Wydawnictwa Uczelniane / TUL Press
Stały URI zbioruhttp://hdl.handle.net/11652/17
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Pozycja Development of sensor design for smart kinesiotape for future sensing applications in motion capturing(Wydawnictwo Politechniki Łódzkiej, 2022) Winger, Hans; Böhnke, Philippa Ruth Christine; Kruppke, Iris; Nocke, Andreas; Cherif, ChokriThe “CENTRE FOR TACTILE INTERNET WITH HUMAN-IN-THE-LOOP (CeTI)” is a Cluster of Exellence that, from an textile point of view, deals with the development and invention concerning smart devices [1]. These can be used in many fields e.g. industry 4.0, medicine and skill leaning. Currently expensive, tender and large, stationary camera systems are necessary to capture human motions for various applications. The usage of textile substrates with implemented sensory units gives high potential for body-near motion capturing. Smart textiles gain more and more interest in the field of sports [2] and health monitoring. The avoidance of personal injuries due to the incorrect execution of movements is one main target to reach with smart textiles in healthcare and sports. The aim of the contribution is the investigation of characteristics using electrically conductive (EC) yarns implemented in woven textiles as future smart textiles for close up motion capturing.Pozycja Simulation based development of profiled carbon rovings for concrete reinforcements(Wydawnictwo Politechniki Łódzkiej, 2022) Penzel, Paul; Seidel, Jakob; Lang, Tobias Georg; Hahn, Lars; Cherif, Chokri; Mechtcherine, ViktorTextile reinforcements are increasingly establishing their position in the building industry due to their high tensile properties and corrosion resistance. However, in contrast to ribbed monolithic steel bars with a defined form fit effect, the bond force of conventional carbon rovings are transmitted primarily by an adhesive bond (material fit) between the textile surface and the surrounding concrete matrix. Hence, relatively large bonding lengths are needed to transmit the bond forces, which results in an inefficient material utilization. New solutions involving tetrahedral profiled rovings and braided yarns promise significant improvements in the bonding behavior of textile reinforcements by creating an additional mechanical interlock with the concrete matrix, yet maintaining the high tensile properties of the carbon fibers. In order to increase the transmittable bond force and bond stiffness of the profiled rovings through a defined roving geometry, a simulation-based development was conducted. Hereby geometry and material models were developed and tensile tests as well as pull-out tests were simulated. The results of simulation and characterization enable the optimization of the geometry parameters of the tetrahedral profiled rovings and braided yarns to achieve better bond and tensile properties.Pozycja Flowable 2D textile structures for the production of thermoplastic 3D FRP parts with continuous fiber reinforcement between shell and rib(Wydawnictwo Politechniki Łódzkiej, 2022) Hellmann, Sven; Overberg, Matthias; Pham, Minh Quang; Häntzsche, Eric; Gereke, Thomas; Cherif, ChokriNature shows evolutionary fiber-reinforced solutions, e.g. a peanut shell that enables a high stiffness with extremely low component masses by using complex shell and rib arrangements. Lightweight shellshaped components made of fiber-reinforced plastic (FRP) are often stiffened with ribs. In this work, a new method is proposed to produce directional fiber reinforcement in the transition area from shell to rib and within the rib by a direct thermal pressing process. Numerical calculations are initially used to demonstrate the potential of this type of structure. The source material is a flowable 2D textile hybrid structure consisting of continuous glass fibers and discontinuous recycled carbon fibers. The arrangement of the fibers leads to a defined flow movement of matrix and fibers and thus the production of a 3D FRP component with continuous fibers in the shell area and staple fiber-based reinforcement in the rib area and in between.Pozycja Development of integrated in-Situ actuator networks for the realization of flexure hinges for highly deformable fiber-reinforced plastic composites(Wydawnictwo Politechniki Łódzkiej, 2022) Bollengier, Quentin; Rabe, David; Mersch, Johannes; Häntzsche, Eric; Nocke, Andreas; Cherif, ChokriIn the course of promoting e-mobility, there is currently a high demand for functionalized fiberreinforced plastics (FRPs). In particular, adaptive FRPs with structurally integrated actuators have a high innovation potential, since conventional motion mechanisms are usually based on external kinematics with high energy consumption. Even though actuators based on shape memory alloy (SMA) can be easily processed by mean of textile techniques, only few studies use the weft-knitting technology for the realization of adaptive FRPs with integrated actuator networks. This study aims at the development of functionalized weft-knitted fabrics with integrated in-situ actuator networks for the realization of adaptive FRPs. Therefore, functionalized reinforcement fabrics with integrated SMA actuators were developed and produced by weft knitting. The production of the composite infused by means of a thermosetting resin system. Afterward, the functional properties of adaptive FRPs were characterized and evaluated. In summary, this study highlights the suitability of the weft-knitting technology for the integral manufacturing of functionalized reinforcement fabrics with integrated in-situ actuator networks for the realization of adaptive FRP composites.Pozycja Innovative thermally stablized low twist hybrid yarns from recycled carbon fibre for thermosplastic composites(Wydawnictwo Politechniki Łódzkiej, 2022) Hasan, Mir Mohammad Badrul; Khurshid, Muhammad Furqan; Abdkader, Anwar; Cherif, ChokriHybrid yarns consisting of rCF and thermoplastic fibre offer a good potentials to improve mechanical properties of carbon fibre reinforced composites due to high fiber length, homogeneous mixing and high rCF content [1]. However, the twisting of the yarn in conventional spinning processes leads on one hand to the damage in rCF during spinning because of its high brittleness and sensitivity to shear forces. On the other hand, mechanical properties e.g. tensile and flexural strengths of composites decrease significantly with the increase of twist as a result of low fibre orientation [2]. On the contrary, the yarn strength and the stability of the spinning process are strongly dependent on the level of yarn twist. In our previous paper [3], the development of low twist hybrid yarns (75-30 T/m) consisting of rCF and polyamide 6 (PA6) fibre for high performance thermoplastic composites has been reported. However, hybrid yarns with low twist levels suffer from low spinning stability and poor yarn strength, which limits their further processablity in weaving or knitting processes. Therefore, the focus of this work is the development of a method to reduce yarn twist but still ensuring a stable spinning process, high yarn and composite strengths.Pozycja Micromechanical models for fabrics and composites made of hybrid yarns from recycled carbon fibers(Wydawnictwo Politechniki Łódzkiej, 2022) Lang, Tobias; Hasan, Mir Mohammad Badrul; Huynh, Thy Anh My; Gereke, Thomas; Abdkader, Anwar; Cherif, ChokriAlthough the great potential of carbon fibers for use in lightweight applications has been demonstrated in the past, their cost and environmental impact remain a barrier to their widespread use [1]. Recycling of carbon fibers from end-of-life components and combining them with thermoplastic fibers to form hybrid yarns addresses both issues. Due to the stochastic nature of hybrid yarns in terms of recycled carbon fiber (rCF) length and orientation [2], their influence on drapability and performance of rCF composites needs to be investigated. In this paper, a micromechanical model for analysing the dry and composite properties of yarns made from rCF is presented. By using a self-developed framework for generating representative volume elements (RVE) based on parameters such as fiber length, orientation, waviness, and fiber volume content, a variety of idealised random yarn geometries is created. A subsequent simulation step of the compaction of the RVE assures a more realistic RVE geometry. The models are validated by carrying out virtual tests and comparing the results with real tensile tests. The modelling approach can be used for further analyses.Pozycja Non-stationary effects of ring rail movement in the high-speed ring spinning process with a superconducting magnetic bearing twisting system: problem and its solution(Wydawnictwo Politechniki Łódzkiej, 2022) Hossain, Mahmud; Abdkader, Anwar; Cherif, Chokri; Sparing, Maria; Hühne, Ruben; Maximilian, Krentzien; Beitelschmidt, MichaelCurrently, a major challenge in conventional ring spinning is to increase productivity. This is essentially due to friction between the twisting elements. An innovative approach to the solution is the use of frictionless twisting system based on superconducting magnetic bearing (SMB) system. However, previous studies with the SMB system were mainly restricted to an angular spindle speed of up to 30.000 rpm because of: instabilities caused by the non-stationary process forces originating from the nonuniform ring rail movement, complex interactions between the yarn dynamics and the bearing properties of the SMB, aerodynamical subsonic flow regimes of the rotating yarn balloon etc. The ring-rail movement must be taken into account especially at higher angular spindle speed, as a ring-rail cycle occurs every few rotations of the spindle and results in fast-periodic variation of the balloon form, which in turn leads to extreme yarn tension peaks. In this study, metrological investigations were conducted considering the ring rail movement at different angular spindle speeds with the SMB twisting system to understand the influence of the ring rail movement on the spinning stability, dynamic yarn path during spinning process, balloon form etc. Moreover, a concept using servo motor driven lifting mechanism is presented to solve the problem of non-uniform ring rail movement.Pozycja Experimental and numerical evaluation of force transduced by interactive fiber rubber composite structures(Wydawnictwo Politechniki Łódzkiej, 2022) Annadata, Achyuth Ram; Lohse, Felix; Gereke, Thomas; Cherif, ChokriShape memory alloys (SMA) represent a category of smart materials and are widely used as actuators for many applications ranging from aircraft-automotive as vibration dampers to medical stents mainly because of their high energy density and their ability to generate high actuating forces. One of the potential applications of use of SMA is in robotics. SMA integrated composites provide a light-weight solution for conventional grippers but have their fair share of disadvantages such as minimal movements due to constrained degrees of freedom, less gripping force towards irregular structures, durability reduction etc. In this work, SMAs are integrated into glass fiber reinforced fabrics with tailored properties with the help of flat-knitting technology creating an Interactive Fiber Rubber Composite by infiltrating the fabrics with liquid silicone. To determine the range of force induced, a simulation model is developed to capture the transduced force of the composite when SMA is activated and the model is calibrated with respect to a test set-up specifically tailored to determine the force exhibited. The results obtained are utilized in a future study in determining the twisting behaviour of the composite, which would further help in a better grip for small and irregular shaped objects.Pozycja In-situ stress analysis of fiber reinforced plastics under bending load until failure by using integrated textile-based piezoresistive sensors(Wydawnictwo Politechniki Łódzkiej, 2022) Xuan, Hung Le; Nocke, Andreas; Cherif, ChokriThe application of fiber reinforced composites (FRC) for load-bearing and safety-relevant components requires regular inspections to assess the structural conditions. A suitable solution are integrated textilebased piezoresisitive sensors for structural health monitoring applications. This research work focusses on the evaluation and comparison of the electromechanical strain sensing behaviour of steel wires and carbon fibers on the fiber and composite scale. The electromechanical properties are investigated by using a uniaxial fiber tensile test with a simultaneous electrical resistance measurement. Glass fiber reinforced plastic (GFRP) specimen with in-situ sensors are tested in quasistatic and cyclic three-point bending tests. The acquired sensor signals are used for a comprehensive stress analysis and better understanding of the failure behaviour. The cyclic testing procedure showed reproducible sensor signals.Pozycja Analysis of the local yarn elongation states during the highly dynamic stitch formation process using the example of high performance warp knitting(Wydawnictwo Politechniki Łódzkiej, 2022) Bruns, Mathis; Nocke, Andreas; Golla, Anke; Cherif, ChokriMost textile processing methods are dominated by highly inconstant and dynamic thread demands. In terms of increasing production speeds in textile industry or the effort not to influence the fabric appearance by machine stops etc., an effective control and parameterization of the machine is indispensable. This requires precise knowledge of the actual condition of the thread during processing. The state of the warp yarn sheet depends, for example, on the current yarn tension or elongation. While the yarn tension can be easily measured with mobile yarn tension meters, the actual elongation of the yarns is more difficult to observe in the highly dynamic process. Since high-speed warp knitting is one of the most dynamic textile production processes, an observation of the actual elongation states of the yarns to be processed during warp knitting is performed using highspeed optical image acquisition and image recognition algorithms. These experiments and the results are presented in this paper.