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Nanoparticles extracted from plants or textile waste are promising candidates for the design of sustainable materials. In this thesis, I explored how nanoparticles extracted from trees and from Kevlar and cotton textile wastes can be processed to form lightweight composite foams. The heat transfer and other functional properties such as electromagnetic shielding have been related to the structure, composition, and processing of the composite foams. Specifically, upcycled aramid nanofibers (upANFA) with a small diameter were derived from Kevlar yarn. The upANFA could be combined with wood-based cellulose nanofibrils (CNF) to produce moisture-resilient anisotropic foams with a very low thermal conductivity perpendicular to the aligned nanofibrils. The very low radial thermal conductivity was related to the strong interfacial phonon scattering between the very thin upANFA and CNF in the hybrid foam walls. Aqueous dispersions of multiwalled carbon nanotubes (MWCNT) and cellulose nanocrystals (CNC) were used to form anisotropic foams with an anisotropic heat transport and orientation-dependent electromagnetic interference shielding efficiency (EMI-SE). The low-density (31 kg m–3) CNC-MWCNT hybrid foams with 22 wt% MWCNT were mechanically robust along the axial direction (Young’s Modulus of 1200 kPa). The foams displayed an absorption-dominated EMI-SE of up to 41–48 dB and transferred heat favorably along the axial direction compared to the radial, meaning that this material could be useful in devices that require directional heat management and electromagnetic shielding. A novel wet-foaming with subsequent freeze-casting process was developed to produce air- and ice-templated foams based on methylcellulose, CNF, and tannic acid. The air- and ice-templated foams displayed a high specific compression stiffness compared with other CNF-based materials while maintaining good insulation properties. Hybrid foams based on CNC extruded from cotton textile waste and wood-based

Nanoparticles extracted from plants or textile waste are promising candidates for the design of sustainable materials. In this thesis, I explored how nanoparticles extracted from trees and from Kevlar and cotton textile wastes can be processed to form lightweight composite foams. The heat transfer and other functional properties such as electromagnetic shielding have been related to the structure, composition, and processing of the composite foams. Specifically, upcycled aramid nanofibers (upANFA) with a small diameter were derived from Kevlar yarn. The upANFA could be combined with wood-based cellulose nanofibrils (CNF) to produce moisture-resilient anisotropic foams with a very low thermal conductivity perpendicular to the aligned nanofibrils. The very low radial thermal conductivity was related to the strong interfacial phonon scattering between the very thin upANFA and CNF in the hybrid foam walls. Aqueous dispersions of multiwalled carbon nanotubes (MWCNT) and cellulose nanocrystals (CNC) were used to form anisotropic foams with an anisotropic heat transport and orientation-dependent electromagnetic interference shielding efficiency (EMI-SE). The low-density (31 kg m–3) CNC-MWCNT hybrid foams with 22 wt% MWCNT were mechanically robust along the axial direction (Young’s Modulus of 1200 kPa). The foams displayed an absorption-dominated EMI-SE of up to 41–48 dB and transferred heat favorably along the axial direction compared to the radial, meaning that this material could be useful in devices that require directional heat management and electromagnetic shielding. A novel wet-foaming with subsequent freeze-casting process was developed to produce air- and ice-templated foams based on methylcellulose, CNF, and tannic acid. The air- and ice-templated foams displayed a high specific compression stiffness compared with other CNF-based materials while maintaining good insulation properties. Hybrid foams based on CNC extruded from cotton textile waste and wood-based

Nanoparticles extracted from plants or textile waste are promising candidates for the design of sustainable materials. In this thesis, I explored how nanoparticles extracted from trees and from Kevlar and cotton textile wastes can be processed to form lightweight composite foams. The heat transfer and other functional properties such as electromagnetic shielding have been related to the structure, composition, and processing of the composite foams. Specifically, upcycled aramid nanofibers (upANFA) with a small diameter were derived from Kevlar yarn. The upANFA could be combined with wood-based cellulose nanofibrils (CNF) to produce moisture-resilient anisotropic foams with a very low thermal conductivity perpendicular to the aligned nanofibrils. The very low radial thermal conductivity was related to the strong interfacial phonon scattering between the very thin upANFA and CNF in the hybrid foam walls. Aqueous dispersions of multiwalled carbon nanotubes (MWCNT) and cellulose nanocrystals (CNC) were used to form anisotropic foams with an anisotropic heat transport and orientation-dependent electromagnetic interference shielding efficiency (EMI-SE). The low-density (31 kg m–3) CNC-MWCNT hybrid foams with 22 wt% MWCNT were mechanically robust along the axial direction (Young’s Modulus of 1200 kPa). The foams displayed an absorption-dominated EMI-SE of up to 41–48 dB and transferred heat favorably along the axial direction compared to the radial, meaning that this material could be useful in devices that require directional heat management and electromagnetic shielding. A novel wet-foaming with subsequent freeze-casting process was developed to produce air- and ice-templated foams based on methylcellulose, CNF, and tannic acid. The air- and ice-templated foams displayed a high specific compression stiffness compared with other CNF-based materials while maintaining good insulation properties. Hybrid foams based on CNC extruded from cotton textile waste and wood-based

Nanoparticles extracted from plants or textile waste are promising candidates for the design of sustainable materials. In this thesis, I explored how nanoparticles extracted from trees and from Kevlar and cotton textile wastes can be processed to form lightweight composite foams. The heat transfer and other functional properties such as electromagnetic shielding have been related to the structure, composition, and processing of the composite foams. Specifically, upcycled aramid nanofibers (upANFA) with a small diameter were derived from Kevlar yarn. The upANFA could be combined with wood-based cellulose nanofibrils (CNF) to produce moisture-resilient anisotropic foams with a very low thermal conductivity perpendicular to the aligned nanofibrils. The very low radial thermal conductivity was related to the strong interfacial phonon scattering between the very thin upANFA and CNF in the hybrid foam walls. Aqueous dispersions of multiwalled carbon nanotubes (MWCNT) and cellulose nanocrystals (CNC) were used to form anisotropic foams with an anisotropic heat transport and orientation-dependent electromagnetic interference shielding efficiency (EMI-SE). The low-density (31 kg m–3) CNC-MWCNT hybrid foams with 22 wt% MWCNT were mechanically robust along the axial direction (Young’s Modulus of 1200 kPa). The foams displayed an absorption-dominated EMI-SE of up to 41–48 dB and transferred heat favorably along the axial direction compared to the radial, meaning that this material could be useful in devices that require directional heat management and electromagnetic shielding. A novel wet-foaming with subsequent freeze-casting process was developed to produce air- and ice-templated foams based on methylcellulose, CNF, and tannic acid. The air- and ice-templated foams displayed a high specific compression stiffness compared with other CNF-based materials while maintaining good insulation properties. Hybrid foams based on CNC extruded from cotton textile waste and wood-based

The goal of this dissertation was to design, synthesize, and analyze novel aramid fibers by covalently grafting nanocellulose through electron beam irradiation. These nanocellulose functionalized fibers showed enhanced strength and larger surface areas, which improves their performance and applicability in fiber-reinforced composites. Unmodified aramid fibers have smooth and chemically inert surfaces, which results in poor adhesion to many types of resins. Nanocellulose was chosen as the ideal filler to functionalize the fibers due to its reactive surface and high strength-to-weight ratio. Aramid fibers were further modified by radiation-induced crosslinking reactions as a means to avoid scission of the polymeric backbone and to further increase the fiber strength.An indirect radiation-induced grafting approach was used for synthesizing these novel nanocellulose-grafted aramid fibers while avoiding the irradiation of nanocellulose. The fibers were irradiated using the e-beam linear accelerator (LINAC) at the Medical Industrial Radiation Facility (MIRF) at the National Institute of Standards and Technology (NIST). After the irradiation, the fibers were kept in an inert atmosphere and then mixed with a nanocellulose solution for grafting. The grafted fibers were evaluated by gravimetric analysis, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and nuclear magnetic resonance (NMR) spectroscopy. The mechanical properties of the synthesized fibers were studied by single fiber tensile tests. Aramid fibers were also irradiated at the MIRF in the presence of acetylene gas and triacrylate solution as a means to induce crosslinking reactions. These fibers were irradiated at both low doses and high dose rates at room temperature. A mechanism for the crosslinking of aramid fibers was proposed in this dissertation. Mechanical testing of the fibers after crosslinking showed an increase in the strength of the fibers of up to 15%. Ultra-high mole

The secondary operations of composite parts are performed following thermal cure processes, which generate the final dimensions with desired tolerance and quality specifications. High-strength composites, on the other hand, especially aramid fiber-reinforced polymers (AFRP), are not suitable for conventional machining operations due in part to high operational costs and limited surface quality characterized by fuzziness and delamination. Abrasive Water Jet (AWJ) has been recently shown promising results in obtaining improved surface quality while ensuring significant cost advantages. This study investigates the AWJ processing of AFRP by implementing the analysis of variance and response surface methods. The effects of the control parameters (sand ratio, pressure, stand-off-distance, and feed rate) on the surface quality metrics (surface roughness, kerf angle, and dimensional error) are identified and comparatively evaluated. The surface quality of the AWJ processed AFRP specimens are investigated using Scanning Electron Microscopy (SEM). The trade-offs between the measured tolerances and surface roughness values are identified via a new genetic algorithm approach: Non-dominated Sorting Genetic Algorithm (NSGA-III). Also, operation regions are determined using the generated Pareto curves while improving the quality of various features of an AFRP component, critical to its functional performance during extended service life. As a result, the lowest Ra values obtained were 4.135 mu m for trimming, 5.962 mu m for pocketing, and 4.696 mu m for the hole-making operation. The maximum error in the accuracy of operating regions yields to 7% with independent measurements for validation., Turkiye Bilimsel ve Teknolojik Arastirma Kurumu [118M027], The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Turkiye Bilimsel ve Teknolojik Arastirma Kurumu, (grant number 118M027).

The secondary operations of composite parts are performed following thermal cure processes, which generate the final dimensions with desired tolerance and quality specifications. High-strength composites, on the other hand, especially aramid fiber-reinforced polymers (AFRP), are not suitable for conventional machining operations due in part to high operational costs and limited surface quality characterized by fuzziness and delamination. Abrasive Water Jet (AWJ) has been recently shown promising results in obtaining improved surface quality while ensuring significant cost advantages. This study investigates the AWJ processing of AFRP by implementing the analysis of variance and response surface methods. The effects of the control parameters (sand ratio, pressure, stand-off-distance, and feed rate) on the surface quality metrics (surface roughness, kerf angle, and dimensional error) are identified and comparatively evaluated. The surface quality of the AWJ processed AFRP specimens are investigated using Scanning Electron Microscopy (SEM). The trade-offs between the measured tolerances and surface roughness values are identified via a new genetic algorithm approach: Non-dominated Sorting Genetic Algorithm (NSGA-III). Also, operation regions are determined using the generated Pareto curves while improving the quality of various features of an AFRP component, critical to its functional performance during extended service life. As a result, the lowest Ra values obtained were 4.135 mu m for trimming, 5.962 mu m for pocketing, and 4.696 mu m for the hole-making operation. The maximum error in the accuracy of operating regions yields to 7% with independent measurements for validation., Turkiye Bilimsel ve Teknolojik Arastirma Kurumu [118M027], The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Turkiye Bilimsel ve Teknolojik Arastirma Kurumu, (grant number 118M027).

This paper examines the influence of weaving variables such as yarn count, number of layers, warp and weft ratio, materials of the top layer, weft density and interlocking cell shape, and size on the thermal performance of multilayer interlocked woven fabrics. A split-plot design was used to construct a total of 64 fabric structures, which were assessed for thermal performance in terms of resistance to convective, conductive, and radiative heat. It was found that, for equal weft density and yarn number, protective performance improved with the number of fabric layers and with the presence of air cells between these layers, especially if air was not trapped within and could rather pass freely between the cells. An optimal combination of factors for the thermal response to the three types of heat was established via a Derringer–a much needed desirability function. The results of this paper are useful for identifying the interaction between configuration parameters and thermal performance, and hence for the design of improved heat protective clothing, Postprint (published version)

New materials are currently being developed for applications in transformer design. With the useful life of transformers now determined by solid insulation conditions, a better understanding of aging kinetics is important in order to improve electrical system management and planning from the technical and economic points of view. This paper summarizes an investigation of the effects of impregnating aramid and cellulose/aramid papers (Nomex 410 and 910) with insulation fluids (Nynas Polaris and Luminol Tri) at thermally accelerated conditions (170 °C) on their mechanical properties. It was found that Nomex 410 (100% aramid) showed only a small change in tensile strength (~5% decrease) after accelerated aging (around 7500 h). However, its elongation capacity was significantly reduced (~45–70% decrease for dry and wet Nomex 410, respectively) by the end of the aging process, probably due to hydrolysis. In addition, the interaction between water and aramid hydrogen bonds at high temperatures produced the rupture and then, the randomly rebuilt of these bonds in meta-aramid fibres, thereby reducing its plastic deformation capacity. In the case of Nomex 910 (aramid enhanced cellulose), its mechanical properties were maintained for a longer time than those of thermally upgraded Kraft paper (TUK), as measured by the retained percentage of tensile index. However, when the tensile index was used instead of the retained percentage, TUK showed a higher tensile index value than Nomex 910 during the initial stage, while the values for both papers became similar during the second stage. It is only at the end of the aging process that Nomex 910 presented an advantage over TUK paper due to the addition of the aramid fibres. It was also found that the inception fractures in Nomex 910, as a fibrous layered composite paper, start in the weakest part of the composite, probably in the central cellulose layer. The fracture line follows the weakest path, avoiding the aramid fibres. The resu

[ES] Con la ejecución de este trabajo final de master se pretende obtener no-tejidos a partir de residuos textiles tales como borra textil larga, residuo de fibra de aramida o poliéster. Previamente se describirán las especificaciones técnicas que deberá cumplir el producto obtenido, para dar respuestas a determinadas solicitudes. (aislamiento acústico, aislamiento térmico y calorimétrico ) Para ello, primero se realizará una investigación de las técnicas de obtención de los no-tejidos y se utilizará el equipo de Air Laid y la carda para el desarrollo de las muestras. Finalmente, los no-tejidos que se obtengan se caracterizarán en laboratorio para determinar el nivel de aislamiento acústico, aislamiento térmico y cono calorimétrico, y se analizarán los resultados obtenidos., [EN] With the execution of this project, the objective has been to obtain ¿nonwovens¿ from textile residues. Firstable, I have carried out an investigation of the techniques of obtaining the ¿nonwovens¿ and after this, I have used the Airlaid equipment for the development of the samples. Finally, It has been characterized the ¿nonwovens¿ obtained in the laboratory to determine the level of sound insulation, thermal insulation and fire behavior, and the results obtained will be analyzed.

[ES] Con la ejecución de este trabajo final de master se pretende obtener no-tejidos a partir de residuos textiles tales como borra textil larga, residuo de fibra de aramida o poliéster. Previamente se describirán las especificaciones técnicas que deberá cumplir el producto obtenido, para dar respuestas a determinadas solicitudes. (aislamiento acústico, aislamiento térmico y calorimétrico ) Para ello, primero se realizará una investigación de las técnicas de obtención de los no-tejidos y se utilizará el equipo de Air Laid y la carda para el desarrollo de las muestras. Finalmente, los no-tejidos que se obtengan se caracterizarán en laboratorio para determinar el nivel de aislamiento acústico, aislamiento térmico y cono calorimétrico, y se analizarán los resultados obtenidos., [EN] With the execution of this project, the objective has been to obtain ¿nonwovens¿ from textile residues. Firstable, I have carried out an investigation of the techniques of obtaining the ¿nonwovens¿ and after this, I have used the Airlaid equipment for the development of the samples. Finally, It has been characterized the ¿nonwovens¿ obtained in the laboratory to determine the level of sound insulation, thermal insulation and fire behavior, and the results obtained will be analyzed.

[ES] Con la ejecución de este trabajo final de master se pretende obtener no-tejidos a partir de residuos textiles tales como borra textil larga, residuo de fibra de aramida o poliéster. Previamente se describirán las especificaciones técnicas que deberá cumplir el producto obtenido, para dar respuestas a determinadas solicitudes. (aislamiento acústico, aislamiento térmico y calorimétrico ) Para ello, primero se realizará una investigación de las técnicas de obtención de los no-tejidos y se utilizará el equipo de Air Laid y la carda para el desarrollo de las muestras. Finalmente, los no-tejidos que se obtengan se caracterizarán en laboratorio para determinar el nivel de aislamiento acústico, aislamiento térmico y cono calorimétrico, y se analizarán los resultados obtenidos., [EN] With the execution of this project, the objective has been to obtain ¿nonwovens¿ from textile residues. Firstable, I have carried out an investigation of the techniques of obtaining the ¿nonwovens¿ and after this, I have used the Airlaid equipment for the development of the samples. Finally, It has been characterized the ¿nonwovens¿ obtained in the laboratory to determine the level of sound insulation, thermal insulation and fire behavior, and the results obtained will be analyzed.

[ES] Con la ejecución de este trabajo final de master se pretende obtener no-tejidos a partir de residuos textiles tales como borra textil larga, residuo de fibra de aramida o poliéster. Previamente se describirán las especificaciones técnicas que deberá cumplir el producto obtenido, para dar respuestas a determinadas solicitudes. (aislamiento acústico, aislamiento térmico y calorimétrico ) Para ello, primero se realizará una investigación de las técnicas de obtención de los no-tejidos y se utilizará el equipo de Air Laid y la carda para el desarrollo de las muestras. Finalmente, los no-tejidos que se obtengan se caracterizarán en laboratorio para determinar el nivel de aislamiento acústico, aislamiento térmico y cono calorimétrico, y se analizarán los resultados obtenidos., [EN] With the execution of this project, the objective has been to obtain ¿nonwovens¿ from textile residues. Firstable, I have carried out an investigation of the techniques of obtaining the ¿nonwovens¿ and after this, I have used the Airlaid equipment for the development of the samples. Finally, It has been characterized the ¿nonwovens¿ obtained in the laboratory to determine the level of sound insulation, thermal insulation and fire behavior, and the results obtained will be analyzed.

We prepared microporous aramid films through a simple, inexpensive and green way, using ionic liquids (IL) as porosity promoters. Commercial poly(m-phenylene isophthalamide) (MPIA) films with different IL proportions were prepared, and then microporous films were obtained by removing the IL in distilled water. Microporous films presented density values between 0.34 and 0.71 g⋅cm (around five times lower to commercial MPIA), with a homogeneous and controlled cellular morphology dependent on the proportion of the IL, showing cell sizes in the microcellular range (radii between 1 and 8 µm). Thermal, mechanical and electrical properties (specifically ionic conductivity) of the aramid films were analyzed to evaluate the influence of the IL proportion. Finally, it was observed that the MPIA/IL system presented a reversible thermally induced phase-separation process around 60 °C, which was characterized through AFM-Raman images and spectra, together with the variation of the ionic conductivity.

El trabajo que conforma Tesis Doctoral titulada Polímeros funcionales. Aplicaciones como sensores y materiales de altas prestaciones se encuadra en el ámbito científico y tecnológico de los materiales avanzados para aplicaciones específicas. En este marco se han diseñado materiales funcionales con aplicaciones en protección y seguridad civil, industria y medio ambiente. Concretamente se han elaborado sensores químicos poliméricos cromogénicos y fluorogénicos de explosivos (TNT), cationes metálicos, alta acidez y agua. Los receptores orgánicos utilizados son insolubles en agua, pero su incorporación a polímeros con el grado de hidrofilia adecuada ha permitido la obtención de polímeros solubles en este medio, así como geles capaces de detectar a las moléculas de interés en entornos acuosos. Además, se han preparado materiales de altas prestaciones, concretamente poliamidas aromáticas, con grupos funcionales que aportan características de interés como color, potencial funcionalización adicional, o mejores propiedades mecánicas y térmicas., The work constituting this Thesis lies within the scientific and technological field of advanced materials for specific applications. In this framework, functional materials with applications in civil protection and security, industry and environment have been designed. Specifically, fluorogenic and chromogenic polymeric chemosensors towards explosives (TNT), metal cations, high acidity and water were developed. The organic receptors used were insoluble in water, but their incorporation into polymers with the appropriate degree of hydrophilicity allowed for the preparation of water soluble polymers, as well as gels capable of detecting target molecules in aqueous environments. In addition, high performance materials were prepared, particularly aromatic polyamides containing functional groups that provide interesting features, such as color, additional functionalization potential, or better mechanical and thermal properties.

The use of synthetic fibres has been reported to enhance the performance of asphalt pavement materials in terms of permanent deformation, fatigue and thermal cracking. However, limited results about the benefits of synthetic fibres in the reinforced warm-mix asphaltic materials, and the exact mechanism of reinforcing the binding part in pavement structures is still unclear. This research aims firstly to examine the material at the warm mixed mortar level using a combination of two synthetic fibres (aramid and polyolefin) to conclude its fracture performance. Several laboratory tests were performed using specially designed experimental tools. Samples of three different fibre contents (0.05%, 0.1% and 0.5% of specimen weight) and two fibre lengths (19 and 38mm) were evaluated. In particular, pull-out tests, whose objective was to explore the interaction of fibre-matrix demonstrated a matrix-type of fracture; meaning that the adhesion of fibre-matrix is higher than the strength of the matrix itself, which implies a benefit of adding fibre to a mixture at high service temperature. Summary Moreover, direct tension tests were carried out with both monotonic and cyclic loading to measure the effect of the synthetic fibres on tensile strength, fracture energy and fatigue life of reinforced warm mixes under monotonic and cyclic tension load, respectively. These tension experiments concluded improvements on mechanical characteristics of warm mixed asphalt mortars when fibres were added, mainly applying higher dosages than the recommended by the fibres supplier. Overall, the current results elucidated that implementing dedicated material studies at micro-scales can assist on understanding the material performance and tailoring systems beyond sometimes recommended reinforcement dosages by the suppliers. Finally, a semi-circular bending test was performed as the largest scale of this research using various fibre amount composition as well as fibre length inside the bitu, Civil Engineering | Structural Engineering

The use of synthetic fibres has been reported to enhance the performance of asphalt pavement materials in terms of permanent deformation, fatigue and thermal cracking. However, limited results about the benefits of synthetic fibres in the reinforced warm-mix asphaltic materials, and the exact mechanism of reinforcing the binding part in pavement structures is still unclear. This research aims firstly to examine the material at the warm mixed mortar level using a combination of two synthetic fibres (aramid and polyolefin) to conclude its fracture performance. Several laboratory tests were performed using specially designed experimental tools. Samples of three different fibre contents (0.05%, 0.1% and 0.5% of specimen weight) and two fibre lengths (19 and 38mm) were evaluated. In particular, pull-out tests, whose objective was to explore the interaction of fibre-matrix demonstrated a matrix-type of fracture; meaning that the adhesion of fibre-matrix is higher than the strength of the matrix itself, which implies a benefit of adding fibre to a mixture at high service temperature. Summary Moreover, direct tension tests were carried out with both monotonic and cyclic loading to measure the effect of the synthetic fibres on tensile strength, fracture energy and fatigue life of reinforced warm mixes under monotonic and cyclic tension load, respectively. These tension experiments concluded improvements on mechanical characteristics of warm mixed asphalt mortars when fibres were added, mainly applying higher dosages than the recommended by the fibres supplier. Overall, the current results elucidated that implementing dedicated material studies at micro-scales can assist on understanding the material performance and tailoring systems beyond sometimes recommended reinforcement dosages by the suppliers. Finally, a semi-circular bending test was performed as the largest scale of this research using various fibre amount composition as well as fibre length inside the bitu, Civil Engineering | Structural Engineering

The stab resistance of textiles and membranes is a very important property for several areas. For many applications, which are used in the protection area, aramid woven structures are normally used. A main problem of these panels is the missing yarn friction, whichleads to a high yarn slippage. It allows a knife or another sharp blade to penetrate the fabric, because the yarns slide apart. One solution is to reduce the slippage of the yarns during the penetration through the knife and resultant of this effect a higher absorbing of the impact energy. To determine the influence of this effect, fourdifferent woven aramidstructures with different properties and pattern, were tested against shift by determining the seam slippage by using the fixed seam opening method. Due to this, the behaviourof stab resistance of the different aramid fabrics were tested according to theVPAM test instruction “Stab-and impact protection”. The interdependence betweenthe yarn slippage and the stab penetration was tested. A better understanding of this process allows improving fabrics for membranes against stab attacks in future.

The objective of this work is to examine the relationship between structure (both molecular and morphological structure) and properties of high strength fibers. The superior performance of the high strength fibers is predicated on the development of a highly aligned molecular structure that allows the polymer to exhibit a superior strength in the axial direction of the fiber. Armor manufacturers have exploited the inherent strength of these materials to develop body armor that continues to defeat ever-increasing threats. However, even an ideal molecular structure will be subjected to a potentially hydrolytic or oxidative environment during use, which can reduce the high strength of these fibers, and impact their ability to protect the wearer. The effect of the wear environment on the molecular structure, which is responsible for the high strength of these fibers, has not been well understood by the scientific community. In this work, the chemical mechanisms of degradation were investigated at the molecular level to understand the effect of the environmental conditions on crystallinity, orientation, and molecular weight. The chemical mechanism and kinetics elucidated from these measurements are used to understand the reduction in strength of these materials after degradation. Hydrolysis was found to be the predominant mechanism of degradation for polybenzobisoxazole and goes to irreversible chain scission. Hydrolysis is also the primary mechanism of degradation for aramid fibers. Ultra-high molecular weight polyethylene (UHMWPE) fibers undergo an oxidative mechanism of degradation, and the activation energy for this mechanism was calculated. Additionally, the release of acids from aramid copolymer fibers, and the performance of these fibers in hydrolytic and thermooxidative environments were studied to determine that hydrolytic degradation is the predominant degradation mechanism for these fibers. Exploratory research was also performed in an effort to improve the st

This paper describes the mechanical behaviour of ropes used for deep sea oceanographic operations. First the requirements of deep sea handling ropes are presented. Two high performance fibres are commonly used, aramid co-polymer and high modulus polyethylene (HMPE), and these are then compared. Results from tests on single fibres and 50 ton break load braided ropes are presented, which show that the initial stiffness of a new HMPE rope increases with load level in a bedding-in process resulting from both molecular alignment and construction reorientation. The aramid rope is less sensitive to this effect and shows a high stiffness from first loading. Measurements made at sea on oceanographic ropes of both materials using an elastic recoil method are presented, and apparent modulus values are consistent with laboratory measurements. Once both ropes have been fully bedded-in the HMPE is significantly stiffer, particularly under dynamic loads. Creep tests indicate that aramids creep less quickly than HMPE under constant loads over a 6 h period at 20 °C. Bending over sheave tests indicate longer lifetimes for the aramid but further tests on wet aramid are required to complete this conclusion. Highlights ► Original data on the mechanical behaviour of two types of deep sea handling rope. ► New results from measurements at sea. ► A discussion of the relative merits of aramid and HMPE fibre ropes for this application.

Because of their high initial properties, aramid geotextiles have been used for a decade for ground reinforcement. Today, the geotextiles manufacturers think about their use in alkaline grounds. However there are few data on the long-term behaviour of aramid fibres under these conditions. Consequently, a durability study in a basic environment has been carried out in order to improve understanding of the degradation mechanisms involved in ageing. On that purpose, the physico-chemical characteristics as well as the surface state and the mechanical properties of the Twaron 1000 fibres have been followed at different ageing times., Du fait de leurs propriétés initiales élevées, les géotextiles à base de fibres aramides sont utilisés depuis une dizaine d'années pour le renforcement des sols. Aujourd'hui, les fabricants de géotextiles envisagent leur utilisation dans les sols alcalins. Cependant le comportement à long terme des fibres aramides dans ces conditions est encore mal connu. Une étude de durabilité en milieu basique a donc été initiée afin d'apporter une compréhension approfondie des mécanismes de dégradation mis en jeu. Ainsi, les caractéristiques physico-chimiques, l'état de surface, de même que les propriétés mécaniques des fibres Twaron 1000 ont été suivis à différents temps de vieillissement.

Since the development of the first truly synthetic fibres in the late nineteenth century, scientific efforts have lead to large variety of fibres ranging from fibres for textile applications to high performance fibres used as engineering materials. Examples of high performance fibres that are often used in engineering applications are aramid, glass and carbon fibres. Based on specific tensile properties polymer fibres such as aramids outperform glass and carbon fibres, but a major concern is, however, their behaviour under compressive loading. The work presented in this thesis describes a novel approach to increase the compressive strength of aramid (or PPTA) fibres and to characterise the compressive failure behaviour of these new fibres in more detail. The new concept is based on the addition of PPTA-compatible oligomers containing reactive end-groups. These newly designed oligomers can be considered to act as a molecular ‘glue’ to locally increase lateral cohesion and hence to increase the compressive properties without reducing the axial tensile properties., Fundamentals of Advanced Materials, Aerospace Engineering

Because of their high initial properties, aramid geotextiles have been used for a decade for ground reinforcement. Today, the geotextiles manufacturers think about their use in alkaline grounds. However there are few data on the long-term behaviour of aramid fibres under these conditions. Consequently, a durability study in a basic environment has been carried out in order to improve understanding of the degradation mechanisms involved in ageing. On that purpose, the physico-chemical characteristics as well as the surface state and the mechanical properties of the Twaron 1000 fibres have been followed at different ageing times., Du fait de leurs propriétés initiales élevées, les géotextiles à base de fibres aramides sont utilisés depuis une dizaine d'années pour le renforcement des sols. Aujourd'hui, les fabricants de géotextiles envisagent leur utilisation dans les sols alcalins. Cependant le comportement à long terme des fibres aramides dans ces conditions est encore mal connu. Une étude de durabilité en milieu basique a donc été initiée afin d'apporter une compréhension approfondie des mécanismes de dégradation mis en jeu. Ainsi, les caractéristiques physico-chimiques, l'état de surface, de même que les propriétés mécaniques des fibres Twaron 1000 ont été suivis à différents temps de vieillissement.

Because of their high initial properties, aramid geotextiles have been used for a decade for ground reinforcement. Today, the geotextiles manufacturers think about their use in alkaline grounds. However there are few data on the long-term behaviour of aramid fibres under these conditions. Consequently, a durability study in a basic environment has been carried out in order to improve understanding of the degradation mechanisms involved in ageing. On that purpose, the physico-chemical characteristics as well as the surface state and the mechanical properties of the Twaron 1000 fibres have been followed at different ageing times., Du fait de leurs propriétés initiales élevées, les géotextiles à base de fibres aramides sont utilisés depuis une dizaine d'années pour le renforcement des sols. Aujourd'hui, les fabricants de géotextiles envisagent leur utilisation dans les sols alcalins. Cependant le comportement à long terme des fibres aramides dans ces conditions est encore mal connu. Une étude de durabilité en milieu basique a donc été initiée afin d'apporter une compréhension approfondie des mécanismes de dégradation mis en jeu. Ainsi, les caractéristiques physico-chimiques, l'état de surface, de même que les propriétés mécaniques des fibres Twaron 1000 ont été suivis à différents temps de vieillissement.

Since the development of the first truly synthetic fibres in the late nineteenth century, scientific efforts have lead to large variety of fibres ranging from fibres for textile applications to high performance fibres used as engineering materials. Examples of high performance fibres that are often used in engineering applications are aramid, glass and carbon fibres. Based on specific tensile properties polymer fibres such as aramids outperform glass and carbon fibres, but a major concern is, however, their behaviour under compressive loading. The work presented in this thesis describes a novel approach to increase the compressive strength of aramid (or PPTA) fibres and to characterise the compressive failure behaviour of these new fibres in more detail. The new concept is based on the addition of PPTA-compatible oligomers containing reactive end-groups. These newly designed oligomers can be considered to act as a molecular ‘glue’ to locally increase lateral cohesion and hence to increase the compressive properties without reducing the axial tensile properties., Fundamentals of Advanced Materials, Aerospace Engineering

Synthetic fiber ropes are characterized by a very complex architecture and a hierarchical structure. Considering the fiber rope architecture, to pass from fiber to rope structure behavior, two scale transition models are necessary, used in sequence: one is devoted to an assembly of a large number of twisted components (multilayered), whereas the second is suitable for a structure with a central straight core and six helical wires (1 + 6). The part I of this paper first describes the development of a model for the static behavior of a fibrous structure with a large number of twisted components. Tests were then performed on two different structures subjected to axial loads. Using the model presented here the axial stiffness of the structures has been predicted and good agreement with measured values is obtained. A companion paper (Ghoreishi, S.R. et al., in press. Analytical modeling of synthetic fiber ropes, part 11: A linear elastic model for I + 6 fibrous structures, International Journal of Solids and Structures, doi:10.1016/j.ijsolstr.2006.08.032) presents the second model to predict the mechanical behavior of a I + 6 fibrous structure. (c) 2006 Elsevier Ltd. All rights reserved.

In part I of this study it was shown that, to model synthetic fiber ropes, two scale transition models can be used in sequence. The first model (continuum model) has been presented in the part I and the present paper examines the behavior of a fibrous structure consisting of 6 helicoidal strands around a central core (1 + 6 structure). An analytical model will be presented which enables the global elastic behavior of such a cable under tension-torsion loading to be predicted. In this model, first, the core and the strands are described as Kirchhoff-Love beams and then the traction-torsion coupling behavior is taken into account for both of them. By modeling the contact conditions between the strands and the core, with certain assumptions, it is possible to describe the behavior of the cable section as a function of the degrees of freedom of the core. The behavior of the cable can thus be deduced from the tension-torsion coupling behavior of its constituents. Tensile tests have beer, performed on the core, the strands and then on a full scale 205 ton failure load cable. Finally, predicted stiffness from the analytical models is compared to the test results. (c) 2006 Elsevier Ltd. All rights reserved.

Synthetic fiber ropes are characterized by a very complex architecture and a hierarchical structure. Considering the fiber rope architecture, to pass from fiber to rope structure behavior, two scale transition models are necessary, used in sequence: one is devoted to an assembly of a large number of twisted components (multilayered), whereas the second is suitable for a structure with a central straight core and six helical wires (1 + 6). The part I of this paper first describes the development of a model for the static behavior of a fibrous structure with a large number of twisted components. Tests were then performed on two different structures subjected to axial loads. Using the model presented here the axial stiffness of the structures has been predicted and good agreement with measured values is obtained. A companion paper (Ghoreishi, S.R. et al., in press. Analytical modeling of synthetic fiber ropes, part 11: A linear elastic model for I + 6 fibrous structures, International Journal of Solids and Structures, doi:10.1016/j.ijsolstr.2006.08.032) presents the second model to predict the mechanical behavior of a I + 6 fibrous structure. (c) 2006 Elsevier Ltd. All rights reserved.

In part I of this study it was shown that, to model synthetic fiber ropes, two scale transition models can be used in sequence. The first model (continuum model) has been presented in the part I and the present paper examines the behavior of a fibrous structure consisting of 6 helicoidal strands around a central core (1 + 6 structure). An analytical model will be presented which enables the global elastic behavior of such a cable under tension-torsion loading to be predicted. In this model, first, the core and the strands are described as Kirchhoff-Love beams and then the traction-torsion coupling behavior is taken into account for both of them. By modeling the contact conditions between the strands and the core, with certain assumptions, it is possible to describe the behavior of the cable section as a function of the degrees of freedom of the core. The behavior of the cable can thus be deduced from the tension-torsion coupling behavior of its constituents. Tensile tests have beer, performed on the core, the strands and then on a full scale 205 ton failure load cable. Finally, predicted stiffness from the analytical models is compared to the test results. (c) 2006 Elsevier Ltd. All rights reserved.

Synthetic fiber ropes are characterized by a very complex architecture and a hierarchical structure. Considering the fiber rope architecture, to pass from fiber to rope structure behavior, two scale transition models are necessary, used in sequence: one is devoted to an assembly of a large number of twisted components (multilayered), whereas the second is suitable for a structure with a central straight core and six helical wires (1 + 6). The part I of this paper first describes the development of a model for the static behavior of a fibrous structure with a large number of twisted components. Tests were then performed on two different structures subjected to axial loads. Using the model presented here the axial stiffness of the structures has been predicted and good agreement with measured values is obtained. A companion paper (Ghoreishi, S.R. et al., in press. Analytical modeling of synthetic fiber ropes, part 11: A linear elastic model for I + 6 fibrous structures, International Journal of Solids and Structures, doi:10.1016/j.ijsolstr.2006.08.032) presents the second model to predict the mechanical behavior of a I + 6 fibrous structure. (c) 2006 Elsevier Ltd. All rights reserved.

In part I of this study it was shown that, to model synthetic fiber ropes, two scale transition models can be used in sequence. The first model (continuum model) has been presented in the part I and the present paper examines the behavior of a fibrous structure consisting of 6 helicoidal strands around a central core (1 + 6 structure). An analytical model will be presented which enables the global elastic behavior of such a cable under tension-torsion loading to be predicted. In this model, first, the core and the strands are described as Kirchhoff-Love beams and then the traction-torsion coupling behavior is taken into account for both of them. By modeling the contact conditions between the strands and the core, with certain assumptions, it is possible to describe the behavior of the cable section as a function of the degrees of freedom of the core. The behavior of the cable can thus be deduced from the tension-torsion coupling behavior of its constituents. Tensile tests have beer, performed on the core, the strands and then on a full scale 205 ton failure load cable. Finally, predicted stiffness from the analytical models is compared to the test results. (c) 2006 Elsevier Ltd. All rights reserved.

Katedra chemické technologie vláknitých materiálů, Dokončená práce s úspěšnou obhajobou

Large quantifies of munitions stored in the open are vulnerable to a host of initiation threats, both inadvertent and intentional in nature. An experimental flame- and fragment-resistant blanket was developed to protect such munitions and prevent sympathetic reactions when the blanket is used in concert with earthen barricades. The blanket, which consists of aramid and ceramic fibers, passed several rigorous tests in both the laboratory and in the field. The ballistic performance of the blanket offered protection from 300-g and 454-g fragments traveling at velocities of 140 m/s and 60 m/s, respectively. The blanket also provided flame protection from high temperature gas jets, as well as burning JA2 and M30 propellant, when the temperatures exceeded 1200 deg C for 10 seconds. This final report combines the research efforts of the fragment penetration study and the flame and heat blocking with fire blankets for munition protection study: U.S. Army Research Laboratory (ARL) technical report, "Fire Blanket for Munition Protection: Flame- and Heat-Blocking Properties of Advanced Materials," to be published by ARL, Aberdeen Proving Ground, Maryland.

Many fiber reinforced plastics (FRP's) have excellent corrosion resistance properties and can be engineered to have mechanical properties comparable to steel. These characteristics have promoted their use in many structural applications all over the world. Although the short-term mechanical properties of these materials are usually well documented, long-term durability issues still remain. Some of these issues are hereby summarized, mostly for the case of reinforced concrete applications. Experimental observations indicate that all fiber reinforced plastics have long term strengths which are only a fraction of the short term strength. For glass, aramid and carbon FRP's, the fraction is about 30%, 50% and 80%, respectively. In addition glass and aramid FRP's will degrade if in direct contact with concrete, in the presence of moisture, and when subjected to UV radiation. These poor durability characteristics place significant restrictions on the working stress allowables for design.

The fact that high strength polyethylene fibers do not give considerably enhanced ballistics protection relative to aramid is not understood and should be studied further. Substantial advancements in the ability to analyze the microstructure of fibers by diffraction and scattering of x-rays and neutrons are in place in various laboratories. These are being ignored, or only slowly implemented, in many places, including first rate USA research laboratories. Two laboratories, which are producing (potentially) high performance fibers of conventional polymers, are at Nara University and Tokyo Institute of Technology in Japan. Electrospinning offers fantastic opportunities to produce low denier, high performance fibers for specialized, or highly tailored applications. Recommendations: Study the mechanism of ballistics protection by aramid and polyethylene fibers and understand why polyethylene is not approx. 2x better than aramid. In particular remove the concept of "low melting point" from the realm of speculation. While the words used to describe fiber structure as determined from x-ray analysis may be imprecise, the modern data and analytical methods should be required in all significant x-ray analysis of fiber microstructure. Expect the (Japanese) laboratories of Masaru Matsuo and T. Kikutani to develop some substantially and significantly improved fibers from currently available polymers. These laboratories are worth keeping contact with. jg p.4 and 5

In this letter we present the results of XPS experiments carried out on untreated and ammonia plasma-treated aramid and ECPE fibres after exposure to DGEBA-Br. We also discuss, in the context of our own findings, aramid/epoxy and ECPE/epoxy interfacial adhesion results obtained by other researchers.

This study was conducted to determine feasibility of using ultrasonic nondestructive inspection on compression molded aramid (Kevlar) composite helmets. Results indicated detection capability for internal discontinuities voids & delaminations. Detection of number of layers of aramid does not show much promise.

This study was conducted to determine feasibility of using real time radiography nondestructive testing of compression molded aramid (Kevlar) composite helmets. Results indicated a practical capability to inspect for defects and number of layers of aramid in the helmet.

S-N fatigue and creep-rupture data have been obtained for nylon 6,6 single fibers, interlaced yarns, and small ropes under a variety of loading conditions. The results show a similar degradation rate at each level of structure, with no apparent influence of interfiber effects. Cyclic lifetimes of single fibers of nylon 6,6 as well as polyester and aramid can be predicted from a creep rupture model. Consistent with this model, the time to failure is insensitive to frequency over a broad range. For each level of structure the strain at failure is the same whether tested in simple tension or under cyclic or creep loading. Failure modes were generally similar in creep rupture and cyclic fatigue tests; no effect of a slack load on each cycle was evident in the failure mode or specimen lifetime.

Diplomová práce se zabývá výpočtovým modelování balistiky odolného laminátu na bázi polyamidových vláken. Úvodní pasáže práce jsou zaměřeny na porozumění jednotlivých problematik, které úzce souvisí s interakcí střely a terče, a výpočtovým modelování tohoto děje. Hlavním cílem práce bylo vytvořit výpočtový model, který je schopen reflektovat chování aramidové tkaniny při interakci se střelou. Během vývoje výpočtového modelu bylo posouzeno více metod modelování a rovněž bylo využito více modelů materiálu. Pro účely vývoje výpočtového modelu bylo využito dostupných dat a experimentů firem SVS FEM s.r.o. a VVÚ s. p. Výsledkem diplomové práce je výpočtový model aramidové tkaniny, který je určen pro simulace balistické ochrany. Tento výpočtový model je validován na základě dostupných experimentů. Validovaný výpočtový model je poté využit pro simulaci balistické ochrany., This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.

Diplomová práce se zabývá výpočtovým modelování balistiky odolného laminátu na bázi polyamidových vláken. Úvodní pasáže práce jsou zaměřeny na porozumění jednotlivých problematik, které úzce souvisí s interakcí střely a terče, a výpočtovým modelování tohoto děje. Hlavním cílem práce bylo vytvořit výpočtový model, který je schopen reflektovat chování aramidové tkaniny při interakci se střelou. Během vývoje výpočtového modelu bylo posouzeno více metod modelování a rovněž bylo využito více modelů materiálu. Pro účely vývoje výpočtového modelu bylo využito dostupných dat a experimentů firem SVS FEM s.r.o. a VVÚ s. p. Výsledkem diplomové práce je výpočtový model aramidové tkaniny, který je určen pro simulace balistické ochrany. Tento výpočtový model je validován na základě dostupných experimentů. Validovaný výpočtový model je poté využit pro simulaci balistické ochrany., This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.

Diplomová práce se zabývá výpočtovým modelování balistiky odolného laminátu na bázi polyamidových vláken. Úvodní pasáže práce jsou zaměřeny na porozumění jednotlivých problematik, které úzce souvisí s interakcí střely a terče, a výpočtovým modelování tohoto děje. Hlavním cílem práce bylo vytvořit výpočtový model, který je schopen reflektovat chování aramidové tkaniny při interakci se střelou. Během vývoje výpočtového modelu bylo posouzeno více metod modelování a rovněž bylo využito více modelů materiálu. Pro účely vývoje výpočtového modelu bylo využito dostupných dat a experimentů firem SVS FEM s.r.o. a VVÚ s. p. Výsledkem diplomové práce je výpočtový model aramidové tkaniny, který je určen pro simulace balistické ochrany. Tento výpočtový model je validován na základě dostupných experimentů. Validovaný výpočtový model je poté využit pro simulaci balistické ochrany., This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.

Diplomová práce se zabývá výpočtovým modelování balistiky odolného laminátu na bázi polyamidových vláken. Úvodní pasáže práce jsou zaměřeny na porozumění jednotlivých problematik, které úzce souvisí s interakcí střely a terče, a výpočtovým modelování tohoto děje. Hlavním cílem práce bylo vytvořit výpočtový model, který je schopen reflektovat chování aramidové tkaniny při interakci se střelou. Během vývoje výpočtového modelu bylo posouzeno více metod modelování a rovněž bylo využito více modelů materiálu. Pro účely vývoje výpočtového modelu bylo využito dostupných dat a experimentů firem SVS FEM s.r.o. a VVÚ s. p. Výsledkem diplomové práce je výpočtový model aramidové tkaniny, který je určen pro simulace balistické ochrany. Tento výpočtový model je validován na základě dostupných experimentů. Validovaný výpočtový model je poté využit pro simulaci balistické ochrany., This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.

Diplomová práce se zabývá výpočtovým modelování balistiky odolného laminátu na bázi polyamidových vláken. Úvodní pasáže práce jsou zaměřeny na porozumění jednotlivých problematik, které úzce souvisí s interakcí střely a terče, a výpočtovým modelování tohoto děje. Hlavním cílem práce bylo vytvořit výpočtový model, který je schopen reflektovat chování aramidové tkaniny při interakci se střelou. Během vývoje výpočtového modelu bylo posouzeno více metod modelování a rovněž bylo využito více modelů materiálu. Pro účely vývoje výpočtového modelu bylo využito dostupných dat a experimentů firem SVS FEM s.r.o. a VVÚ s. p. Výsledkem diplomové práce je výpočtový model aramidové tkaniny, který je určen pro simulace balistické ochrany. Tento výpočtový model je validován na základě dostupných experimentů. Validovaný výpočtový model je poté využit pro simulaci balistické ochrany., This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.

Diplomová práce se zabývá výpočtovým modelování balistiky odolného laminátu na bázi polyamidových vláken. Úvodní pasáže práce jsou zaměřeny na porozumění jednotlivých problematik, které úzce souvisí s interakcí střely a terče, a výpočtovým modelování tohoto děje. Hlavním cílem práce bylo vytvořit výpočtový model, který je schopen reflektovat chování aramidové tkaniny při interakci se střelou. Během vývoje výpočtového modelu bylo posouzeno více metod modelování a rovněž bylo využito více modelů materiálu. Pro účely vývoje výpočtového modelu bylo využito dostupných dat a experimentů firem SVS FEM s.r.o. a VVÚ s. p. Výsledkem diplomové práce je výpočtový model aramidové tkaniny, který je určen pro simulace balistické ochrany. Tento výpočtový model je validován na základě dostupných experimentů. Validovaný výpočtový model je poté využit pro simulaci balistické ochrany., This master thesis is aimed at computational modeling of ballistic resistant layered laminate. The introductory sections of the thesis are aimed at understanding the individual topics that are closely related to the interaction of the projectile and target and computational modeling of this process. The main goal of this thesis was to create a computational model that is able to reflect the behavior of aramid fabric during the interaction with the projectile. During the development of the computational model were used more methods of modeling and also more material models were used. For the purposes of the development of the computational model were used the available data of the companies SVS FEM s.r.o. and VVÚ s.p. The outcome of the diploma thesis is a computational model of aramid fabric which is designed for ballistic protection simulations. This model is validated on the basis of available experiments. The validated computational model is then applied to the simulation of ballistic protection.