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In all technical sectors there is an increasing trend towards online monitoring of components and structures, but especially in the presence of extreme loads and environments. Many fiber-reinforced composites are used in aerospace applications, where a continuous monitoring can help to improve safety. Additionally, in the newer field of hydrogen fueled electric vehicles, the safety of the hydrogen pressure vessels is still of concern to many users. In order to improve the long-term safety of such components, filament-based sensors can be incorporated into the structures and coupled with algorithms and simulations in order to make assessments and predictions, reducing the risk of catastrophic failure. In order to realize this future, integratable sensors must be developed with the application in mind. This means that the sensors must be compatible with current manufacturing processes and withstand further processing steps. Filament based sensors are predestined for such fiber reinforced composites, due to the endless filament form. Electrical resistance-based sensors allow for the simple measurement and evaluation of data in comparison with expensive and complex optical sensors. The melt spinning of such conductive filaments also allows for multilayered sensor development, which can be insulated from the environment, reducing contact with the reinforcing carbon fiber and therefore reducing a short circuit. The goal of this work is to develop melt spun filaments and investigate its suitability for strain sensing applications once embedded in fiber reinforced composites. In this work, specifically the production of TPU and PP bicomponent filaments will be presented, which are specifically designed for use as strain sensors in composite structures. These filaments are then analyzed regarding their strain sensing response as single filaments as well as integrated into carbon-fiber reinforced laminate tested under tensile tests; strain response is simultaneously recorded. [ABSTRACT FROM AUTHOR]

Today, the transport sector is responsible for almost a quarter of primary energy consumption and associated global CO2 emissions, with the vast majority of emissions coming from road transport. To limit climate change to the 2°C targeted in the Paris Agreement, CO2 emissions must be reduced by nearly 60% by 2050, compared to 2013. Since some sectors, such as aviation and maritime transport, are particularly difficult to decarbonize, road transport is expected to require a nearly 100% reduction in emissions. In addition, the transport sector is responsible for about 20% of the projected increase in both global energy demand and greenhouse gas emissions by 2040. With raising fuel prices and public awareness, more people are shifting towards greener alternatives. This leads to major innovations in the fields of electric mobility and has started also gaining traction in the field of hydrogen fuel cell production. One major aspect of fuel cell vehicles is the pressure tanks that hold hydrogen at extremely high pressures. These tanks are subject to wear and damage, requiring regular scheduled maintenance to identify problems at their initial stages. The goal of this work is to investigate the influence of different production variables of fiber-based nanocomposites on their suitability as resistive based sensors. This sensor technology will then aim towards identifying possible strains or damages that a pressure tank might be subjected to at an early stage. This early identification process limits costs and hazardous risks, by detecting problems without the need of scheduled tests that can cause disruption or inconvenience to the user. In this work bicomponent filaments of a conductive core and insulating sheath are developed. The specific parameters investigated in this thesis are the winding speeds and the ratio of the core to sheath areas. Through this work, influences on the mechanical, electrical and electro-mechanical properties are investigated in order to provide a starting point for further development. [ABSTRACT FROM AUTHOR]

The properties of man-made yarns heavily depend on the filaments structure. During the melt spinning process the orientation and crystallization process is influenced by the temperature and stress profiles. Thereby, the local cooling and the strain behaviour of the filaments are defined by the cooling and haul-off conditions. [ABSTRACT FROM AUTHOR]

The article discusses research which investigated the possible application of biopolymer textile substrates in automotive interiors. Topics explored include the estimated quantity of textile materials in an average automobile, the need for automotive fabrics to have functional and aesthetic qualities, and the testing of friction, filament behavior, and stress behavior of polylactic acid and polyhydroxybutyrate (PLA-PHB) blended fabrics.