Communications in Development and Assembling of Textile Products
For a holistic assessment of the interaction between the human body and tight fitted clothing, it... more For a holistic assessment of the interaction between the human body and tight fitted clothing, it is necessary to consider the mechanical properties of the body. Default avatars in CAD software are usually solid and do not take this interaction into account. For this purpose, a solid avatar is converted to a deformable one by using the soft body physics implementation in the simulation program Blender. The fit of a 3D garment on both avatars are compared, which allows a first evaluation of the differences between these approaches.
A stab resistant vest is a reinforced piece of body armour designed to resist knife or needle att... more A stab resistant vest is a reinforced piece of body armour designed to resist knife or needle attacks of different energy levels specifically to the upper part of the body (chest and abdomen) to save lives. The majority of armours limit several comfort parameters, such as free locomotion, respiration, flexibility and light weight, which determine efficient use by wearers and their willingness to wear. Currently available armours are usually made of a single plate, and although often segmentation is used with just a few but still quite large pieces, the materials are compact and bulky to wear. In this study, stab protective armor elements (scale-like elements) of 3 mm thickness and 50 mm diameter were designed, produced (3D printed) and tested for performance. Aramid fibre was used for its strength, durability and process ability to develop protection elements at unidirectional and multidirectional filling angles during 3D printing. The specimens were tested according to VPAM KDIW 20...
1. 3D coordinates of the 64 spacer monofilaments. The first, second, and third columns are x, y, ... more 1. 3D coordinates of the 64 spacer monofilaments. The first, second, and third columns are x, y, and z-axis, respectively. 2. line to line contact coordinates.
International Symposium "Technical Textiles - Present and Future", 2022
Non-woven fabrics are widely used in technical textiles applications and functional clothing. The... more Non-woven fabrics are widely used in technical textiles applications and functional clothing. The geometrical model of non-woven structures for special clothing is the significant start point for simulating their properties. This paper demonstrates the application of the statistical fiber-based geometrical method, which can be used to build the non-woven microstructure with high accuracy. The method consists of three steps. The first step is the detection and analysis of the fiber orientation and coordinates. The coordinates of each analysed fiber are recorded using image processing software (IMAGE J) from the scanning electron microscope pictures of the non-woven structures. The second step is the development of a mathematical model which describes the coordinates the orientation of the fiber line and the deviation of its distance between the line. For the last step-3D representation-these coordinates are extended with the third space coordinate using python script and finally visualized using 3D view software (TexMind Textile Viewer). Generated nonwoven modules were satisfactory compared qualitatively as well as quantitatively against the accurate scanning electronic microscope pictures of the non-woven fabrics and can be performed as fundamental point for advanced mechanical, thermal, electric, and other simulations.
Using a lapped seam, PVC-coated hybrid textiles with uniform thickness were bonded by continuous ... more Using a lapped seam, PVC-coated hybrid textiles with uniform thickness were bonded by continuous ultrasonic welding and conventional joining method with the help of hot air tape welding technique for weather protection purposes. Three fundamental sewing parameters at two distinct levels and three primary welding parameters at three levels based on 6 and 12 mm welding widths were used. To consider the effect of welding and sewing parameters on seam strength, full factorial designs of experiments were designed, fabricated, and tested. The thermal behavior and possibility of chemical conversion in the welding zone under the influence of ultrasonic vibrations were examined. Variation in width of heat-affected zone of weld seam was measured. The seam strength of ultrasonic weld seam compared with that of conventional seams, and superior seam strength yielding parametric levels were assessed. The parametric influence of both joining techniques on seam quality and their tendencies in the r...
In this study, the mechanical response of braided composite tube under three points bending loadi... more In this study, the mechanical response of braided composite tube under three points bending loading was studied by experimental and numerical method. Various reinforcements with different bundle orientation indicated by braiding angle were fabricated using over-braiding technology and then cured into composite tubes in a VARTM process. A series of three-point bending tests were performed to examine the damage process and extent from initiation to complete failure. Two distinct failure modes in terms of top surface failure characterized by the debonding between matrix and fabric and rear surface failure characterized by penetrating crack of resin were observed, which consequently leads to different mechanical response. The experimental data indicated that the higher strength can be achieved by increasing the braiding angle, which also increases the tendency to the bottom surface failure.
Many users relate additive manufacturing (AM) directly with fast and high-quality prototyping and... more Many users relate additive manufacturing (AM) directly with fast and high-quality prototyping and manufacturing. Nevertheless, already within the different printing techniques there are significant printing time differences for the same polymer printed objects. For AM, there are currently two main known methods to three-dimensional (3D) print objects: One is the vat polymerization process using liquid crystal display (LCD) polymerization, also known as masked stereolithography (MSLA). The other is material extrusion, known as fused filament fabrication (FFF) or fused deposition modeling. Both processes can be found in the private sector (desktop printers) or in industry. The FFF and MSLA processes apply material layer by layer to 3D print objects, but both processes are different in their printing techniques. The different printing methods result in different printing speeds for the same 3D printed object. Geometry models are used to investigate which design elements affect the printing speed without changing the actual printing parameters. Support and infill are also taken into account. The influencing factors will be shown to optimize the printing time. With the assistance of the different slicer software, the influence factors were calculated and the different variants are pointed out. The determined correlations help to find the suitable printing technique to make optimum use of the printing performance of both technologies.
Generating human finite element models for mechanical or thermal simulations is a complex task. M... more Generating human finite element models for mechanical or thermal simulations is a complex task. Modern 3D scanning technology offers a fast method of capturing the surface of the human body and thus forms the starting point for the future creation of individual FEM models based on the 3D scan. This paper presents some frequently occurring issues and problems in mesh processing, which have often to be solved and which has to be implemented in an automatic procedure for human modelling.
The textile yarns are often modelled as tubes for simplicity, but in the reality the yarns have t... more The textile yarns are often modelled as tubes for simplicity, but in the reality the yarns have their internal fiber based structure. This chapter presents a method for filing the yarn volume with predefined set of filaments, following the yarn axis. The natural twist of the curve is indepenent from the textile related twist, which has to be considered during the sweeping the cross section. Another point is the way of the interpolation of the yarn axis between the key points. Discussed are the advantages and drawbacks of generalized parametric modelling and of the exact function description of the curves between each two points.
In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkret... more In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkrete Aufgabenstellung während des COVID-Semesters in den Jahren 2020 und 2021 vorgestellt. Die Montage von flexiblen Materialien beinhaltet viele manuelle Tätigkeiten, die bisher von den Studierenden während der Praktika selbst durchgeführt werden konnten. Gezeigt werden zwei Aufgaben zur Online-Unterstützung der Lehre durch die Programmierung einer 3D-Visualisierung der Stichtypen und der Dokumentation der Montagevorgänge durch Video oder Bild- und Textreihen. Die Erfahrungen zeigten, dass diese Visualisierungsvarianten den Personalaufwand etwas reduzieren können, aber das Mitführen eines Abspielgerätes (Tablet) von jedem Studenten während des Praktikums erfordern. Die Erfahrungen aus den beiden Aufgaben sollen auch für die Zukunft genutzt werden, um den Studenten mehr eigenständige Aufgaben anzubieten.
Since the arrival of electronics in the textile field, the ribbon transformed into e-ribbon inaug... more Since the arrival of electronics in the textile field, the ribbon transformed into e-ribbon inaugurates its functionalities with two unseen features in hand: it joins together physically and electronically different worlds, arriving to the transformation of itself into an electronical component, in other words, materializing the service. The e-garments, as well as e-ribbons, intimately ally esthetics with utility. Halfway between product design and fashion, it is obliged to integrate the end user’s opinion and think about new services to offer to the digital world. Going from connectivity through clients support and new marketing strategies, E-ribbons are getting their way in shaking the secular habits of a dynamic field, and yet, a linear one. The narrow textiles have a pioneer and strategic role to play NOW.
Topology-Based Modeling of Textile Structures and Their Joint Assemblies
Sewing stitches are used to connect two or more textile structures. Their modelling is required a... more Sewing stitches are used to connect two or more textile structures. Their modelling is required at the places, where the yarn level model has to contain all elements. This chapter represent the topological rules for modelling the main types of stitches. Considerations about the number of keypoints and the type of the interpolation of the curve between these are given.
In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkret... more In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkrete Aufgabenstellung während des COVID-Semesters in den Jahren 2020 und 2021 vorgestellt. Die Montage von flexiblen Materialien beinhaltet viele manuelle Tätigkeiten, die bisher von den Studierenden während der Praktika selbst durchgeführt werden konnten. Gezeigt werden zwei Aufgaben zur Online-Unterstützung der Lehre durch die Programmierung einer 3D-Visualisierung der Stichtypen und der Dokumentation der Montagevorgänge durch Video oder Bildund Textreihen. Die Erfahrungen zeigten, dass diese Visualisierungsvarianten den Personalaufwand etwas reduzieren können, aber das Mitführen eines Abspielgerätes (Tablet) von jedem Studenten während des Praktikums erfordern. Die Erfahrungen aus den beiden Aufgaben sollen auch für die Zukunft genutzt werden, um den Studenten mehr eigenständige Aufgaben anzubieten. This paper presents an experience report on the implementation of online teaching and a c...
Topology-Based Modeling of Textile Structures and Their Joint Assemblies, 2018
This chapter presents the fundamental approach of the description of the yarn paths in weft and w... more This chapter presents the fundamental approach of the description of the yarn paths in weft and warp knitted structures using selected key points. For most of the common structural elements, rules for calculation of the coordinates of their key points are defined, depending on the size of the loop, yarn and depending on the neighbor elements. Some problems and disadvantages of the method for specific elements are described. The approach builds the theoretical core of the modern CAD systems for 3D representation of knitted structures. Its efficiency is proven by its implementation in professional software.
Communications in Development and Assembling of Textile Products
For a holistic assessment of the interaction between the human body and tight fitted clothing, it... more For a holistic assessment of the interaction between the human body and tight fitted clothing, it is necessary to consider the mechanical properties of the body. Default avatars in CAD software are usually solid and do not take this interaction into account. For this purpose, a solid avatar is converted to a deformable one by using the soft body physics implementation in the simulation program Blender. The fit of a 3D garment on both avatars are compared, which allows a first evaluation of the differences between these approaches.
A stab resistant vest is a reinforced piece of body armour designed to resist knife or needle att... more A stab resistant vest is a reinforced piece of body armour designed to resist knife or needle attacks of different energy levels specifically to the upper part of the body (chest and abdomen) to save lives. The majority of armours limit several comfort parameters, such as free locomotion, respiration, flexibility and light weight, which determine efficient use by wearers and their willingness to wear. Currently available armours are usually made of a single plate, and although often segmentation is used with just a few but still quite large pieces, the materials are compact and bulky to wear. In this study, stab protective armor elements (scale-like elements) of 3 mm thickness and 50 mm diameter were designed, produced (3D printed) and tested for performance. Aramid fibre was used for its strength, durability and process ability to develop protection elements at unidirectional and multidirectional filling angles during 3D printing. The specimens were tested according to VPAM KDIW 20...
1. 3D coordinates of the 64 spacer monofilaments. The first, second, and third columns are x, y, ... more 1. 3D coordinates of the 64 spacer monofilaments. The first, second, and third columns are x, y, and z-axis, respectively. 2. line to line contact coordinates.
International Symposium "Technical Textiles - Present and Future", 2022
Non-woven fabrics are widely used in technical textiles applications and functional clothing. The... more Non-woven fabrics are widely used in technical textiles applications and functional clothing. The geometrical model of non-woven structures for special clothing is the significant start point for simulating their properties. This paper demonstrates the application of the statistical fiber-based geometrical method, which can be used to build the non-woven microstructure with high accuracy. The method consists of three steps. The first step is the detection and analysis of the fiber orientation and coordinates. The coordinates of each analysed fiber are recorded using image processing software (IMAGE J) from the scanning electron microscope pictures of the non-woven structures. The second step is the development of a mathematical model which describes the coordinates the orientation of the fiber line and the deviation of its distance between the line. For the last step-3D representation-these coordinates are extended with the third space coordinate using python script and finally visualized using 3D view software (TexMind Textile Viewer). Generated nonwoven modules were satisfactory compared qualitatively as well as quantitatively against the accurate scanning electronic microscope pictures of the non-woven fabrics and can be performed as fundamental point for advanced mechanical, thermal, electric, and other simulations.
Using a lapped seam, PVC-coated hybrid textiles with uniform thickness were bonded by continuous ... more Using a lapped seam, PVC-coated hybrid textiles with uniform thickness were bonded by continuous ultrasonic welding and conventional joining method with the help of hot air tape welding technique for weather protection purposes. Three fundamental sewing parameters at two distinct levels and three primary welding parameters at three levels based on 6 and 12 mm welding widths were used. To consider the effect of welding and sewing parameters on seam strength, full factorial designs of experiments were designed, fabricated, and tested. The thermal behavior and possibility of chemical conversion in the welding zone under the influence of ultrasonic vibrations were examined. Variation in width of heat-affected zone of weld seam was measured. The seam strength of ultrasonic weld seam compared with that of conventional seams, and superior seam strength yielding parametric levels were assessed. The parametric influence of both joining techniques on seam quality and their tendencies in the r...
In this study, the mechanical response of braided composite tube under three points bending loadi... more In this study, the mechanical response of braided composite tube under three points bending loading was studied by experimental and numerical method. Various reinforcements with different bundle orientation indicated by braiding angle were fabricated using over-braiding technology and then cured into composite tubes in a VARTM process. A series of three-point bending tests were performed to examine the damage process and extent from initiation to complete failure. Two distinct failure modes in terms of top surface failure characterized by the debonding between matrix and fabric and rear surface failure characterized by penetrating crack of resin were observed, which consequently leads to different mechanical response. The experimental data indicated that the higher strength can be achieved by increasing the braiding angle, which also increases the tendency to the bottom surface failure.
Many users relate additive manufacturing (AM) directly with fast and high-quality prototyping and... more Many users relate additive manufacturing (AM) directly with fast and high-quality prototyping and manufacturing. Nevertheless, already within the different printing techniques there are significant printing time differences for the same polymer printed objects. For AM, there are currently two main known methods to three-dimensional (3D) print objects: One is the vat polymerization process using liquid crystal display (LCD) polymerization, also known as masked stereolithography (MSLA). The other is material extrusion, known as fused filament fabrication (FFF) or fused deposition modeling. Both processes can be found in the private sector (desktop printers) or in industry. The FFF and MSLA processes apply material layer by layer to 3D print objects, but both processes are different in their printing techniques. The different printing methods result in different printing speeds for the same 3D printed object. Geometry models are used to investigate which design elements affect the printing speed without changing the actual printing parameters. Support and infill are also taken into account. The influencing factors will be shown to optimize the printing time. With the assistance of the different slicer software, the influence factors were calculated and the different variants are pointed out. The determined correlations help to find the suitable printing technique to make optimum use of the printing performance of both technologies.
Generating human finite element models for mechanical or thermal simulations is a complex task. M... more Generating human finite element models for mechanical or thermal simulations is a complex task. Modern 3D scanning technology offers a fast method of capturing the surface of the human body and thus forms the starting point for the future creation of individual FEM models based on the 3D scan. This paper presents some frequently occurring issues and problems in mesh processing, which have often to be solved and which has to be implemented in an automatic procedure for human modelling.
The textile yarns are often modelled as tubes for simplicity, but in the reality the yarns have t... more The textile yarns are often modelled as tubes for simplicity, but in the reality the yarns have their internal fiber based structure. This chapter presents a method for filing the yarn volume with predefined set of filaments, following the yarn axis. The natural twist of the curve is indepenent from the textile related twist, which has to be considered during the sweeping the cross section. Another point is the way of the interpolation of the yarn axis between the key points. Discussed are the advantages and drawbacks of generalized parametric modelling and of the exact function description of the curves between each two points.
In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkret... more In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkrete Aufgabenstellung während des COVID-Semesters in den Jahren 2020 und 2021 vorgestellt. Die Montage von flexiblen Materialien beinhaltet viele manuelle Tätigkeiten, die bisher von den Studierenden während der Praktika selbst durchgeführt werden konnten. Gezeigt werden zwei Aufgaben zur Online-Unterstützung der Lehre durch die Programmierung einer 3D-Visualisierung der Stichtypen und der Dokumentation der Montagevorgänge durch Video oder Bild- und Textreihen. Die Erfahrungen zeigten, dass diese Visualisierungsvarianten den Personalaufwand etwas reduzieren können, aber das Mitführen eines Abspielgerätes (Tablet) von jedem Studenten während des Praktikums erfordern. Die Erfahrungen aus den beiden Aufgaben sollen auch für die Zukunft genutzt werden, um den Studenten mehr eigenständige Aufgaben anzubieten.
Since the arrival of electronics in the textile field, the ribbon transformed into e-ribbon inaug... more Since the arrival of electronics in the textile field, the ribbon transformed into e-ribbon inaugurates its functionalities with two unseen features in hand: it joins together physically and electronically different worlds, arriving to the transformation of itself into an electronical component, in other words, materializing the service. The e-garments, as well as e-ribbons, intimately ally esthetics with utility. Halfway between product design and fashion, it is obliged to integrate the end user’s opinion and think about new services to offer to the digital world. Going from connectivity through clients support and new marketing strategies, E-ribbons are getting their way in shaking the secular habits of a dynamic field, and yet, a linear one. The narrow textiles have a pioneer and strategic role to play NOW.
Topology-Based Modeling of Textile Structures and Their Joint Assemblies
Sewing stitches are used to connect two or more textile structures. Their modelling is required a... more Sewing stitches are used to connect two or more textile structures. Their modelling is required at the places, where the yarn level model has to contain all elements. This chapter represent the topological rules for modelling the main types of stitches. Considerations about the number of keypoints and the type of the interpolation of the curve between these are given.
In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkret... more In diesem Beitrag wird ein Erfahrungsbericht über die Umsetzung der Online-Lehre und eine konkrete Aufgabenstellung während des COVID-Semesters in den Jahren 2020 und 2021 vorgestellt. Die Montage von flexiblen Materialien beinhaltet viele manuelle Tätigkeiten, die bisher von den Studierenden während der Praktika selbst durchgeführt werden konnten. Gezeigt werden zwei Aufgaben zur Online-Unterstützung der Lehre durch die Programmierung einer 3D-Visualisierung der Stichtypen und der Dokumentation der Montagevorgänge durch Video oder Bildund Textreihen. Die Erfahrungen zeigten, dass diese Visualisierungsvarianten den Personalaufwand etwas reduzieren können, aber das Mitführen eines Abspielgerätes (Tablet) von jedem Studenten während des Praktikums erfordern. Die Erfahrungen aus den beiden Aufgaben sollen auch für die Zukunft genutzt werden, um den Studenten mehr eigenständige Aufgaben anzubieten. This paper presents an experience report on the implementation of online teaching and a c...
Topology-Based Modeling of Textile Structures and Their Joint Assemblies, 2018
This chapter presents the fundamental approach of the description of the yarn paths in weft and w... more This chapter presents the fundamental approach of the description of the yarn paths in weft and warp knitted structures using selected key points. For most of the common structural elements, rules for calculation of the coordinates of their key points are defined, depending on the size of the loop, yarn and depending on the neighbor elements. Some problems and disadvantages of the method for specific elements are described. The approach builds the theoretical core of the modern CAD systems for 3D representation of knitted structures. Its efficiency is proven by its implementation in professional software.
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Papers by Yordan Kyosev