The Experts below are selected from a list of 1260 Experts worldwide ranked by ideXlab platform
Yanping Liu - One of the best experts on this subject based on the ideXlab platform.
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finite element modeling of 3d Spacer Fabric effect of the geometric variation and amount of Spacer yarns
Composite Structures, 2020Co-Authors: Yuan Zhang, Yordan Kyosev, Yanping LiuAbstract:Abstract 3D Spacer Fabrics are a type of sandwich structure consisting of two separate multifilament Fabric outer layers linked together with a layer of Spacer monofilaments. They have been widely used as energy absorbing materials and composite reinforcement. The microstructure features and compression behavior of a typical Spacer Fabric were investigated experimentally and numerically in this study. Eight unit cells with 64 Spacer monofilaments were reconstructed from scanning of the Fabric via Micro X-ray computed tomography (μCT). The geometric variations of the reconstructed Spacer monofilaments were analyzed quantitatively. It was found that Spacer monofilaments in different unit cells are different in length, curvature and torsion. A series of FE models based on different numbers and combinations of the identified unit cells were created. The FE simulation results showed that the geometric variations of Spacer monofilaments have strong influence on the compression behavior, and the model with shorter length, lower curvature and torsion of Spacer monofilaments has higher compression resistance. The compression resistance in the densification stage of the Fabric increases with increasing the number of Spacer monofilaments adopted due to more evident interactions among Spacer yarns. This study provides an in-depth understanding on the compression behavior of Spacer Fabric.
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Finite element analysis of compression behaviour of 3D Spacer Fabric structure
International Journal of Mechanical Sciences, 2015Co-Authors: Yanping LiuAbstract:Abstract 3D finite element (FE) analysis was conducted to investigate the mechanical behaviour of a typical 3D Spacer Fabric structure under compression in terms of its structural feature and mechanical properties of its components. A Spacer Fabric consists of two separate outer layers joined together with Spacer monofilaments. Six FE models with different constraints on the Spacer monofilaments and outer layer thicknesses were created using the precise geometry of a unit cell from Micro-X-ray computed tomography (μCT) scanning by fully considering the yarn interactions among all the Fabric components and material׳s nonlinearity. A FE model which could give a satisfactory prediction of the compression load–displacement relationship of the Fabric was employed to identify the compression mechanism. It was confirmed from the simulation that the nonlinear compression behaviour of the 3D Spacer Fabric structure resulted from post-buckling, torsion, shear, rotation and contacts of the Spacer monofilaments as well as the contacts between the Spacer monofilaments and outer layers. It was found from a parametric study that the Spacer Fabric structure made with smaller Spacer monofilament inclination angle, coarser Spacer monofilaments and lower Fabric thickness possesses higher compression resistance.
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Finite element analysis of compression behaviour of 3D Spacer Fabric structure
International Journal of Mechanical Sciences, 2015Co-Authors: Yanping LiuAbstract:3D finite element (FE) analysis was conducted to investigate the mechanical behaviour of a typical 3D Spacer Fabric structure under compression in terms of its structural feature and mechanical properties of its components. A Spacer Fabric consists of two separate outer layers joined together with Spacer monofilaments. Six FE models with different constraints on the Spacer monofilaments and outer layer thicknesses were created using the precise geometry of a unit cell from Micro-X-ray computed tomography (mu CT) scanning by fully considering the yarn interactions among all the Fabric components and material's nonlinearity. A FE model which could give a satisfactory prediction of the compression load-displacement relationship of the Fabric was employed to identify the compression mechanism. It was confirmed from the simulation that the nonlinear compression behaviour of the 3D Spacer Fabric structure resulted from post-buckling, torsion, shear, rotation and contacts of the Spacer monofilaments as well as the contacts between the Spacer monofilaments and outer layers. It was found from a parametric study that the Spacer Fabric structure made with smaller Spacer monofilament inclination angle, coarser Spacer monofilaments and lower Fabric thickness possesses higher compression resistance. (Institute of Textiles and Clothin
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An Experimental Study of Compression Behavior of Warp-knitted Spacer Fabric:
Journal of Engineered Fibers and Fabrics, 2014Co-Authors: Yanping LiuAbstract:This paper presents an experimental study of the compression behavior of a typical warp-knitted Spacer Fabric which is specially developed as a cushioning material for human body protection. The fa...
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protective properties of warp knitted Spacer Fabrics under impact in hemispherical form part i impact behavior analysis of a typical Spacer Fabric
Textile Research Journal, 2014Co-Authors: Yanping LiuAbstract:This paper presents an experimental study of the protective properties of warp-knitted Spacer Fabrics developed for protecting the human body on impact. A drop-weight impact tester was used to test the Fabrics in a hemispherical form to simulate the use of impact protectors in real life. The study consists of two parts. The first part, presented in the current paper, focuses on the impact behavior of a typical Spacer Fabric impacted at different levels of energy. The analysis includes the impact process and the energy absorption and force attenuation properties of the Spacer Fabric. Frequency domain analysis is also used, to identify the different deformation and damage modes of the Fabric under various levels of impact energy. The results show that the impact behavior of the Fabric under impact in the hemispherical form is different from that in the planar form. The results also indicate that the curvature of the Fabric can reduce energy absorption during the impact process and therefore reduce the force attenuation properties of the Spacer Fabric. This study provides a better understanding of the protective properties of Spacer Fabrics. The effect of Fabric structural parameters and lamination on the protective properties of Spacer Fabrics under impact will be presented in Part II.
Jiansheng Guo - One of the best experts on this subject based on the ideXlab platform.
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the design and performance evaluation of a high efficient flexible solar air heater based on transparent Spacer Fabric composite
Solar Energy Materials and Solar Cells, 2019Co-Authors: Jingjing Zhu, Hao Jia, Xiaomei Cheng, Xinyu Huang, Xueyang Liu, Jiansheng GuoAbstract:Abstract In this paper, a novel flexible solar air heater (FSAH) has been rationally designed and fully investigated by practical experiments. The main part of the FSAH is an integrated flexible warp-knitted Spacer Fabric composite, in which Spacer filaments are coated with solar energy absorbing materials by the air spraying method. In this system, flexible Spacer Fabric composite not only works as a solar thermal energy harvesting layer, but also provides airflow channels for energy transmission. By comparison test, it is found that the outlet temperature and thermal efficiency of FSAH were improved by introducing nano-black carbon particles as solar energy absorbing materials coated on the surface of Spacer filaments. An analysis of net energy gain and effective efficiency was then carried out and the best thermohydraulic performance of the as-Fabricated FSAH was found at the mass flow velocity of 0.037 kg m−2 s−1. The optimization experiments demonstrated that with the increase of heater length, the outlet temperature and energy gain of FSAH increased, while their thermal efficiency and effective efficiency decreased. Furthermore, to reduce the heat losses from the top layer to the surrounding ambient, another layer of transparent Spacer Fabric composite was assembled with the FSAH as a thermal insulation layer and its thermal efficiency and effective efficiency were found to be increased by 20%.
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solar thermal energy harvesting properties of Spacer Fabric composite used for transparent insulation materials
Solar Energy Materials and Solar Cells, 2018Co-Authors: Hao Jia, Jingjing Zhu, Dereje Kebebew Debeli, Jiansheng GuoAbstract:Abstract Transparent insulation materials (TIMs) hold an extraordinary potential in solar thermal energy collection, and are gradually and widely applied in the energy-saving buildings. However, due to the limitation of available materials, conventional TIMs are rigid, heavy and uneasy for installation. In this paper, a novel TIM product made of Spacer Fabric composites was designed and investigated experimentally. Compared with traditional TIMs, the proposed Spacer Fabric composites are featured with flexibility, low weight and high applicability. Four different types of Spacer Fabrics composites were developed to analyze the solar energy conversion efficiency using textile material. Their chemical composition, conductivity and water repellency properties were systemically evaluated using UV–VIS–NIR, thermal detector and contact angle measurements. The Spacer Fabric composites of Spacer filament in ‘X’ type was demonstrated to have a stronger solar thermal collection capacity than that of ‘V’ type. Also, the poly-p-xylene coating contributed to a higher thermal insulation and stronger water repellency property. To be specific, the stable collection temperature of the optimal composites can reach to 98 °C from the ambient temperature of 32 °C at a radiation of 1100 W/m 2 . In conclusion, the Spacer Fabric composites demonstrated to have large potential and extremely broad application prospect in the field of transparent insulation materials.
Hairu Long - One of the best experts on this subject based on the ideXlab platform.
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sound absorption properties of polyurethane based warp knitted Spacer Fabric composites
Indian Journal of Fibre & Textile Research (IJFTR), 2017Co-Authors: Si Chen, Hong-xia Chen, Xiao-ping Gao, Hairu LongAbstract:Sound absorption properties of polyurethane-based warp-knitted Spacer Fabric composites (PWSF) have been studied. The warp-knitted Spacer Fabrics (WSF) are produced on a double-needle bar warp knitting machine using different structural parameters including inclination angle of Spacer yarn, thickness, Spacer yarn’s diameter and surface layer structure. The composites are Fabricated based on a flexible polyurethane foam. Accordingly, the acoustical behaviors of composites are evaluated properly by using two-microphone transfer function techniques in impedance tube. The findings reveal that the composites possess excellent sound absorption properties and their sound absorbability can be tailored to meet the specific end-use requirements by varying the Fabric structural parameters.
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low velocity impact properties and finite element analysis of syntactic foam reinforced by warp knitted Spacer Fabric
Textile Research Journal, 2017Co-Authors: Chao Zhi, Hairu Long, Fengxin SunAbstract:The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted Spacer Fabric (SF-WKSF). In order to discuss the effect of warp-knitted Spacer Fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were Fabricated, including different WKSF surface layer structures, different Spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the Spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a...
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compressive properties of syntactic foam reinforced by warp knitted Spacer Fabric
Cellular Polymers, 2015Co-Authors: Chao Zhi, Hairu LongAbstract:Syntactic foam composites are widely used as aviation, construction and marine materials because of their high specific strength, specific modulus, damage tolerance and low moisture absorption. The...
Chao Zhi - One of the best experts on this subject based on the ideXlab platform.
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low velocity impact properties and finite element analysis of syntactic foam reinforced by warp knitted Spacer Fabric
Textile Research Journal, 2017Co-Authors: Chao Zhi, Hairu Long, Fengxin SunAbstract:The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted Spacer Fabric (SF-WKSF). In order to discuss the effect of warp-knitted Spacer Fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were Fabricated, including different WKSF surface layer structures, different Spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the Spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a...
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compressive properties of syntactic foam reinforced by warp knitted Spacer Fabric
Cellular Polymers, 2015Co-Authors: Chao Zhi, Hairu LongAbstract:Syntactic foam composites are widely used as aviation, construction and marine materials because of their high specific strength, specific modulus, damage tolerance and low moisture absorption. The...
T Dias - One of the best experts on this subject based on the ideXlab platform.
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analysis of physical properties and structure design of weft knitted Spacer Fabric with high porosity
Textile Research Journal, 2018Co-Authors: Chaoyu Chen, Zhaoqun Du, Weidong Yu, T DiasAbstract:The main content dealt with in the paper is to present a kind of weft-knitted Spacer Fabric with high porosity. It is a kind of three-dimensional textile Fabric with a sandwich structure that consi...
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analysis of thick Spacer Fabrics to reduce automobile interior noise
Measurement Science and Technology, 2007Co-Authors: T Dias, Ravindra MonaragalaAbstract:Textile structures have the potential to reduce interior noise in an automobile; here the sound absorption of a novel knitted Spacer Fabric is discussed. The Spacer Fabric was analysed as a micro perforated panel absorber, a simulation being carried out on the effect of the structural properties of the Fabric on its sound absorption capability. This mathematical analysis was then validated by suitably knitted Spacer Fabric samples. The results show a significant improvement in sound absorption compared to planar knitted structures.
