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Modelling and Testing of the Properties of Recovered Composite Material
Abstract
The main goal of the current study is to develop new composite material from recovered composite plastic powder to have higher filler content in polyester resin matrix. The new composite is modelled on basis of the properties of new material. Such an approach requires tests of the new material. The considered target characteristics of the new material are the tensile strength, surface hardness and the cost. The multicriteria optimization problem has been formulated and solved by use of physical programming techniques and Pareto optimality concept. The designed new composites were manufactured in different mixing ratios of powder and binder agent. The strength and stiffness properties of new composite material were tested.
... This approach is also a response to the search for new types of composites and materials better adapted to new technologies. Aspects of their preparation remain a topical issue in the field of new types of nanocomposites, and actual challenges include obtaining desirable or unique properties, controlling their fabrication procedures, and ensuring the compatibility of their different components [7][8][9]. Polysaccharides perform many important functions in nature, from acting as cell-building materials to storing cellular energy, which are performed as a result of internal metabolic cycles [10][11][12]. As a result of the differences in the structure of the units as well as the branching of the polymer chain, they differ in their physicochemical properties. ...
A series of new types of composites (biopolymer-silica materials) are proposed as selective and effective adsorbents. A new procedure for the synthesis of chitosan-nanosilica composites (ChNS) and chitosan-silica gel composites (ChSG) using geometrical modification of silica and mechanosorption of chitosan is applied. The highest adsorption efficiency was achieved at pH = 2, hence the desirability of modifications aimed at stabilizing chitosan in such conditions. The amount of chitosan in the synthesis grew to 1.8 times the adsorption capacity for the nanosilica-supported materials and 1.6 times for the silica gel-based composites. The adsorption kinetics of anionic dyes (acid red AR88) was faster for ChNS than for ChSG, which results from a silica-type effect. The various structural, textural, and physicochemical aspects of the chitosan-silica adsorbents were analyzed via small-angle X-ray scattering, scanning electron microscopy, low-temperature gas (nitro-gen) adsorption, and potentiometric titration, as well as their adsorption effectiveness towards selected dyes. This indicates the synergistic effect of the presence of dye-binding groups of the chi-tosan component, and the developed interfacial surface of the silica component in composites.
Aim of the current study is to design the extra frontal protection system of
a car satisfying the requirements of directive 2005/66/EC of the European
Parliament and of the Council. The car frontal protection system is treated
as additional energy absorbing element. An analysis of a car-pedestrian
crash situation is performed by use of explicit Finite Element Analysis
solver and the following stiffness analysis with implicit Finite Element
Analysis solver. For modeling response surface and search for optimal
solution the LS-OPT software is utilized and some comparative simulations
are performed by use of MATLAB. The experimental validation of the models
designed is performed.
This paper deals with the parametric identification of a small-scale bridge
model that was intended to approximately reproduce the transversal dynamic
behaviour of its corresponding prototype. This is representative of a
typical multi-span continuous-deck irregular bridge. A linear model with
viscous damping is proposed to reproduce its dynamic response. The
identification is carried out in the time domain using experimental
earthquake-induced data and assuming the mass is known. An identification
procedure including a genetic algorithm with parallel selection has been
developed. In the studied case, the procedure has demonstrated to be robust.
It is shown that the model could be improved by using a non linear approach
for the dissipative forces.
Fillers are widely used in thermosets, thermoplastics and elastomers. Current estimates put the global market for fillers at between 12 and 18 million tonnes per year. Originally, their main function was seen as reducing the cost of the compound. However, in recent years it has become more widely recognized that fillers can enhance the processability and mechanical properties of compounds. The term functional fillers is now used to emphasize the positive benefits achieved through the addition of fillers. Even in cases where fillers are added primarily to reduce cost, they still alter the properties of the compound and it is therefore important to understand the changes that fillers bring about. Dr. Chris DeArmitt and Professor Roger Rothon describe the key filler characteristics that influence the manufacture and final properties of compounds - illustrated with specific examples for common fillers. In addition, they cover the use of surface treatments for fillers and how the judicious use of surface treatment additives can further enhance filled plastic compounds.
The multi-functional DS-series disintegrators have been utilized for reprocessing of the glass fibre reinforced plastic (GFRP) scrap. The technology of milling by the disintegrator devices is compared with the existing advanced technologies and the advantages of disintegrator milling are pointed out. Preceding from the results of size, shape and properties analysis of the milled powder particles the numerical algorithm for modelling of the density of the polymethylmetacrylate (PMMA) powder is developed. Multicriteria optimisation problem has been formulated and solved by employing Pareto optimality concept and physical programming techniques.
Fibres are used for a large variety of applications. Textiles, nonwovens as well as fibre reinforced composite materials are commonly used in daily life and in technical applications. The annual world fibre market amounts to about 60 million t including natural and man-made fibres. Due to increased ecological awareness and more severe legislations disposal of waste is increasingly avoided through the use of recycling technologies. This development also takes place in the field of fibre materials. However, proper processes for fibre recycling are not yet fully developed. Commonly end-of-life fibres are supplied for energetic utilization. This method is not favourable since the energy generated from burning is much lower than the energy required for fibre manufacturing. The paper presents the state-of-theart in recycling fibres. Available technologies for textiles, carpets, composites and end-oflife vehicles are reviewed. However, these technologies do not offer satisfying solutions in terms of economic and ecologic demands. Within this study product recycling of fibres obtained from tyres is investigated. It is demonstrated that fibres recycled from waste tyres can be converted from waste to a valuable raw material if processed properly. Characterization possibilities for recycled fibres are also presented. It is demonstrated that most methods cannot provide feasible results. In the course of this research project a system based on optical image processing has been adopted for the characterization of recycled fibres. Characterization is necessary for product and quality control. Lastly, an adequate application for the recycled fibre materials is evaluated in this study. By addition of fibres gained from waste tyres an improvement of bitumen properties was found. An economic benefit can be expected since recycled fibres can substitute expensive state-of-the-art solutions.
As high-speed networks have proliferated across the globe, their topologies have become sparser due to the increased reliability of components and cost considerations. Reliability has been a traditional goal within network design optimization. An alternative design consideration, network resilience, has not been studied or incorporated into network designs nearly as much. The authors propose a methodology for the difficult estimation of traffic efficiency (TE), a measure of network resilience, and a hybrid genetic algorithm to design networks using this measure.
The weighting summation decision method is commonly used and misused for multiobjective decisions. The formal requirements of this method are outlined and some of the kinds of errors that are commonly made in applying it are discussed. Monte Carlo simulation is used to assess the potential that five classes of errors have for causing incorrect decisions. An index is developed which quantifies the complexity of decision problems. The simulations demonstrate that complexity can be about twice as important to quality of decisions as are errors in applying the weighting summation.