scholarly journals Static and cyclic performance of cementitious composites reinforced with glass-fibres

2018 ◽  
Vol 68 (329) ◽  
pp. 146 ◽  
Author(s):  
N. Arabi
Keyword(s):  
Matrix Material ◽  
Fibre Length ◽  
Fatigue Behaviour ◽  
Application Rate ◽  
Compression Tests ◽  
Glass Fibres ◽  
The Matrix ◽  
Reinforced Cement ◽  
Matrix Reinforcement ◽  
Number Of Cycles

This paper concerns an experimental study of the influence of short glass-fibres randomly oriented of a reinforced cement-based composite on the mechanical behaviour. The matrix material parameters used are: cement/sand ratio and water/cement ratio fixed at 0.5; the glass-fibre content (0%, 0.5%, 1.0%, 1.5%, 2% and 2.5%) and fibre lengths (3, 6 and 12 mm). Composites mechanical characterisation under static behaviour at flexural and compression tests, shows that the reinforcement effect is beneficial only in flexural case. A synergy (matrix-reinforcement) was observed when fibre length of 12 mm is used with application rate of 2% in flexural. The fatigue behaviour determined by Wöhler plots (stress-number of cycles to rupture), derived from experimental results; showed a large results dispersion which is attributed to many causes initiating this damage. The cyclic tests illustrate brittle character of these materials; even with low-amplitude cycles of loading no adaptation of these materials can be reported.

scholarly journals Effects of Knit Stretching and Matrix Crystallinity on the Fatigue Behaviour of Knitted Fabric-Reinforced Gf/Pet Composites

1997 ◽  
Vol 6 (3) ◽  
pp. 096369359700600 ◽  
Author(s):  
E. Moos ◽  
J. Karger-Kocsis
Keyword(s):  
Endurance Limit ◽  
Damage Zone ◽  
Stress Transfer ◽  
Fatigue Behaviour ◽  
Knitted Fabric ◽  
The Matrix ◽  
Static Tensile ◽  
Matrix Morphology ◽  
Number Of Cycles ◽  
Fatigue Endurance

In this study the tension-tension fatigue behaviour of weft-knitted glass fibre fabric-reinforced polyethylene terephthalate (GF/PET) composites was studied as a function of the stretching ratio of the knit The knits were stretched prior to consolidation in wale direction in 0, 25, 50 and 73%, respectively, in order to increase the anisotropy and to alter the mechanical properties of the composites. The influence of the matrix morphology (crystalline, amorphous) on the fatigue response was also investigated by using a composite with unstretched knit reinforcement. The results, displayed in normalized maximum fatigue stress Ms number of cycles (S-N) diagrams showed that the fatigue endurance limit of the GF/PET composites did not depend either on the knit stretching or the matrix crystallinity. The fatigue endurance limit, normalized to the static tensile strength, was found at ≍27 and ≍50 % for the knitted fabric-reinforced composite sheets tested in wale (W) and course (C) direction, respectively. The damage zone seemed to be localized for 1 and 2 rows of loops in C-and W-directions, respectively. This failure mode reflects the stress transfer and redistribution capability of the plain weft-knit reinforcement

scholarly journals Effect of Reactive SPS on the Microstructure and Properties of a Dual-Phase Ni-Al Intermetallic Compound and Ni-Al-TiB2 Composite

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5668
Author(s):  
Paweł Hyjek ◽  
Iwona Sulima ◽  
Piotr Malczewski ◽  
Krzysztof Bryła ◽  
Lucyna Jaworska
Keyword(s):  
Intermetallic Compound ◽  
Tribological Properties ◽  
Matrix Material ◽  
Dual Phase ◽  
Compression Tests ◽  
Two Phase ◽  
Alloy Matrix ◽  
Plastic Properties ◽  
Mechanical And Tribological Properties ◽  
The Matrix

As part of the tests, a two-phase NiAl/Ni3Al alloy and a composite based on this alloy with 4 vol% addition of TiB2 were produced by the reactive FAST/SPS (Field Assisted Sintering Technology/Spark Plasma Sintering) sintering method. The sintering process was carried out at 1273 K for 30 s under an argon atmosphere. The effect of reactive SPS on the density, microstructure, and mechanical and tribological properties of a dual-phase Ni-Al intermetallic compound and Ni-Al-TiB2 composite was investigated. Products obtained were characterized by a high degree of sintering (over 99% of the theoretical density). The microstructure of sinters was characterized by a large diversity, mainly in regard to the structure of the dual-phase alloy (matrix). Compression tests showed satisfactory plastic properties of the manufactured materials, especially at high temperature (1073 K). For both materials at room temperature, the compressive strength was over 3 GPa. The stress–strain curves were observed to assume a different course for the matrix material and composite material, including differences in the maximum plastic flow stress depending on the test temperature. The brittle-to-ductile transition temperature was determined to be above 873 K. The research has revealed differences in the physical, mechanical and tribological properties of the produced sinters. However, the differences favourable for the composite were mostly the result of the addition of TiB2 ceramic particles uniformly distributed on grain boundaries.

scholarly journals Impact of the reinforced metal structure on the mechanical properties foamed aluminium composites at the load

2021 ◽  
Vol 8 (1) ◽  
pp. 318-326
Author(s):  
Olga Mareeva ◽  
Vladimir Ermilov ◽  
Vera Snezhko ◽  
Dmitrii Benin ◽  
Alexander Bakshtanin
Keyword(s):  
Mechanical Properties ◽  
Deformation Behavior ◽  
Matrix Material ◽  
Metal Structure ◽  
Absorption Capacity ◽  
Large Contribution ◽  
Strain Rates ◽  
Compression Tests ◽  
Stress Plateau ◽  
The Matrix

Abstract This paper is an experimental study of the quasi-static mechanical compressive properties of the reinforced closed-cell aluminum alloy foams with different cell orientations at different strain rates. The reinforced foam samples were obtained via the powder metallurgical route. The results of the compression tests revealed that the deformation behavior and mechanical properties of foamed aluminum composites are highly dependent on the orientation of the reinforcing mesh. Differences in the deformation behavior of foams appear to be influenced by the mechanical properties of the matrix material, by foam deformation mechanisms, and by the mechanical properties of the reinforcement. The yield stress, plateau stress, densification stress, and energy absorption capacity of unreinforced foam samples improved linearly with increasing strain rate due to dynamic recrystallization and softening of the foam matrix material. The reinforced foam samples exhibit nonlinear deformation behavior. It was also found that the mechanical properties reduction of transverse reinforced foams was slightly lower compared to foams with longitudinal reinforcement at varying strain rates because of the large contribution of the mechanical properties of the reinforcement. The results of the present study can be employed to modelling and obtain impact-resistant fillers for complex structures in transport construction.

Fatigue Notch Sensibility of Thermoplastic Glass Fibre Composites

2006 ◽  
Vol 514-516 ◽  
pp. 653-656 ◽  
Author(s):  
Paulo N.B. Reis ◽  
José A. Martins Ferreira ◽  
Fernando Antunes ◽  
José Domingos M. Costa
Keyword(s):  
Experimental Tests ◽  
Fatigue Behaviour ◽  
Thermoplastic Composite ◽  
Flexural Properties ◽  
Glass Fibres ◽  
Notched Specimens ◽  
Fibre Composites ◽  
Number Of Cycles ◽  
Stiffness Loss ◽  
Cycles To Failure

This paper is concerned with a notch sensibility study of a thermoplastic composite produced from a bi-directional woven E-glass fibres and polypropylene. Experimental tests were performed in three points bending using notched and unotched specimens of polypropylene glass fibres reinforced laminates to evaluate flexural properties and fatigue behaviour. Fatigue results were plotted as the stress range against the number of cycles to failure. The fatigue damage was measured in terms of the stiffness loss. The testes carried out using notched specimens present lower values of both static and fatigue strengths than the unnotched specimens tests.

Experimental Investigation during Finishing of Al/SiC-MMC's by Abrasive Flow Machining (AFM) Process

2011 ◽  
Vol 264-265 ◽  
pp. 1130-1136 ◽  
Author(s):  
Harlal Singh Mali ◽  
Alakesh Manna
Keyword(s):  
Surface Finish ◽  
Matrix Material ◽  
Mesh Size ◽  
Stir Casting ◽  
Abrasive Flow Machining ◽  
Size Number ◽  
Sem Study ◽  
The Matrix ◽  
Set Up ◽  
Number Of Cycles

Al/SiCp-MMC’s find their use in engineering and structural components but their machining particularly finishing is a challenge for manufacturing engineers due to their heterogonous nature having abrasive particles randomly distributed and oriented in the matrix material. An abrasive flow machining (AFM) set up has been designed and fabricated with an indigenously developed alternative media to finish the internal cylindrical surfaces of Al/SiCp- MMC components. Work-pieces were prepared by lathe operations after stir casting Al/SiC-MMC, 25 mm diameter bar of 0%, 5%, 10% and 15% SiC by weight. The influence of AFM process parameters e.g. abrasive mesh size, number of cycles, extrusion pressure, abrasive concentration and AFM media viscosity grade on average surface finish improvement, Ra and material removal, MR, mg have been analyzed. The Scanning Electron Microscopy (SEM) study also reveals the improvement in surface finish of these MMC’s.

scholarly journals Effect of Processing and Loading Conditions upon the Fatigue Behaviour of a Cf/Epoxy Laminate

2009 ◽  
Vol 18 (3) ◽  
pp. 096369350901800 ◽  
Author(s):  
Christos Koimtzoglou ◽  
Konstantinos G. Dassios ◽  
Costas Galiotis
Keyword(s):  
Fatigue Limit ◽  
Failure Modes ◽  
Matrix Material ◽  
High Stress ◽  
Fatigue Behaviour ◽  
Static Strength ◽  
Testing Conditions ◽  
The Matrix ◽  
The Mean ◽  
Loading Scheme

The current work reports on the tensile and fatigue behaviour of an autoclave-cured unidirectional carbon fibre reinforced epoxy-matrix laminate. The macromechanical properties of the composite are established under interrupted and uninterrupted, static and dynamic conditions at a maximum strain below the critical fatigue limit of the matrix material. The established S-N curve was used to calculate the endurance fatigue limit of the laminate as well as to record an increase in fatigue life of specimens tested at load levels lower than two standard deviations below the mean static strength of the material. The failure modes exhibited by the composite under all testing conditions were recorded and interpreted by means of the damage mechanisms that originate them. The results of interrupted testing showed that the combined effect of fatigue and residence at high stress levels for prolonged periods of time - conditions that simulate a realistic loading scheme- trigger premature fibre failure and thus specimen failure.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Application of cross correlation to HREM images of surfaces

1987 ◽  
Vol 45 ◽  
pp. 754-755
Author(s):  
D. E. Luzzi ◽  
L. D. Marks ◽  
M. I. Buckett
Keyword(s):  
Cross Correlation ◽  
A Priori ◽  
Matrix Material ◽  
Correlation Method ◽  
Accurate Knowledge ◽  
Complex Image ◽  
Fourier Filtering ◽  
The Matrix ◽  
Low Pass ◽  
Data Reduction Technique

As the HREM becomes increasingly used for the study of dynamic localized phenomena, the development of techniques to recover the desired information from a real image is important. Often, the important features are not strongly scattering in comparison to the matrix material in addition to being masked by statistical and amorphous noise. The desired information will usually involve the accurate knowledge of the position and intensity of the contrast. In order to decipher the desired information from a complex image, cross-correlation (xcf) techniques can be utilized. Unlike other image processing methods which rely on data massaging (e.g. high/low pass filtering or Fourier filtering), the cross-correlation method is a rigorous data reduction technique with no a priori assumptions.We have examined basic cross-correlation procedures using images of discrete gaussian peaks and have developed an iterative procedure to greatly enhance the capabilities of these techniques when the contrast from the peaks overlap.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

2020 ◽  
Vol 38 (7A) ◽  
pp. 960-966
Author(s):  
Aseel M. Abdullah ◽  
Hussein Jaber ◽  
Hanaa A. Al-Kaisy
Keyword(s):  
Impact Strength ◽  
Wear Rate ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Weight Fraction ◽  
Pure Pmma ◽  
Calcination Process ◽  
The Matrix ◽  
The Impact ◽  
Interface Bond

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

scholarly journals Self-Reinforced Nylon 6 Composite for Smart Vibration Damping

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1235
Author(s):  
Bidita Salahuddin ◽  
Rahim Mutlu ◽  
Tajwar A. Baigh ◽  
Mohammed N. Alghamdi ◽  
Shazed Aziz
Keyword(s):  
Matrix Material ◽  
Nylon 6 ◽  
Vibration Damping ◽  
Vibration Energy ◽  
Damping Factor ◽  
Passive Vibration Control ◽  
Reinforced Composite ◽  
Coiled Structure ◽  
The Matrix ◽  
3D Printed

Passive vibration control using polymer composites has been extensively investigated by the engineering community. In this paper, a new kind of vibration dampening polymer composite was developed where oriented nylon 6 fibres were used as the reinforcement, and 3D printed unoriented nylon 6 was used as the matrix material. The shape of the reinforcing fibres was modified to a coiled structure which transformed the fibres into a smart thermoresponsive actuator. This novel self-reinforced composite was of high mechanical robustness and its efficacy was demonstrated as an active dampening system for oscillatory vibration of a heated vibrating system. The blocking force generated within the reinforcing coiled actuator was responsible for dissipating vibration energy and increase the magnitude of the damping factor compared to samples made of non-reinforced nylon 6. Further study shows that the appropriate annealing of coiled actuators provides an enhanced dampening capability to the composite structure. The extent of crystallinity of the reinforcing actuators is found to directly influence the vibration dampening capacity.

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