing parameters (bending rigidity, weight, thickness) and the drape parameters (drape coefficient and the node number). This paper describes the PCA procedure and presents the similarities and contrasts between variables.

Numerical simulation tools are increasingly used for developing novel composites and composite reinforcements. The aim of this paper is the application of digital elements for the simulation of the mechanical behaviour of textile reinforcement structures by means of a finite element analysis. The beneficial computational cost of these elements makes them applicable for the use in large models with a solution on near micro-scale. The representation of multifilament yarn models by a large number of element-chains is highly suitable for the analysis of structural and geometrical effects. In this paper, a unit cell generating method for technical reinforcement textiles, using digital elements for the discretization, is introduced.

For the development of a new generation non-crimp fabrics (NCF) made of carbon fibres, a feasibility study of different characterisation methods and surface treatments of the used carbon fibres needs to be performed. In order to join the carbon fibre layers with the binder for realising this new type of NCF, the surface topography and functionality of the fibres have to be analysed first. The wettability of the binder to the carbon fibre surface is of prime significance and needs to be enhanced. Here, the enhancement is carried out by improving the surface energy using atmospheric plasma of compressed air, argon and nitrogen. It is also proposed to improve the surface energy through chemical techniques.

The aim of this study was to investigate the effect of knitting parameters on the moisture management and air permeability of the interlock fabrics. Samples were produced at two different knitting gauges, each with three different stitch lengths. It was found that the fabric mass per square metre increases by increasing machine gauge and decreasing the stitch length, whereas the fabric thickness and porosity increase at these settings. It was further concluded that the loosely knitted fabric samples with higher amount of entrapped air exhibit good air permeability but poor moisture management properties.