Competing Weibull and stress-transfer influences on the specific tensile strength of a bonded fibrous network

2007 ◽  
Vol 67 (7-8) ◽  
pp. 1650-1658 ◽  
Author(s):  
S IANSON ◽  
W SAMPSON
Keyword(s):  
Tensile Strength ◽  
Stress Transfer ◽  
Fibrous Network

Thermal Shock Effect of Nano-TiO2 Enhanced Glass Fiber Reinforced Polymeric Composites: An Assessment on Tensile and Thermal Behavior

2020 ◽  
Vol 978 ◽  
pp. 277-283
Author(s):  
Kishore Kumar Mahato ◽  
Krishna Chaitanya Nuli ◽  
Krishna Dutta ◽  
Rajesh Kumar Prusty ◽  
Bankim Chandra Ray
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Glass Fiber ◽  
Thermal Shock ◽  
Viscoelastic Behavior ◽  
Stress Transfer ◽  
Tensile Tests ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Service Period

Fiber reinforced polymeric (FRP) composite materials are currently used in numerous structural and materials related applications. But, during their in-service period these composites were exposed to different changing environmental conditions. Present investigation is planned to explore the effect of thermal shock exposure on the mechanical properties of nanoTiO2 enhanced glass fiber reinforced polymeric (GFRP) composites. The samples were conditioned at +70°C temperature for 36 h followed by further conditioning at – 60°C temperature for the similar interval of time. In order to estimate the thermal shock influence on the mechanical properties, tensile tests of the conditioned samples were carried out at 1 mm/min loading rate. The polymer phase i.e. epoxy was modified with different nanoTiO2 content (i.e. 0.1, 0.3 and 0.5 wt. %). The tensile strength of 0.1 wt.% nanoTiO2 GFRP filled composites exhibited higher ultimate tensile strength (UTS) among all other composites. The possible reason may be attributed to the good dispersion of nanoparticles in polymer matrix corresponds to proper stress transfer during thermal shock conditioning. In order to access the variations in the viscoelastic behavior and glass transition temperature due to the addition of nanoTiO2 in GFRP composite and also due to the thermal shock conditioning, dynamic mechanical thermal analysis (DMTA) measurements were carried out. Different modes of failures and strengthening morphology in the composites were analyzed under scanning electron microscope (SEM).

scholarly journals Optimization and Prediction of Mechanical and Thermal Properties of Graphene/LLDPE Nanocomposites by Using Artificial Neural Networks

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
P. Noorunnisa Khanam ◽  
MA AlMaadeed ◽  
Sumaaya AlMaadeed ◽  
Suchithra Kunhoth ◽  
M. Ouederni ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Chemical Properties ◽  
Stress Transfer ◽  
Graphene Nanoplatelets ◽  
Mechanical And Thermal Properties ◽  
Degradation Temperature ◽  
The Matrix ◽  
Twin Screw ◽  
Artificial Neural ◽  
Artificial Neural Network Ann

The focus of this work is to develop the knowledge of prediction of the physical and chemical properties of processed linear low density polyethylene (LLDPE)/graphene nanoplatelets composites. Composites made from LLDPE reinforced with 1, 2, 4, 6, 8, and 10 wt% grade C graphene nanoplatelets (C-GNP) were processed in a twin screw extruder with three different screw speeds and feeder speeds (50, 100, and 150 rpm). These applied conditions are used to optimize the following properties: thermal conductivity, crystallization temperature, degradation temperature, and tensile strength while prediction of these properties was done through artificial neural network (ANN). The three first properties increased with increase in both screw speed and C-GNP content. The tensile strength reached a maximum value at 4 wt% C-GNP and a speed of 150 rpm as this represented the optimum condition for the stress transfer through the amorphous chains of the matrix to the C-GNP. ANN can be confidently used as a tool to predict the above material properties before investing in development programs and actual manufacturing, thus significantly saving money, time, and effort.

The Tensile Strength of Glass Yarn in Rubber and the Effects of Moisture. I

1971 ◽  
Vol 44 (4) ◽  
pp. 937-945
Author(s):  
R. A. Gregg
Keyword(s):  
Tensile Strength ◽  
Stress Transfer ◽  
Absolute Humidity ◽  
Adhesive System ◽  
Moisture Level ◽  
Moisture Loss ◽  
Strength Increase ◽  
Good Precision ◽  
High Moisture ◽  
Rubber Stock

Abstract The strength of glass tire yarn depends on its environment so that testing in rubber is necessary to determine the strength of the yarn as used. The techniques described for building and testing glass yarn-rubber composites lead to tensile values of good precision. The techniques allow specification of a standard tensile in rubber for a glass yarn. Tensiles which would exist under non-standard conditions experienced in manufacturing or use can also be determined. Tire operating temperature is one use condition covered. The techniques discriminate sufficiently to show the effects of small differences in moisture level on hot tensile strength. The rubber stock used here did not harm the tensile strength of the glass yarn. The observed tensile strength increase of the glass yarn encased in rubber as compared to air can be attributed to the stress transfer ability of the rubber and to the test piece configuration. The strength of a glass yarn-rubber composite is inversely related to the level of moisture in the composite. High moisture levels in the glass yarn and rubber stock at building and cure can hurt tensile since moisture loss from the composite can be slow. Also, high moisture level at cure may degrade the resin-adhesive system of some yarns. For this particular glass yarn under high humidity, storage at advanced temperatures and/or curing into rubber permanently damages the yarn. These observations were made under absolute humidity levels not usually encountered. The question of the extent of the humidity degradation of this type of glass yarn under practical humidities will be examined. Since the tensile loss is probably due to some degradative action on the sizing or resin, it cannot be assumed that all glass yarns will behave similarly. It will be necessary to determine the susceptibility of each glass yarn to moisture.

Fiber strength utilization in carbon/carbon composites

1993 ◽  
Vol 8 (3) ◽  
pp. 501-511 ◽  
Author(s):  
Rafael J. Zaldivar ◽  
Gerald S. Rellick ◽  
J.M. Yang
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Carbon Fibers ◽  
Fiber Strength ◽  
Stress Transfer ◽  
Carbon Matrix ◽  
Resin Matrix ◽  
Processing Conditions ◽  
Resin Matrix Composite ◽  
Fiber Matrix

The utilization of tensile strength of carbon fibers in unidirectional carbon/carbon (C/C) composites was studied for a series of four mesophase-pitch-based carbon fibers in a carbon matrix derived from a polyarylacetylene (PAA) resin. The fibers had moduli of 35, 75, 105, and 130 Mpsi. Composite processing conditions ranged from the cured-resin state to various heat-treatment temperatures (HTT's) from 1100 to 2750 °C for the C/C's. Room-temperature tensile strength and modulus were measured for the various processing conditions, and were correlated with SEM observations of fracture surfaces, fiber and matrix microstructures, and fiber/matrix interphase structures. Fiber tensile strength utilization (FSU) is defined as the ratio of apparent fiber strength in the C/C to the fiber strength in an epoxy-resin-matrix composite. Carbonization heat treatment to 1100 °C results in a brittle carbon matrix that bonds strongly with the three lower modulus fibers, resulting in matrix-dominated failure at FSU values of 24 to 35%. However, the composite with the 130-Mpsi-modulus filament had an FSU of 79%. It is attributed to a combination of tough fracture within the filament itself and a weaker fiber/matrix interface. Both factors lead to crack deflection and blunting rather than to crack propagation. The presence of a weakened interface is inferred from observations of fiber pullout. Much of the FSU of the three lower modulus fibers is recovered by HTT to 2100 or 2400 °C, principally as a result of interface weakening, which works to prevent matrix-dominated fracture. With HTT to 2750 °C, there is a drop in FSU for all the composites; it is apparently the result of a combination of fiber degradation and reduced matrix stress-transfer capability.

scholarly journals Seawater-Neutralized Bauxite Residue–Polyester Composites as Insulating Construction Materials

Buildings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 20
Author(s):  
Maissa Adi ◽  
Basim Abu-Jdayil ◽  
Fatima Al Ghaferi ◽  
Sara Al Yahyaee ◽  
Maryam Al Jabri
Keyword(s):  
Tensile Strength ◽  
Mechanical Performance ◽  
Unsaturated Polyester ◽  
Bauxite Residue ◽  
Construction Materials ◽  
Stress Transfer ◽  
Industrial Wastes ◽  
Compressive Properties ◽  
Lower Efficiency ◽  
Polyester Matrix

Bauxite residue (BR) is one of the most commonly generated industrial wastes in the world. Thus, novel techniques for its proper utilization must be urgently developed. Herein, seawater-neutralized BR–unsaturated polyester resin (UPR) composites are presented as insulating construction materials with promising mechanical performance. Composites with different BR content (0–60 vol.%) were prepared to evaluate the influence of BR content on the compressive, tensile, and flexural strengths as well as the moduli of BR–UPR composites. Experimental results revealed that adding BR particles to the polyester matrix increased the compressive properties (strength, modulus, and strain). The composites containing 20 vol.% BR showed the maximum compressive strength (108 MPa), while the composites with 30 vol.% BR exhibited the maximum compressive modulus (1 GPa). Moreover, the reduction in tensile and flexural strengths with an increase in the BR content may be attributed to the lower efficiency of stress transfer between the BR particle–polyester interface due to weak adhesion at the interface, direct contact between particles, and presence of voids or porosity. Although the tensile strength and failure stress decreased with increasing filler content, the produced composites showed outstanding tensile strength (4.0–19.3 MPa) compared with conventional insulating materials. In addition, the composite with 40 vol.% BR demonstrated a flexural strength of 15.5 MPa. Overall, BR–UPR composites showed excellent compatibility with promising mechanical properties as potential insulating construction materials.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

A TEM microscopical investigation of the magnetic domain structure of a metastable austenitic stainless steel

1994 ◽  
Vol 52 ◽  
pp. 696-697
Author(s):  
G. Fourlaris ◽  
T. Gladman
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Cold Rolling ◽  
Solution Treatment ◽  
Magnetic Domain ◽  
High Strength ◽  
Medium Carbon Steel ◽  
Magnetic Characteristics ◽  
Metastable Austenitic Stainless Steel

Stainless steels have widespread applications due to their good corrosion resistance, but for certain types of large naval constructions, other requirements are imposed such as high strength and toughness , and modified magnetic characteristics.The magnetic characteristics of a 302 type metastable austenitic stainless steel has been assessed after various cold rolling treatments designed to increase strength by strain inducement of martensite. A grade 817M40 low alloy medium carbon steel was used as a reference material.The metastable austenitic stainless steel after solution treatment possesses a fully austenitic microstructure. However its tensile strength , in the solution treated condition , is low.Cold rolling results in the strain induced transformation to α’- martensite in austenitic matrix and enhances the tensile strength. However , α’-martensite is ferromagnetic , and its introduction to an otherwise fully paramagnetic matrix alters the magnetic response of the material. An example of the mixed martensitic-retained austenitic microstructure obtained after the cold rolling experiment is provided in the SEM micrograph of Figure 1.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Curing Temperature ◽  
Test Results ◽  
Concrete Compressive Strength ◽  
Normal Concrete ◽  
Astm Method ◽  
Additive Type ◽  
Composition Variation ◽  
Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

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