Two ways to apply optical fibers in textile structures textile structures actively emitting light sensors applied in textile structures optical fibers emitting light on their jackets sensor-optical fibers (SOF) Dipl.-Ing. Elke Thiele, Dipl.-Ing. Reinhard Helbig,, Dipl.-Ing. Frank Weigand, Dipl.-Ing. (FH) Rolf Arnold, Dr.-Ing. Monika Seeger Content Terminology Motivation Potential Applications Shining textiles Sensing textiles 1
Terminology- What a textile fibre-optical lighting system is made up of ~ characteristics Source of light (LED, metal vapour lamp, halogen lamp) Connecting systems (fibers, plugs, directly bonded joint) Optical fibers emitting light on their jackets (glass, plastic material) textile component to position optical fibers (Stfi variant: weaving/warp-knitting/knitting/embroidering) No emission of heat or UV radiation Electric current is separated from place of light emission Structures can be applied in slightly wet areas Basics Fiber optic cable construction is characterized by core cladding coating Total internal reflection confines light within optical fibers. the cladding has a lower refractive index, light rays reflect back into the core if they encounter the cladding at a shallow angle (blue lines) A ray that exceeds a certain critical angle escapes from the fiber (pink line) The surface of the fiber starts to shine. 2
Textile structures actively emitting light luminescent net In 2000, STFI-first developed product based on optical fibers; Distribution by bedea akzent Net manufacturer: Sächsische Netzwerke Huck GmbH Double needle bar warp-knitting machine GWM, OF- PMMA Ø = 1mm 150W- metal vapour lamp Textile structures actively emitting light luminescent net credits: bedea 3
Textile structures actively emitting light Knits: e.g. special-purpose clothes, children`s wear, safety clothes; Machine used: Universal double needle bar flat knitting machine Universal weft-insertion of optical fibers Jacquard wovens: e.g. structures to decorate walls, structures to serve as wall partition, luminescent sails, stage lighting systems Machine used: STB jacquard loom Optical fibers inserted in warp direction, Textile structures actively emitting light Dot-type or line-shape type embroidered structures: e.g. table cloths,window slats, Machine used: ZSK Ribbon-type knits: e.g. ribbons to serve as lighting elements on table cloths Machine used: Raschelina single needle bar warpknitting machine RD3MT2 8/420 4
Textile structures actively emitting lightsources of light SZMS e.v. LED LED for portable textile structures of up to about 0.5m² Light projector with bedea metal vapour lamp Light projector for large stationary textile structures of up to 250 m² Textile structures actively emitting light range of luminous power Minolta exposure meter applied directly on textile structure (captures about 70 cm²) straight positioned optical fibers: from about 0.5 lx to 5 lx arch-like positioned optical fibers: about 50 lx compare: sunlight 127.000 lx Daylight in workshop 640 lx Electric light in workshop at night 180 lx Night of a full moon 0,2 lx 5
Terminology What a textile structure with sensor-optical fibers is made up of ~ Measuring instrument Connecting system (forerunner fibers, end-runner fibers, plugs,.. FBG Sensor-optical fibers (glass, plastic materials) Textile structure to position sensoroptical fibers Motivation Motivation of integrating fiber optical sensors in textile structures combination of reinforcement and monitoring To achieve: optimized connection of the sensor and the structure simple application process of the sensors The whole textile structure becomes a sensor three- dimensional sensor Protection of the sensors against overload 6
Potential Options of positioning the sensors in textiles textile processing Examples of sensor positioning weaving warp knitting knitting nonwoven embroidering finishing Potential The sensor systems used by stfi so far OTDR based on silica optical fibers OTDR based on polymer optical fibers FBG based on silica optical fibers Brillouin scattering based on silica optical fibers Chemical sensing silica or polymer optical fibers Measuring of attenuation on silica optical fibers Measuring of attenuation on polymer optical fibers 7
Only light is transported, no electric current No puncture in case of lightning System works under extreme conditions (moisture, wetness, vibration, radioactivity) The same fibers as used in telecommunication = low priced Silica optical fibers are sensitive to bending and mechanical stress Minimum bending radius without increase of optical attenuation is 32 mm Fibers would break if they were not protected by coating and cabling materials 8
schedule Design Sensortechnische Gestaltung Bautechnische der of the textile Zielstellungen Textilstruktur structure Materials Design testing processing Sensortechnische Bautechnische Installation Zielstellung Modification of: machines and technology testing Installation technology Testing / calibration Application- structural engineering Motivation During lifetime, buildings lose their initial stability either because of aging or overload. Reliable systems for reconstruction of buildings are needed to ensure safety. Objective Development of textile structure for application on the building site. The tasks of the textiles are to reinforce and monitor structures at risk. Application For reconstruction to reinforce and monitor the structural health of buildings. 9
Application- structural engineering 2D- composite, sensor integrated reinforcement strengthening system based on carbon plates monitoring measuring system based on FBG- sensors Application- structural engineering Design Sensortechnische Gestaltung Bautechnische der of the textile Zielstellungen Textilstruktur structure Materials Design testing processing Sensortechnische Bautechnische Installation Zielstellung Modification of: machines and technology testing Installation technology Testing / calibration 10
Application- structural engineering embroidery ground Woven fabric, carbon length: 0.60 m-50m width: 150 mm; 10mm-1000mm thickness: 0.90 mm-5 mm E-module:30 kn/mm² tensile strength: 300kN/m Fiber optical sensor Corning SMF-28e diameter 125 µm Minimal bending radius 30 mm FBG produced by AOS GmbH wave-length: 1550 nm threads PES (Grilon, Alterfil) Application- structural engineering ZSK STICKTRONIC SGW 0100 800 W- Kopf; 800rev/min 11
Application- structural engineering Application- structural engineering Test of the function of the sensors 12
Application- structural engineering reference block: ferroconcrete strengthened with a composite Test equipment : FBG, redundancy by strain gauge; inductive displacement transducer optical fiber strain gauge Application- geosynthetics Motivation Stabilization and monitoring of critical soil structures Objective Development of a geotextile with integrated optical fiber sensors Application Dams Dikes Coal mines 13
Vliesraschelmaschine RS 3 MSUS-V with weft insertion Specification special warp knitting machine parameters - gauge 6 E - 3 bars (1 ground bar, 2 guide bars to take up the sensors and the strengthening fibres) - working width 165 inches Critical mechanical impacts on fiber optical sensors tube Sensor fibers or reinforcing fibers Weft insertion Ground yarn Nonwoven 14
Analysing methods of critical mechanical impacts on fiber optical sensors Test with special Polymer optical fiber (POF) Analysing methods of critical mechanical impacts on fiber optical sensors OTDR equipment used to check the quality of fiber optical sensors during the manufacturing process 15
Textile machine adaptation Analysing methods of critical mechanical impacts on fiber optical sensors are the basis for the textile machine adaptation Single needle bar raschel knitting machine RS 3 MSUS-V Advantages: - very dense, - semi-open or - open structures can be produced 0 direction Reinforcing fibers in 0 and 90 direction sensors in 0 direction 90 direction 16
Application- geosynthetics FIELD TESTS Dike of the river Mulde 1 st test in Sollnitz near the town of Dessau 17
FIELD TESTS FIELD TESTS 18
FIELD TESTS FIELD TESTS gravity dam in Solina, Poland 2 nd test in Solina, Poland downriver of a retaining wall 19
Optimization of the measurement system Calibration of the geotextile- fiber optical sensor system Thank you for your attention! 20