scholarly journals Influence of Water-Induced Degradation of Polytetrafluoroethylene (PTFE)-Coated Woven Fabrics Mechanical Properties

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 1
Author(s):  
Andrzej Ambroziak ◽  
Paweł Kłosowski

The impact of water-induced degradation on the mechanical properties of the chosen two PTFE-coated, glass threads woven fabrics is investigated in this paper. The paper begins with a survey of literature concerning the investigation and determination of coated woven fabric properties. The authors carried out the uniaxial tensile tests with an application of flat and curved grips to establish the proper values of the ultimate tensile strength and the longitudinal stiffness of groups of specimens treated with different moisture conditions. Despite the water resistance of the main materials used for fabrics manufacturing, the change of the mechanical properties caused by the influence of water immersion has been noticed. The reduction in the tensile strength resulting under waterlogged is observed in the range from 5% to 16% depending on the type of investigated coated woven fabric and direction of weft or warp.

2015 ◽  
Vol 35 (4) ◽  
pp. 377-390 ◽  
Author(s):  
Andrzej Ambroziak

Abstract This article describes the laboratory tests necessary to identify the mechanical properties of the polyvinylidene fluoride (PVDF)-coated fabrics named Precontraint 1202S and Precontraint 1302S. First, a short survey of the literature concerning the description of coated woven fabrics is presented. Second, the material parameters for PVDF-coated fabrics are specified on the basis of biaxial tensile tests. A comparison of the 1:1 biaxial and the uniaxial tensile tests results is also given. Additionally, biaxial cyclic tests were performed to observe the change of immediate mechanical properties under cyclic load. The article is aimed as an introduction to a comprehensive investigation of the mechanical properties of coated fabrics.


2021 ◽  
Author(s):  
Budi Arifvianto ◽  
Teguh Nur Iman ◽  
Benidiktus Tulung Prayoga ◽  
Rini Dharmastiti ◽  
Urip Agus Salim ◽  
...  

Abstract Fused filament fabrication (FFF) has become one of the most popular, practical, and low-cost additive manufacturing techniques for fabricating geometrically-complex thermoplastic polyurethane (TPU) elastomer. However, there are still some uncertainties concerning the relationship between several operating parameters applied in this technique and the mechanical properties of the processed material. In this research, the influences of extruder temperature and raster orientation on the mechanical properties of the FFF-processed TPU elastomer were studied. A series of uniaxial tensile tests was carried out to determine tensile strength, strain, and elastic modulus of TPU elastomer that had been printed with various extruder temperatures, i.e., 190–230 °C, and raster angles, i.e., 0–90°. Thermal and chemical characterizations were also conducted to support the analysis in this research. The results obviously showed the ductile and elastic characteristics of the FFF-processed TPU, with specific tensile strength and strain that could reach up to 39 MPa and 600%, respectively. The failure mechanisms operating on the FFF-processed TPU and the result of stress analysis by using the developed Mohr’s circle are also discussed in this paper. In conclusion, the extrusion temperature of 200 °C and raster angle of 0° could be preferred to be applied in the FFF process to achieve high strength and ductile TPU elastomer.


2000 ◽  
Vol 9 (3) ◽  
pp. 096369350000900 ◽  
Author(s):  
J.L. Billoet ◽  
A. Cherouat

The present study concerns the modelling of the behaviour of pre-impregnated woven fabric during the forming process. The mechanical approach is based on a mesostructural model. It allows us to take into account the mechanical properties of fibres and resin and the various dominating mode of deformation of woven fabrics during the forming process. Shear and tensile tests of composite fabric specimens are proposed and compared with the experimental results in order to demonstrate the efficiency of our approach. Different numerical simulations and experiments of shaping process have been carried out in order to validate the proposed computational formulation. The various forming parameters examined have included the initial shape of fabric, fibre orientations and viscosity of resin.


2016 ◽  
Vol 36 (4) ◽  
pp. 254-270 ◽  
Author(s):  
Andrzej Ambroziak ◽  
Paweł Kłosowski

The purpose of the paper is the estimation of the polyvinyl chloride – polyester-coated fabric (Precontraint 1202 S2) mechanical properties under uniaxial tensile tests as well as short- and long-time creep tests. The uniaxial tests are the basis of non-linear elastic description while the creep tests are used for the evaluation of the stiffness parameters in time and for the identification of the standard viscoelastic model. The paper also includes a short survey of literature concerning the coated woven fabric description.


Author(s):  
Jagannathan Sankar ◽  
Jayant Neogi ◽  
Suneeta S. Neogi ◽  
Marvln T. Dixie ◽  
Ranji Vaidyanathan

The effect of thermal soaking on the mechanical properties of a candidate material for advanced heat engine applications namely, hot isostatically pressed (HIPed) silicon nitride (GTEPY6) are reported here. Pure uniaxial tensile tests conducted at room and at elevated temperatures indicated that the tensile strength of this material dropped significantly after 1000°C. The residual tensile strength of PY6 material after thermal soaking at 1200° and 1300°C was also investigated. Test results showed that thermal soaking at 1200° and 1300°C increased the residual tensile strength. The thermal soaking time had a greater effect on the residual tensile strength at 1300°C. Tensile creep tests performed at 1200° and 1300°C showed that the steady state creep rate was influenced by both the temperature and the applied stress. The higher stress exponent in HIPed as compared to a sintered silicon nitride shows higher creep resistance in the case of HIPed materials.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Lanlan Zhang

Two types of Precontraint PVDF coated polyester are taken as the research objects. A series of uniaxial tensile tests were carried out to study the tensile performances of the specimens in eleven in-plane directions including 0°, 5°, 15°, 25°, 35°, 45°, 55°, 65°, 75°, 85°, and 90°, and six tensile rates (10 mm/min, 25 mm/min, 50 mm/min, 100 mm/min, 200 mm/min, and 500 mm/min) were also considered. The corresponding failure modes and fracture mechanisms were discussed, and the relationships between tensile strength and strain at break and tensile rate and off-axial angles were obtained. Results show that the Precontraint PVDF coated woven fabrics are typically anisotropic. With off-axial angle increasing, the tensile strength decreases while the strain at break increases. Three failure modes can be observed, including failure of yarns pulled out, yarns fracture, and mixture failure. With tensile rate increasing, the tensile strength increases slightly while the strain at break decreases. The tensile strength and strain at break show good linear relationship with tensile rate’s logarithm.


Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 381
Author(s):  
Dongsheng Qian ◽  
Yuangeng He ◽  
Feng Wang ◽  
Yun Chen ◽  
Xiaohui Lu

The microstructure and mechanical properties of M50 steel subjected to combining cold rolling (CR) with austempering are investigated. The microstructure is characterized using X-ray diffraction and scanning and transmission electron microscopy. The mechanical properties are measured using the uniaxial tensile and Charpy impact tests. It is observed that an excellent combination of ultimate tensile strength (2536 MPa) and impact toughness (128 J) was achieved by combining austempering with CR; of which the ultimate tensile strength increased by 10% compared with traditional martensite quenching-tempering (Q-T) specimen and the impact absorbed energy exhibited 2.3 times of that in Q-T specimen. The observation of the microstructure indicates that CR obviously refines the thickness of bainite sheaves, which is favorable for the formation of ultrafine equiaxed ferrite during tempering.


2008 ◽  
Vol 75 (1) ◽  
Author(s):  
J. H. Kim ◽  
N. Brandenburg ◽  
W. McDonough ◽  
W. Blair ◽  
G. A. Holmes

A device was designed and built that attaches to servohydraulic machines that typically perform material fatigue testing. The device was designed to systematically fold woven fabric and yarns of ballistic fibers to assess the impact of mechanical folding, such as may occur during use, on ballistic fiber properties. Initial tests indicate that the device repeatedly folds a piece of woven fabric at the same location. However, when the device is in the open position, a consistent 1cm movement of the fabric was observed. A slight modification of the device is required to eliminate this movement. After cycling a piece of woven poly(benzoxazole) (PBO) fabric for 5500 cycles, an 18% reduction in the ultimate tensile strength and strain to failure of the PBO fibers was observed. Research is continuing to determine a relevant and optimized testing protocol.


2021 ◽  
Vol 1016 ◽  
pp. 399-406
Author(s):  
Christoph Egger ◽  
Florian Grünbart ◽  
Zahra Silvayeh ◽  
Olga Šulcová ◽  
Christoph Seper ◽  
...  

Fabrication of aluminum alloy components by traditional high-pressure die casting (HPDC) requires cost- and time-consuming tooling of steel dies, which makes HPDC uneconomic for producing low-volume components or prototypes. In comparison, powder bed-based additive manufacturing, e.g. selective laser melting (SLM), enables rapid prototyping and production of even complex-shaped components directly from computer-aided design models without needing expensive tools. However, SLM prototype components must have almost identical mechanical properties to HPDC serial components in order to emulate their functionality under different load conditions. In this work uniaxial tensile properties of cast alloy AlSi10MnMg (EN AC-43500) in condition T7, i.e. with 120-170 MPa yield stress, 200-240 MPa tensile strength and 9-12 % strain at fracture, shall be attained using selective laser melting of powder alloy AlSi10Mg (EN AC-43000). These properties were achieved by tailored heat treatment. Furthermore, the effect of hot isostatic pressing (HIP) was investigated. The results of the tensile tests confirmed the basic feasibility of substituting HPDC components with SLM components for prototyping. In particular, similar tensile strength and uniform strain were achieved for SLM samples in condition O, i.e. for SLM samples which were only annealed.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1671
Author(s):  
Mohd Shahneel Saharudin ◽  
Jiri Hajnys ◽  
Tomasz Kozior ◽  
Damian Gogolewski ◽  
Paweł Zmarzły

The paper presents the results of mechanical tests of models manufactured with two 3D printing technologies, FDM and CFF. Both technologies use PLA or PA-based materials reinforced with carbon fibers. The work includes both uniaxial tensile tests of the tested materials and metrological measurements of surfaces produced with two 3D printing technologies. The test results showed a significant influence of the type of technology on the strength of the models built and on the quality of the technological surface layer. After the analysis of the parameters of the primary profile, roughness and waviness, it can be clearly stated that the quality of the technological surface layer is much better for the models made with the CFF technology compared to the FDM technology. Furthermore, the tensile strength of the models manufactured of carbon fiber-enriched material is much higher for samples made with CFF technology compared to FDM.


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