scholarly journals Mechanical Properties of Polypropylene Warp-Knitted Hernia Repair Mesh with Different Pull Densities

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1322
Author(s):  
Wanli Xu ◽  
Pibo Ma ◽  
Gaoming Jiang ◽  
Ailan Wan
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
High Speed ◽  
Vertical Direction ◽  
Horizontal Stress ◽  
Raw Material ◽  
Knitted Fabrics ◽  
Polypropylene Monofilament ◽  
Set Up ◽  
Warp Knitted Fabric

The medical polypropylene monofilament with a diameter of 0.10 mm was used as the material. Four different pull densities and two different warp run-ins were set up on the electronic traverse high-speed Tricot warp knitting machine, with the gauge of E28. The raw material was used to knit four variations of single bar plain knitted fabrics with 1 in-1 miss setting. Each variation required eight samples. The mechanical properties of the above 32 warp-knitted fabric samples are tested, including their tensile stress (in both vertical and horizontal directions), tearing stress (in both vertical and horizontal directions) and bursting stress. The results obtained shows that the relationship between the vertical, the horizontal stress, and the pull density are not monotonic. The tensile stress in the vertical direction firstly decreases and then increases with an increase of the pull density; however, the tensile stress in the horizontal direction firstly increases and then slightly decreases with an increase of the pull density; again the vertical tensile stress of all fabrics was always higher than the horizontal tensile stress. The bursting stress has a positive linear relation to the pull density. The vertical tearing stresses of four samples were greater than the horizontal tearing stress.

MECHANICAL PROPERTIES OF ROTATIONALLY MOLDED PET MICROFIBRIL REINFORCED COMPOSITES

2006 ◽  
Vol 20 (25n27) ◽  
pp. 4613-4618 ◽  
Author(s):  
R. J. T. LIN ◽  
D. BHATTACHARYYA ◽  
S. FAKIROV
Keyword(s):  
Mechanical Properties ◽  
Manufacturing Industry ◽  
Polymer Processing ◽  
Raw Material ◽  
Medium Density ◽  
Reinforced Composites ◽  
Rotational Molding ◽  
Commercial Scale ◽  
Strength And Stiffness ◽  
Set Up

Being a fast growing plastic manufacturing industry, rotational molding has been using the linear polyethylenes extensively as the raw material. As these materials have shown insufficient mechanical properties for certain applications where strength and stiffness of the products are the main concerns, worldwide rotational molders have expressed a need for stronger and stiffer materials to be available for rotomolding. A possible attractive solution may be the recently developed microfibril reinforced composites (MFCs). Blends of linear medium density polyethylene/polyethylene terephthalate (LMDPE/PET) with an MFC structure are manufactured on a commercial-scale set-up and thereafter used in rotational molding. The samples are characterized morphologically and tested mechanically. The results obtained show that the MFC-concept has good application opportunities in the polymer processing including rotational molding.

The Axial Warp-Knitted Fabric and its Reinforced Composite

2011 ◽  
Vol 332-334 ◽  
pp. 837-840
Author(s):  
Yi Hua Bu ◽  
Yan Feng ◽  
Hua Wu Liu
Keyword(s):  
Mechanical Properties ◽  
Woven Fabrics ◽  
Advanced Materials ◽  
Knitted Fabric ◽  
Knitted Fabrics ◽  
Unique Structure ◽  
Reinforced Composite ◽  
And Performance ◽  
Warp Knitted Fabric ◽  
Composite Reinforcement

The structure and performance of the axial warp-knitted composite were introduced, including bi-axial and multi-axial organizations. According to the unique structure of this fabric, the mechanical properties and the advantages as a composite reinforcement were compared with regular staple woven fabrics. The advantages of composites reinforced by bi-axial and multi-axial knitted fabrics were discussed and the applications of such advanced materials were briefly presented.

Improvement in Mechanical Properties of Clay Filled Carbon-Epoxy Composite

2006 ◽  
Author(s):  
Yuanxin Zhou ◽  
Farhana Pervin ◽  
Jamese Hamilton ◽  
Shaik Jeelani
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
High Speed ◽  
High Vacuum ◽  
Test Results ◽  
Trapped Air ◽  
Set Up ◽  
Flexural Tests ◽  
Mechanical Agitator ◽  
Mmt Clay

In the present investigation, a high intensity ultrasonic liquid processor was used to obtain a homogeneous molecular mixture of epoxy resin and K-10 MMT clay. The clay were infused into the part A of SC-15 (Diglycidylether of Bisphenol A) through sonic cavitations and then mixed with part B of SC-15 (cycloaliphatic amine hardener) using a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using high vacuum. Flexural tests were performed on unfilled, 1wt. %, 2wt. %, 3 wt. % and 4 wt.% clay filled SC-15 epoxy to identify the loading effect on mechanical properties of the composites. The flexural test results indicate that 2.0 wt% loading of clay in epoxy resin showed the highest improvement in strength as compared to the neat systems. After that, the nanophased matrix with 2 wt.% clay is then utilized in a Vacuum Assisted Resin Transfer Molding (VARTM) set up with satin weave carbon preforms to fabricate laminated composites. The resulting structural composites have been tested under flexural and tensile loads to evaluate mechanical properties. 13.5% improvement in flexural strength and 5.8% improvement in tensile strength were observed in carbon/epoxy nanocomposite. TGA and DMA tests were also conducted to observe the thermal stability of the structural composite.

scholarly journals A novel technique for the assessment of mechanical properties of vascular tissue

2020 ◽  
Vol 19 (5) ◽  
pp. 1585-1594 ◽  
Author(s):  
Stefan N. Sanders ◽  
Richard G. P. Lopata ◽  
Lambert C. A. van Breemen ◽  
Frans N. van de Vosse ◽  
Marcel C. M. Rutten
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
High Speed ◽  
Vascular Tissue ◽  
Plaque Rupture ◽  
Tensile Tests ◽  
Accurate Estimation ◽  
Uniaxial Tensile ◽  
Inflation Experiment ◽  
Set Up

Abstract Accurate estimation of mechanical properties of the different atherosclerotic plaque constituents is important in assessing plaque rupture risk. The aim of this study was to develop an experimental set-up to assess material properties of vascular tissue, while applying physiological loading and being able to capture heterogeneity. To do so, a ring-inflation experimental set-up was developed in which a transverse slice of an artery was loaded in the radial direction, while the displacement was estimated from images recorded by a high-speed video camera. The performance of the set-up was evaluated using seven rubber samples and validated with uniaxial tensile tests. For four healthy porcine carotid arteries, material properties were estimated using ultrasound strain imaging in whole-vessel-inflation experiments and compared to the properties estimated with the ring-inflation experiment. A 1D axisymmetric finite element model was used to estimate the material parameters from the measured pressures and diameters, using a neo-Hookean and Holzapfel–Gasser–Ogden material model for the rubber and porcine samples, respectively. Reproducible results were obtained with the ring-inflation experiment for both rubber and porcine samples. Similar mean stiffness values were found in the ring-inflation and tensile tests for the rubber samples as 202 kPa and 206 kPa, respectively. Comparable results were obtained in vessel-inflation experiments using ultrasound and the proposed ring-inflation experiment. This inflation set-up is suitable for the assessment of material properties of healthy vascular tissue in vitro. It could also be used as part of a method for the assessment of heterogeneous material properties, such as in atherosclerotic plaques.

Numerical Analysis on High Speed Liquid-Solid Impact of 17-4PH Material

2014 ◽  
Vol 548-549 ◽  
pp. 147-151
Author(s):  
Ming Li ◽  
Peng Fei Zhao ◽  
Guang Hui Wang ◽  
Jing Liu
Keyword(s):  
High Speed ◽  
Nuclear Power ◽  
Vertical Direction ◽  
Maximum Pressure ◽  
Solid Target ◽  
Initial Speed ◽  
Maximum Deformation ◽  
Impact Theory ◽  
Set Up ◽  
Symmetry Mode

In this paper, anaxis-symmetry mode is set up to simulate the high speed liquid-solid impact of 17-4ph material, which is widely used inwet steam turbine bladesof the nuclear power units. The initial speed of the droplet with the diameter of 0.3mm is 400m/s. The deformation of the solid and the stress distribution variation with time are obtained via numerical method. And the variation of the pressure inside the droplet and solid target has also been analyzed in detail. In this case, the maximum pressure in the vertical direction of the solid is 1099MPa, and the maximum deformation distance of the plateis 140nm. The results provide useful supplement and reference to the high-speed liquid-solid impact theory.

Study on Characteristics of Green Parts of Birch Flour/Polyester Composite by Selective Laser Sintering

2015 ◽  
Vol 667 ◽  
pp. 314-319
Author(s):  
De Jin Zhao ◽  
Yan Ling Guo ◽  
Wen Long Song ◽  
Zhang Hui ◽  
Zhi Xiang Yu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
High Speed ◽  
Single Layer ◽  
Laser Sintering ◽  
Empirical Method ◽  
Raw Material ◽  
Polyester Composite ◽  
Scan Speed ◽  
Progressive Scan

In this paper, the birch flour was the raw material with its particle size less than 100μm and the polyester hot-melt adhesive was used as binder with its particle size less than 60μm. The birch flour was dried using high speed mixer with heating function. The birch flour/polyester composite were prepared using the physical mixing method. The surface of the specimen and fracture surface of specimen were analyzed through the micrographs of scanning electron microscopy. In order to study the characteristics of laser sintering, the preheating temperature of the powder bed of laser sintering machine and the processing parameters of the birch flour/polyester composite were determined using single layer sintering method and empirical method. The tensile, flexural and impact specimens were built in the two scanning laser ways of subarea scan and progressive scan. The testing results show that the mechanical properties using subarea scan method are superior to those of progressive scan method and the mechanical properties of the specimens increase as the laser scan speed decreases. The best mechanical properties of SLS specimens of brich flour/polyester composite powder were obtained with the following parameters: the laser power was 11W, layer scan speed was 1800mm/s; layer thickness was 0.1mm; laser scan spacing was 0.1mm and the average tensile, flexural and impact strength of specimens were 1.35MPa, 3.69Mpa and 0.73KJ/m2 respectively.

Influence of ageing treatment on microstructure, mechanical properties and adhesive wear behaviour of 6063 aluminium alloy

2014 ◽  
Vol 66 (4) ◽  
pp. 520-524 ◽  
Author(s):  
Serkan Büyükdoğan ◽  
Süleyman Gündüz ◽  
Mustafa Türkmen
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
High Speed ◽  
Al Alloys ◽  
Wear Behaviour ◽  
Al Alloy ◽  
Strain Ageing ◽  
Content Type ◽  
Static Strain ◽  
Structural Applications

Purpose – The paper aims to provide new observations about static strain ageing in aluminium (Al) alloys which are widely used in structural applications. Design/methodology/approach – The present work aims to provide theoretical and practical information to industries or researchers who may be interested in the effect of static strain ageing on mechanical properties of Al alloys. The data are sorted into the following sections: introduction, materials and experimental procedure, results and discussion and conclusions. Findings – Tensile strength, proof strength (0.2 per cent) and percentage elongation measurement were used to investigate the effect of strain ageing on the mechanical properties. Wear tests were performed by sliding the pin specimens, which were prepared from as-received, solution heat-treated, deformed and undeformed specimens after ageing, on high-speed tool steel (64 HRC). It is concluded that the variations in ageing time improved the strength and wear resistance of the 6063 Al alloy; however, a plastically deformed solution-treated alloy has higher strength and wear resistance than undeformed specimens for different ageing times at 180°C. Practical implications – A very useful source of information for industries using or planning to produce Al alloys. Originality/value – This paper fulfils an identified resource need and offers practical help to the industries.

scholarly journals Fiber Formation and Structural Development of HBA/HNA Thermotropic Liquid Crystalline Polymer in High-Speed Melt Spinning

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1134
Author(s):  
Bo Seok Song ◽  
Jun Young Lee ◽  
Sun Hwa Jang ◽  
Wan-Gyu Hahm
Keyword(s):  
Mechanical Properties ◽  
Shear Rate ◽  
High Speed ◽  
Melt Spinning ◽  
Liquid Crystalline Polymer ◽  
Liquid Crystalline ◽  
Crystalline Polymer ◽  
Fiber Formation ◽  
Structural Development ◽  
Thermotropic Liquid Crystalline Polymer

High-speed melt spinning of thermotropic liquid crystalline polymer (TLCP) resin composed of 4-hydroxybenzoic acid (HBA) and 2-hydroxy-6-napthoic acid (HNA) monomers in a molar ratio of 73/27 was conducted to investigate the characteristic structure development of the fibers under industrial spinning conditions, and the obtained as-spun TLCP fibers were analyzed in detail. The tensile strength and modulus of the fibers increased with shear rate in nozzle hole, draft in spin-line and spinning temperature and exhibited the high values of approximately 1.1 and 63 GPa, respectively, comparable to those of industrial as-spun TLCP fibers, at a shear rate of 70,000 s−1 and a draft of 25. X-ray diffraction demonstrated that the mechanical properties of the fibers increased with the crystalline orientation factor (fc) and the fractions of highly oriented crystalline and non-crystalline anisotropic phases. The results of structure analysis indicated that a characteristic skin–core structure developed at high drafts (i.e., spinning velocity) and low spinning temperatures, which contributed to weakening the mechanical properties of the TLCP fibers. It is supposed that this heterogeneous structure in the cross-section of the fibers was induced by differences in the cooling rates of the skin and core of the fiber in the spin-line.

scholarly journals Mesoscale Modelling of Concretes Subjected to Triaxial Loadings: Mechanical Properties and Fracture Behaviour

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1099
Author(s):  
Qingqing Chen ◽  
Yuhang Zhang ◽  
Tingting Zhao ◽  
Zhiyong Wang ◽  
Zhihua Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
Failure Criterion ◽  
Mesoscale Model ◽  
Fracture Behaviour ◽  
Descent Method ◽  
Triaxial Stress ◽  
Gradient Descent Method ◽  
Stress States ◽  
Shear Failures

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.

scholarly journals Enhanced electrical conductivity and mechanical properties in thermally stable fine-grained copper wire

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Qingzhong Mao ◽  
Yusheng Zhang ◽  
Yazhou Guo ◽  
Yonghao Zhao
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Electrical Conductivity ◽  
Yield Strength ◽  
High Speed ◽  
Copper Wire ◽  
Rapid Development ◽  
Dislocation Slip ◽  
Ultrafine Grains ◽  
The Wire

AbstractThe rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.

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