Wyniki wyszukiwania - Biblioteka Nauki

1

Climbing Robot Modelling Based on Grab Claws

100%

Xu F. , Jiang G.

Przegląd Elektrotechniczny

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2013

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tom R. 89, nr 3b

182--187

EN

Though the wall-climbing robots have be used extensively, however, no effective adhesion system has been designed for robots deployed in high-altitude, rough concrete buildings that are subjected to large wind loads and vibrations. Therefore, an initial design of a wall-climbing robot based on grab claw is presented and a climbing model is proposed in the paper. The mathematical model is established to reflect the relations between sharp hook and the micro-protuberance on the rough wall surface The stress on the hook-like claws is analyzed under three different conditions, so the steady grasping condition of the hook-like claws is obtained. Simulation results are carried out which demonstrates the stability of the grasping. Finally, the system outline and field implement scheme are presented.

PL

W artykule przedstawiono projekt wspinającego się robota, opartego na chwytaku w postaci pazura. Zaproponowano także matematyczny model wspinania, pozwalający określić wpływ mikro-fałd na powierzchni pionowej na możliwość chwytania hakiem. Przeanalizowano możliwości obciążenia haka w trzech różnych warunkach pracy. Przeprowadzono badania symulacyjne i eksperymentalne w celu weryfikacji modelu.

2

Rapid Simulation of Flat Knitting Loops Based On the Yarn Texture and Loop Geometrical Model

100%

Lu Z. , Jiang G.

Autex Research Journal

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2017

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tom Vol. 17, no. 2

103--110

EN

In order to create realistic loop primitives suitable for the fast computer-aided design (CAD) of the flat knitted fabric, we have a research on the geometric model of the loop as well as the variation of the loop surface. Establish the texture variation model based on the changing process from the normal yarn to loop that provides the realistic texture of the simulative loop. Then optimize the simulative loop based on illumination variation. This paper develops the computer program with the optimization algorithm and achieves the loop simulation of different yarns to verify the feasibility of the proposed algorithm. Our work provides a fast CAD of the flat knitted fabric with loop simulation, and it is not only more realistic but also material adjustable. Meanwhile it also provides theoretical value for the flat knitted fabric computer simulation.

3

Emission characteristics for waste cooking oil biodiesel blend in a marine diesel propulsion engine

80%

Wu G. , Jiang G. , Yang Z. , Huang Z.

Polish Journal of Environmental Studies

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2019

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tom 28

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nr 4

EN

Diesel engines are widely used for propulsion on large ships, which has the undesired characteristic of generating large amounts of harmful emissions. To reduce these emissions, some alternative fuel was developed and used in a marine diesel engine. In this study, an experiment was carried out on a 6-cylinder turbocharged direct-injection marine diesel propulsion engine. A small proportion blend of biodiesel-diesel was used, aimed at exploring the emission characteristics and emission reduction mechanism for diesel propulsion engines. The results show that the high oxygen content of biodiesel blend is crucial for inhibiting the formation of particulate matter (PM) and reducing the formation of total unburned hydrocarbon (THC) and carbon monoxide (CO), which reduces the emission of harmful gases. At the same time, the number of particles (PN) has also decreased. However, the rapid burn rate of biodiesel was found to reduce brake thermal efficiency (BTE), resulting in an increase of fuel consumption and exhaust gas temperature (EGT), which can promote the formation of nitrogen oxides (NOx). More carbon dioxide (CO2) is released due to the increased fuel consumption. The emission characteristics of the biodiesel blend and diesel fuel are discussed in this work.

4

Effects of human activities on the spatial distribution of eastern roe deer Capreolus pygargus bedfordi in the Lesser Khingan Mountains, northeastern China

80%

Jiang G. , Ma J. , Zhang M. , Stott P.

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nr 1

61-76

EN

Eastern roe deerCapreolus pygargus bedfordi Thomas, 1908 occurred throughout China historically, but today are only found in 7 provinces. Their populations in China have been greatly impacted by human disturbances. Little is known about what kinds of human disturbances impact their distribution and resource requirements for survival. A survey was conducted over 20 661 ha located at the Erkehe Forestry Farm in the Lesser Khingan Mountains, northeastern China. Field work lasted from January to March, 2006 and January to March, 2007, and a total of 613 plots were visited along 28 sampling transects. Predictive models of easter roe deer resource selection were developed with or without the inclusion of human disturbance factors. Whether human disturbance exists or not, eastern roe deer retained strong links to patch size and patch density of low shrub and swamp, and the probability of moose occurrence. Low shrub and swamps created after logging provide more abundant annual shoots for food, and were vital for survival in harsh winters. When human disturbance was not modeled, eastern roe deer avoided higher density of bothBetula platyphylla andLarix gmelinii patches at a landscape scale, and larger mixed coniferous and broad-leaf patchs at local scales. Once human disturbances existed, eastern roe deer occurred in areas with higher NDVI and they had a considerably lower probability of presence in areas associated with roads and with a forest harvest interval of 4 years. Consequently, to predict effects of human disturbance on eastern roe deer spatial distribution, models need to incorporate effects of other competitive species, multiple spatial scale resource variables respectively, which will provide more value information for management and use of eastern roe deer population.

5

Three-Dimensional Simulation of Warp-knitted Fabric

80%

Cong H. , Ge M. , Jiang G.

Fibres & Textiles in Eastern Europe

|

2009

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tom Vol. 17, no. 3 (74)

66--69

EN

With detailed research on the structure of warp-knitted fabric, the spatial yarn position of a 3D loop structure was discussed, and the dimension of each parameter was ascertained. After establishing the basic control points of the loop, a 3D model of warp-knitted fabric was created. By calculating the control points of this model in reverse, a more exact control polygon was attained. By utilizing the program Visual C++ and the developing tools of Open GL, using Non-Uniform Rational B-Spline surfaces, spatial yarn can be described exactly, and a virtual reality of warp-knitted fabric can be realized on a computer screen.

PL

Szczegółowo przeanalizowano strukturę dzianiny osnowowej, przestrzenne usytuowanie przędzy w oczku 3D oraz określono wartości wszystkich istotnych parametrów. Po określeniu wszystkich podstawowych punktów konturu oczka sporządzono model 3D dzianiny osnowowej. W wyniku przeliczania pozycji punktów kontrolnych modelu sporządzono precyzyjny kontrolny wielobok. Dzięki wykorzystaniu programu Visual C++ oraz narzędzi Open GL i Non-Uniform Rational B-Spline Surfaces przestrzenne położenie przędzy może być opisane a także można stworzyć wirtualny obraz dzianiny osnowowej za pomocą komputera.

6

Warp-Knitted Fabric Defect Segmentation Based on Non-Subsampled Wavelet-Based Contourlet Transform

80%

Xia D. , Jiang G. , Ma P.

Autex Research Journal

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2017

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tom Vol. 17, no. 4

319--327

EN

In this paper, a non-subsampled wavelet-based contourlet transform (NWCT) is applied in warp-knitted fabric defect segmentation. Compared with the traditional contourlet transform, wavelet transform takes the place of Laplacian pyramid in NWCT and the directional filter bank is non-subsampled. The wavelet transform with improved wavelet threshold is put to use, and the original fabric image can be decomposed into low-frequency approximate coefficient A and high-frequency detail coefficients V, H, and D. The high-frequency detail coefficients are processed by the non-subsampled directional filter bank to get directional sub-band coefficients. Afterward, the effective sub-band coefficients based on regional energy are chosen to reconstruct V, H, and D. And the reconstructed fabric image will be achieved by inverse non-subsampled wavelet-based contourlet transform. The adaptive threshold method and morphological processing are used to obtain the legible defect profile. The experiment demonstrates that NWCT can achieve the positive segmentation regarding the common defects, such as broken warp, width barrier, and oil, and has excellent performance on these directional defects and regional defects. It is acknowledged that NWCT will provide a new way to detect warp-knitted fabric defects automatically.

7

Design of Rascheltronic Vamp Fabric with Double-Colour Pitting Effect

80%

Li X. , Zhang A. , Jiang G.

Fibres & Textiles in Eastern Europe

|

2017

|

tom Vol. 25, no. 3 (123)

92--97

EN

Applications of Piezo jacquard and CAD technology in warp-knitting have provided traditional jacquard fabrics with the possibility of innovating the structure design. Research on innovative design and fabrication is conducted aiming at knitting jacquard vamp fabric with the double-colour pitting effect on a technical back. By utilising Piezoelectric jacquard’s performance of displacing both underlapping and overlapping, new structures are formed, such as mesh stitches, koper stitches and float structures. Based on threading with yarns in two colors, jacquard bars in split execution create a pattern with a double-colour effect. To realize a highly efficient design, the paper proposes a computer-aided jacquard design method covering technical parameters and jacquard pattern design modules. Additionally, to pursue convenience and efficiency, mathematic models are built in terms of an automatic borderline design, loop stitching inspection and structure database. The method of jacquard vamp fabric design with a double-color pitting effect has been proven practically by illustrating a vamp design example which meets the requirement of fashion and performance well.

PL

Projektowanie dzianin dwukolorowych z efektem pittingu jest możliwe przy użyciu komputerowego systemu projektowania opartego na specjalnej metodzie dziewiarskiej. Dzięki macierzy i modelowi matematycznemu system obejmuje wszystkie podstawowe parametry techniczne modułów projektowego i kontrolnego oraz modułu bazy danych struktur, które współpracują w celu sprawnego projektowania dzianiny. Na podstawie otrzymanych wyników badań stwierdzono, że wspomagana komputerowo metoda projektowania może być z powodzeniem stosowana w projektowaniu dzianin dwukolorowych z efektem pittingu.

8

The Development of the Flat-Knitted Shaped Uppers based on Ergonomics

80%

Lu Z. , Jiang G. , Cong H. , Yang X.

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tom Vol. 16, no. 2

67--74

EN

To achieve the efficiency and specification of the flat-knitted uppers design, the basic patterns of uppers are made from shoe lasts based on the research on the characteristics of human’s feet and wearability requirements on uppers. The knitting technology for half-shaped and fully shaped uppers was formed after the shear deformation of basic pattern and combination with flat knitting technology. As regards to the functional requirements on key parts of uppers, the structures of flat-knitted shaped uppers were intensively analysed and studied, dividing them into two categories (functional structure and decorative structure), discussing the knitting methods and advantages of different structure, and finally experimentally proving that the planar pattern of flat knitted uppers can apply to the design of flat-knitted uppers and achieve the combination of functionality and artistry of sneakers after combining with structural changes, with a great significance on the achievement of the efficient production of uppers and the enhancement of its commercial value.

9

Design and experiment of low-pressure gas supply system for dual fuel engine

80%

Gu X. , Jiang G. , Guo Z. , Ding S.

|

nr 2

10

Effects of human disturbance on movement, foraging and bed selection in red deer Cervus elaphus xanthopygus from the Wandashan Mountains, northeastern China

80%

Jiang G. , Zhang M. , Ma J.

Acta Theriologica

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2007

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tom 52

|

nr 4

435-446

EN

We characterized 716 sites (including 22 beds, 60 foraging and 604 movement sites) used by red deerCervus elaphus xanthopygus Milne-Edwards, 1867 in the Wandashan Mountains, northeastern China in the winter period. We used covariates for vegetation, topography, disturbances by other ungulates, and disturbance by humans to develop movement, forage and bed site resource-selection models. We used an information-theoretic approach to select the top 5 models for movement, forage and bed site occurrences respectively. The three most parsimonious autologistic models were good predictors of movement, forage and bed occurrence of this species. Vegetation covariates were important components of all models. We recorded avoidance responses by the behaviours of species to each disturbance type (ie, villages, forest roads and abandoned roads); bed site occurrences were most sensitive to all human disturbances for their lowest odds encountered. Across all parsimonious models, villages have the largest negative effect on movement, foraging and bed occurrences. Movement and bedding behaviours were also affected by other ungulate disturbances. Altitude had slightly negative effect on movement and foraging behaviours. Ridges, topographic aspect and shrub stands were all correlated with bed-site selection. Although different behaviours may be associated with different microhabitat features, behaviours of red deer responded similarly to the same human disturbance on a broad scale. Based on the observations above, we believe that red deer are avoiding human-altered habitat for movement, bedding and foraging because of disturbances during the critical late winter period. Furthermore, various behavioural resource selection models and corresponding graphs of important habitat disturbances can be used to guide and evaluate future development proposals.

11

Reliability allocation using probabilistic analytical target cascading with efficient uncertainty propagation

80%

Jiang G. , Zhu M. , Wu Z.

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tom Vol. 14, No. 4

270-277

EN

Analytical target cascading (ATC) provides a systematic approach in solving reliability allocation problems for large scale system consisting of a large number of subsystems, modules and components. However, variability and uncertainty in design variables (e.g., component reliability) are usually inevitable, and when they are taken into consideration, the multi-level optimization will be very complicated. The impacts of uncertainty on system reliability are considered in this paper within the context of probabilistic ATC (PATC) formulation. The challenge is to reformulate constraints probabilistically and estimate uncertainty propagation throughout the hierarchy since outputs of subsystems at lower levels constitute inputs of subsystems at higher levels. The performance measure approach (PMA) and the performance moment integration (PMI) method are used to deal with the two objectives respectively. To accelerate the probabilistic optimization in each subsystem, a unified framework for integrating reliability analysis and moment estimation is proposed by incorporating PATC with single-loop method. It converts the probabilistic optimization problem into an equivalent deterministic optimization problem. The computational efficiency is remarkably improved as the lack of iterative process during uncertainty analysis. A nonlinear geometric programming example and a reliability allocation example are used to demonstrate the efficiency and accuracy of the proposed method.

PL

Analityczne kaskadowanie celów (ATC) stanowi systematyczne podejście do rozwiązywania zagadnień alokacji niezawodności dotyczących systemów wielkoskalowych składających się z dużej liczby podsystemów, modułów i elementów składowych. Jednakże zmienność i niepewność zmiennych projektowych (np. niezawodności elementów składowych) są zazwyczaj nieuniknione, a gdy weźmie się je pod uwagę, optymalizacja wielopoziomowa staje się bardzo skomplikowana. W prezentowanym artykule, wpływ niepewności na niezawodność systemu rozważano w kontekście formuły probabilistycznego ATC (PATC). Wyzwanie polegało na probabilistycznym przeformułowaniu ograniczeń oraz ocenie propagacji niepewności w całej hierarchii, jako że wyjścia podsystemów na niższych poziomach stanowią wejścia podsystemów na poziomach wyższych. Cele te realizowano, odpowiednio, przy użyciu metody minimum funkcji granicznej (performance measure approach, PMA) oraz metody całkowania momentów statystycznych funkcji granicznej (performance moment integration, PMI). W celu przyspieszenia probabilistycznej optymalizacji w każdym podsystemie, zaproponowano ujednolicone ramy pozwalające na integrację analizy niezawodności z oceną momentów statystycznych poprzez połączenie PATC z metodą jednopoziomową (pojedynczej pętli, single-loop method). Zaproponowana metoda polega na przekształceniu probabilistycznego zagadnienia optymalizacyjnego na deterministyczne zagadnienie optymalizacyjne. Zwiększa to znacznie wydajność obliczeniową w związku z brakiem procesu iteratywnego podczas analizy niepewności. Wydajność i trafność proponowanej metody wykazano na podstawie przykładów dotyczących programowania nieliniowego geometrycznego oraz alokacji niezawodności.

12

Warp-knitted Fabric Defect Segmentation Based on the Shearlet Transform

80%

Dong Z. , Xia D. , Ma P. , Jiang G.

Fibres & Textiles in Eastern Europe

|

2017

|

tom Vol. 25, no. 5 (125)

87--94

EN

The Shearlet transform has been a burgeoning method applied in the area of image processing recently which, differing from the Wavelet transform, has excellent properties in processing singularities for multidimensional signals. Not only is it similar to the performance of the Curvelet transform, it also overcomes the disadvantage of the Curvelet transform with respect to discretization. In this paper, the Shearlet transform with segmented threshold de-nosing is proposed to segment a warp-knitted fabric defect. Firstly a warp-knitted fabric image of size 512*512 is filtered by the Laplacian Pyramid transform and decomposed into low frequency and high frequency coefficients. Secondly the high frequency coefficients are operated with a pseudo-polar grid and then convoluted by the window function. Thirdly the shearlet coefficients will be obtained through redefining the Cartesian coordinates from the pseudo-polar grid coordinates and de-noised by the segmented threshold method. Then the coefficients which have high energy are selected for reconstruction in an inverse way using the previous steps. Finally the iterative threshold method and object operation based on morphology are applied to segment out the defect profile. The experiment’s result states that the Shearlet transform shows excellent performance in segmenting a common warp-knitted fabric defect, indicating that the segment results can be applied for further defect automatic recognition.

PL

Transformacja Shearleta jest ostatnio dynamicznie rozwijającą się metodą stosowaną w dziedzinie przetwarzania obrazu, która różni się od transformaty Wavelet i ma doskonałe właściwości w przetwarzaniu sygnałów wielowymiarowych. Transformacja Shearleta ma prostszą implementację dyskretną, niż przekształcenie Curveleta w oparciu o rygorystyczne i proste ramy matematyczne. Może także dostarczyć bardziej elastycznego rozkładu na podstawie reprezentacji wieloskalowej i geometrycznej. Ostateczny wynik segmentacji uzyskano poprzez powtarzalną segmentację progową i operację morfologiczną. Wyniki wykazały, że segmentowy profil uszkodzeń jest dość wyraźny i porównywalny w porównaniu z pierwotnymi wadami dzianiny.

13

Computer-Aided Design Method of Warp-Knitted Jacquard Spacer Fabrics

80%

Li X. , Jiang G. , Ma P.

|

tom Vol. 16, no. 2

51--56

EN

Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.

14

Experimental Investigation on the Stab Resistance of Warp Knitted Fabrics

80%

Miao X. , Jiang G. , Kong X. , Zhao S.

|

tom Vol. 22, no. 5 (107)

65--70

EN

The stab resistance of two guide bar warp knitted fabric made from ultra-high molecular weight polyethylene was characterised by a maximum load, and energy at the maximum load and load versus displacement curves under quasi-static test conditions are presented. Penetration angles and side were designed. Samples with different lapping, densities and layers were tested, with a woven fabric used as the original reference. The results showed that warp knitted fabric with a moderate density and longer underlaps on the front guide bar performed better. The penetration angle and side have no observable influence on warp knitted fabrics’ stab resistance. Furthermore the performance of warp knitted fabrics during a knife penetration shows the difference from woven fabric in the damage process.

PL

W artykule stwierdzono, że odporność na przebicie specjalnych dzianin osnowowych wykonanych z włókien polietylenowych o ultra wysokim ciężarze cząsteczkowym można charakteryzować poprzez maksymalne obciążenie przy przebiciu, energię w chwili maksymalnego obciążenia i krzywymi obciążenia w funkcji przemieszczenia w warunkach testowych quasi statycznych. Między innymi określono kąty penetracji . Przygotowano próbki o różnej strukturze, masie liniowej i ilości warstw. Wyniki porównywano w stosunku do wyników uzyskanych dla tkaniny. Wyniki wskazują, że dzianiny osnowowe o średniej masie liniowej i dłuższych łącznikach oczek są bardziej odporne na przebicie. Natomiast nie stwierdzono wyraźnego wpływu kąta przebicia. Ogólnie stwierdzono wyraźną różnicę zachowania się dzianin w stosunku do tkanin przy penetracji nożem.

15

3-D Simulation of Double-Bar Plush Fabrics with Jacquard Patterns

71%

Zhang A. , Li X. , Jiang G. , Dong Z. , Cong H.

Autex Research Journal

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2018

|

tom Vol. 18, no. 3

243--250

EN

A realistic computerized simulation of double-bar plush fabrics can result in a time-saving development process with high quality. Based on basic analysis of jacquard principles, a fast 3-D simulation method of warp-knitted plush fabrics is proposed by using a geometry shader on GPU. Firstly, pile areas and non-pile areas are identified according to the jacquard design graphs and chain notations. According to the directions of observation and raised pile, two layered chips are formed in the geometry shader with an approach of multi-layered textures. To ensure that the simulated piles resemble the real ones, the directions of the piles are randomized with the Perlin noise method. One pile is generated along its length with numerous layers in the plush fabric model. Simulation results of piles on both the technical face and technical back are obtained via the model built above, which is confirmed with practicability and efficiency. This 3D simulation approach improves the visualization appearance of piles just as they are actually raised.

16

The Effect of Knitting Parameter and Finishing on Elastic Property of PET/PBT Warp Knitted Fabric

71%

Chen Q. , Ma P. , Mao H. , Miao X. , Jiang G.

Autex Research Journal

|

2017

|

tom Vol. 17, no. 4

250--260

EN

This study investigated the elastic elongation and elastic recovery of the elastic warp knittedfabric made of PET (polyethylene terephthalate) and PBT (polybutylene terephthalate) filament. Using 50/24F PET and 50D/24F PBT in two threadingbars, the tricot, locknit and satin warp knitted fabrics were produced on the E28 tricot warpknitting machine. The knitting parameters influencing the elastic elongation under 100N wereanalyzed in terms of fabric structure, yarn run-in speed and drawing density set on machine.Besides, dyeing temperature and heat setting temperature/time were also examined in order toretain proper elastic elongation and elastic recovery. The relationship between elastic elongationand knitting parameter and finishing parameter were analyzed. Finally, the elastic recovery of PET/PBT warp knitted fabric was examined to demonstrate the elastic property of final finishedfabric. This study could help us to further exploit the use of PET/PBT warp knitted fabric in thedevelopment of elastic garment in future.

17

Knitting Technologies And Tensile Properties Of A Novel Curved Flat-Knitted Three-Dimensional Spacer Fabrics

71%

Li X. , Jiang G. , Nie X. , Ma P. , Gao Z.

Autex Research Journal

|

2015

|

tom Vol. 15, no. 3

191--197

EN

This paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.

18

The Comfort Properties of Two Differential-Shrinkage Polyester Warp Knitted Fabrics

71%

Chen Q. , Miao X. , Mao H. , Ma P. , Jiang G.

|

tom Vol. 16, no. 2

90--99

EN

Single-layered warp knitted fabrics were produced by the 60D/36F (containing 36 filaments) polyester yarn with differential shrinkage (DS) property in this study. Due to the differential shrinkage property, the fabric becomes curly and bulkier, simulating cotton fabric in terms of its appearance and fabric handle. The performance and appearance of these DS polyester warp knitted fabrics were evaluated objectively and subjectively. The testing results demonstrated that the DS polyester warp knitted fabric had better abrasion property, worse pilling resistance due to the mechanical property of polyester yarn when compared with 100% cotton warp knitted fabric. Meanwhile, lower water vapour permeability and air resistance were found for DS polyester warp knitted fabric resulting from the dense structure of yarn shrinkage after heat-moisture treatment. Besides, the fabric handle was evaluated by Kawabata evaluation system and subject to trial under dry and wet fabric condition. DS polyester warp knitted fabrics provide better recovery under low stress mechanical pressure. The subjective evaluation result shows that the warp knitted fabrics made of DS polyester had similar handle against cotton warp knitted fabric in terms of prickle, smooth, comfort and dry feeling in both dry and wet testing conditions.

19

Disparity servoing based fast autofocusing method for stereomicroscope

61%

Liu Y. , Yu M. , Cui L. , Jiang G. , Wang G. , Fan S.

Optica Applicata

|

2016

|

tom Vol. 46, nr 4

651--663

EN

A disparity servoing based fast autofocusing method is proposed for stereomicroscopes according to linear relationship between the disparity change in stereomicroscopic images and the move distance of a motorized translation stage. For a certain stereomicroscope, the calibration of a disparity range of clear images at each magnification is implemented offline. After that, the disparity of the stereomicroscopic image is used as an index to represent the sharpness of an arbitrary image. If the disparity does not satisfy the requirement, move steps and direction of a step motor are calculated by utilizing the linear relationship between the disparity change and the move distance of the stage. The iteration will be continued until the disparity of the captured stereomicroscopic image approximates to the clearest disparity. The experimental results show that the proposed method only requires a few iterations and less time to reach the focus position, and the disparity error is less than 0.5 pixel.

20

Experimental Investigation on the Compression Behaviours of 3D Angle‑interlock Woven Composites with Carbons Nanotube under High Strain Rates

61%

Ma P. , Jiang G. , Zhang F. , Chen Q. , Miao X. , Cong H.

Fibres & Textiles in Eastern Europe

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2015

|

tom Vol. 23, no. 2 (110)

44--50

EN

The compressive properties of 3D angle-interlock woven/epoxy resin composites with various carbon nanotube (CNTs) contents were investigated under quasi-static and high strain rate loading to evaluate the compressive failure modes, which were influenced by various CNT contents and different strain rates. The results indicated that the stress strain curves were strain rate sensitive, and the compressive failure stress of composites with various CNT contents were increased with a change the strain rates and CNT contents. The compressive failure modes of 3D angle-interlock woven composites without CNT tended to be in shear deformation, delamination fibre breakage and matrix crack together, and the failure modes of 3D angle-interlock woven composites with high CNT contents presented delamination and shear deformation.

PL

Badano właściwości ściskające kompozytów 3D wzmacnianych tkaninami o skośnym splocie interlokowym modyfikowanych nanorurkami węglowymi. W celu wyznaczenia uszkodzeń powstałych na skutek ściskania, na które wpływa zawartość nanorurek i szybkości odkształcania, badania przeprowadzono pod obciążeniem quasi-statycznym i przy dużych szybkościach ściskania. Wyniki wykazały, że krzywe ściskania zależały od szybkości odkształcania i zawartości nanorurek. Uszkodzenia mają charakter rozwarstwienia i deformacji pod wpływem naprężeń ścinających.