Static and Fatigue Strength of Resin Transfer Molded Composites

2002 ◽  
Author(s):  
Youssef Hamidi ◽  
Levent Aktas ◽  
J. David Bladwin ◽  
M. Cengiz Altan
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Volume Fraction ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Fiber Content ◽  
Fiber Volume ◽  
Neat Polymer ◽  
Volume Fractions ◽  
Structural Applications

Fiber reinforced polymer composites are preferred in many structural applications for their ease of production and high specific strengths. Although fatigue loading is commonly encountered in structural applications, behavior of composites under cyclic loading is less understood compared to fatigue behavior of more conventional metals and their alloys. In this work, the response of resin transfer molded (RTM) glass/epoxy composites to static tensile and fatigue loading is investigated. Center-gated, disk shaped composites are fabricated using EPON 815C epoxy resin and EPICURE 3282 curing agent. A randomly oriented, planar glass fiber preform with 0.459kg/m2 surface density is used as the reinforcement material. Two and six layers of preforms are used to achieve 7.9 and 28.9% fiber volume fractions respectively. In addition, neat polymer parts are molded without performs to study the effect of fiber content on the tensile and fatigue behavior. Initially, ultimate tensile strength (UTS) and stiffness for three different fiber volume fractions (i.e., 0, 7.9, and 28.9%) are reported. Then, fatigue tests are conducted for stress level (σmax/UTS) of 0.5 and stress ratio (σmax/σmin) of 0.1 at a test frequency of 10 Hz. Loss of stiffness and cycles to failure are the two fatigue properties investigated. As the fiber volume fraction increased from 7.9 to 28.9%, the ultimate tensile strength and stiffness increased by 140 and 100%, respectively. During fatigue loading, the stiffness gradually dropped by approximately 13% for 7.9% and 28.9% fiber volume fractions. However, neat polymer samples did not show considerable decrease in stiffness during cycling. It is also shown that the number of cycles before failure significantly increased with the fiber content.

Performance of Bamboo Fiber Reinforced Composites: Mechanical Properties

2021 ◽  
Vol 879 ◽  
pp. 284-293
Author(s):  
Norliana Bakar ◽  
Siew Choo Chin
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Vinyl Ester ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Bamboo Fiber ◽  
Synthetic Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Volume Fractions

Fiber Reinforced Polymer (FRP) made from synthetic fiber had been widely used for strengthening of reinforced concrete (RC) structures in the past decades. Due to its high cost, detrimental to the environment and human health, natural fiber composites becoming the current alternatives towards a green and environmental friendly material. This paper presents an investigation on the mechanical properties of bamboo fiber reinforced composite (BFRC) with different types of resins. The BFRC specimens were prepared by hand lay-up method using epoxy and vinyl-ester resins. Bamboo fiber volume fractions, 30%, 35%, 40%, 45% and 50% was experimentally investigated by conducting tensile and flexural test, respectively. Results showed that the tensile and flexural strength of bamboo fiber reinforced epoxy composite (BFREC) was 63.2% greater than the bamboo fiber reinforced vinyl-ester composite (BFRVC). It was found that 45% of bamboo fiber volume fraction on BFREC exhibited the highest tensile strength compared to other BFRECs. Meanwhile, 40% bamboo fiber volume fraction of BFRVC showed the highest tensile strength between bamboo fiber volume fractions for BFRC using vinyl-ester resin. Studies showed that epoxy-based BFRC exhibited excellent results compared to the vinyl-ester-based composite. Further studies are required on using BFRC epoxy-based composite in various structural applications and strengthening purposes.

scholarly journals Experimental Investigation on the Quasi-Static Tensile Capacity of Engineered Cementitious Composites Reinforced with Steel Grid and Fibers

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2666
Author(s):  
Li ◽  
Liu ◽  
Wu ◽  
Wu ◽  
Wu
Keyword(s):  
Tensile Strength ◽  
Energy Dissipation ◽  
Ultimate Tensile Strength ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Kevlar Fiber ◽  
Static Tensile ◽  
Pva Fiber

An engineered cementitious composite (ECC) was reinforced with a steel grid and fibers to improve its tensile strength and ductility. A series of tensile tests have been carried out to investigate the quasi-static tensile capacity of the reinforced ECC. The quasi-static tensile capacities of reinforced ECCs with different numbers of steel-grid layers, types of fibers (Polyvinyl alcohol (PVA) fiber, KEVLAR fiber, and polyethylene (PE) fiber), and volume fractions of fibers have been tested and compared. It is indicated by the test results that: (1) On the whole, the steel grid-PVA fiber and steel grid-KEVLAR fiber reinforced ECCs have high tensile strength and considerable energy dissipation performance, while the steel grid-PE fiber reinforced ECC exhibits excellent ductility. (2) The ultimate tensile strength of the reinforced ECC can be improved by the addition of steel grids. The maximal peak tensile stress increase is about 50–95% or 140–190% by adding one layer or two layers of steel grid, respectively. (3) The ultimate tensile strength of the reinforced ECC can be enhanced with the increase of fiber volume fraction. For a certain kind of fiber, a volume fraction between 1.5% and 2% grants the reinforced ECC the best tensile strength. Near the ultimate loading point, the reinforced ECC exhibits strain hardening behavior, and its peak tensile stress increases considerably. The energy dissipation performance of the reinforced ECC can also be remarkably enhanced by such an increase in fiber volume fraction. (4) The ductility of the steel grid-PVA fiber reinforced ECC can be improved by the addition of steel grids and the increase of fiber volume fraction. The ductility of the steel grid-KEVLAR fiber reinforced ECC can be improved by the addition of steel grids alone. The ductility and energy dissipation performance of the steel grid-PE fiber reinforced ECC can be improved with the increase of fiber volume fraction alone. A mechanical model for the quasi-static initial and ultimate tensile strength of the steel grid-fiber reinforced ECC is proposed. The model is validated by the test data from the quasi-static tension experiments on the steel grid-PE fiber reinforced ECC.

Mechanical Behavior of a Ni/TiC Microlaminate Under Static and Fatigue Loading

1996 ◽  
Vol 434 ◽  
Author(s):  
Y. C. Her ◽  
P. C. Wang ◽  
J.-M. Yang ◽  
R. F. Bunshah
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Mechanical Behavior ◽  
Layer Thickness ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Stiffness Reduction ◽  
Static And Cyclic Loading ◽  
The Relationship

AbstractThe mechanical behavior and damage mechanisms of the Ni/TiC microlaminate composites under static and cyclic loading were investigated. The relationship between the ultimate tensile strength and the layer thickness at both room temperature and 600°C was studied. The fatigue life and the evolution of the stiffness reduction under various maximum applied stress levels were determined. The results revealed that the ultimate tensile strength linearly increased as the laminate layer thickness decreased. Also, the microlaminate exhibited a non-progressive fatigue behavior.

scholarly journals Effects of Polypropylene Fiber Content on Strength and Workability Properties of Concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 7-12 ◽  
Author(s):  
Arsalan Hasan ◽  
Nyazi Maroof ◽  
Yassin Ibrahim
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Volume Fraction ◽  
Dynamic Properties ◽  
Polypropylene Fiber ◽  
Plain Concrete ◽  
Fiber Content ◽  
Fiber Volume ◽  
Concrete Mix ◽  
Absorption Percentage

Low tensile strength of plain concrete is due to the inherent presence of microcracks due to drying shrinkage occurrences or other causes of volume changes in concrete. The addition of a proper amount of fibers to concrete would act as crack arrester thus improves its static or dynamic properties. In this paper, the concrete with different amount of polypropylene fiber was investigating to find out the fibers effect on its fresh and mature properties. A plain concrete mix (reference mix) prepared for comparison purposes. Nine concrete mixes were prepared with different fiber volume fraction (FVF) ranging from 0.06% to 2.16%. It has been found out that the fiber content of the concrete mix will increase compressive, splitting, and flexural strengths of the concrete at the age of 28 days. The strengths increased and reached their maximum value at a corresponding (FVF) of about 0.36%. In comparison with the reference mix, the increase in the maximum compressive strength was about 18%, while the increase in maximum splitting tensile strength was about 16% and the increase in flexural strength was about 14%. When the fiber content increased beyond the mentioned 0.36% volume fraction: The concrete strengths started to decrease due to high volume fiber interface with the cohesiveness of the concrete matrix causing difficulty in concrete compaction with lowering its workability. At fiber (FVF) of 0.96%, the concrete slump value became zero. Thus, forced vibration needed for the compaction. For each mature concrete mix density and water absorption percentage were measured. It has been noticed that with an increase of fiber dosage in the concrete mix its density will decrease leading to contrarily an increase in the water absorption percentage. This was due to an increase in air void in the concrete due to the reduction in the workability of the concrete.

scholarly journals Tensile Mechanical Properties and Failure Modes of a Basalt Fiber/Epoxy Resin Composite Material

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jingjing He ◽  
Junping Shi ◽  
Xiaoshan Cao ◽  
Yifeng Hu
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Fiber Volume Fraction ◽  
Failure Modes ◽  
Volume Fraction ◽  
Basalt Fiber ◽  
Orientation Angle ◽  
Fiber Volume ◽  
Fiber Clustering ◽  
Fiber Orientation Angle

Uniaxial tensile tests of basalt fiber/epoxy (BF/EP) composite material with four different fiber orientations were conducted under four different fiber volume fractions, and the variations of BF/EP composite material failure modes and tensile mechanical properties were analyzed. The results show that when the fiber volume fraction is constant, the tensile strength, elastic modulus, and limiting strain of BF/EP composite material all decrease with increasing fiber orientation angle. When the fiber orientation angle is constant, the tensile strength, elastic modulus, and limiting strain of BF/EP composite material all increase with increasing fiber volume fraction. A certain degree of fiber clustering appears in the epoxy resin when the basalt fiber volume fraction is >1.2%. The fiber equidistribution coefficient and clustering fiber content were used to characterize the basalt fiber clustering effect. With the increase of fiber volume fraction, the clustering fiber content gradually increased, but the fiber equidistribution coefficient decreased. Meanwhile, based on Tsai theory, a geometric model and a tensile mechanical model of the clustering fiber are established. By considering the fiber clustering effect, the BF/EP composite material tensile strength is calculated, and the calculated values are close to the experimental results.

scholarly journals Tensile Behavior Characteristics of High-Performance Slurry-Infiltrated Fiber-Reinforced Cementitious Composite with Respect to Fiber Volume Fraction

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3335 ◽  
Author(s):  
Seungwon Kim ◽  
Dong Joo Kim ◽  
Sung-Wook Kim ◽  
Cheolwoo Park
Keyword(s):  
Tensile Strength ◽  
Energy Absorption ◽  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Absorption Capacity ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Energy Absorption Capacity ◽  
Direct Tensile ◽  
Direct Tensile Strength

Concrete has high compressive strength, but low tensile strength, bending strength, toughness, low resistance to cracking, and brittle fracture characteristics. To overcome these problems, fiber-reinforced concrete, in which the strength of concrete is improved by inserting fibers, is being used. Recently, high-performance fiber-reinforced cementitious composites (HPFRCCs) have been extensively researched. The disadvantages of conventional concrete such as low tensile stress, strain capacity, and energy absorption capacity, have been overcome using HPFRCCs, but they have a weakness in that the fiber reinforcement has only 2% fiber volume fraction. In this study, slurry infiltrated fiber reinforced cementitious composites (SIFRCCs), which can maximize the fiber volume fraction (up to 8%), was developed, and an experimental study on the tensile behavior of SIFRCCs with varying fiber volume fractions (4%, 5%, and 6%) was carried out through direct tensile tests. The results showed that the specimen with high fiber volume fraction exhibited high direct tensile strength and improved brittleness. As per the results, the direct tensile strength is approximately 15.5 MPa, and the energy absorption capacity was excellent. Furthermore, the bridging effect of steel fibers induced strain hardening behavior and multiple cracks, which increased the direct tensile strength and energy absorption capacity.

Experiment Investigation on Mechanical Property of Glass Fiber Reinforced Concrete

2014 ◽  
Vol 915-916 ◽  
pp. 784-787
Author(s):  
Yan Lv
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Flexural Strength ◽  
Glass Fiber ◽  
Volume Fraction ◽  
Plain Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Glass Fiber Reinforced

Based on the mechanical properties experiment of the glass fiber reinforced concrete with 0%0.6%0.8% and 1% glass fiber volume fraction, the mechanics property such as tensile strength, compressive strength, flexural strength and flexural elasticity modulus are analyzed and compared with the plain concrete when the kinds of fiber content changes. The research results show that the effect of tensile strength and flexural strength can be improved to some extent, which also can serve as a reference or basis for further improvement and development the theory and application of the glass fiber reinforced concrete.

High Temperature Properties of Refractory Intermetallics

1990 ◽  
Vol 213 ◽  
Author(s):  
D.L. Anton ◽  
E. Hartford CT ◽  
D.M. Shah ◽  
Pratt Whitney ◽  
E. Hartford CT
Keyword(s):  
Solid Solution ◽  
Tensile Strength ◽  
High Temperature ◽  
Low Temperature ◽  
Ultimate Tensile Strength ◽  
Melting Temperatures ◽  
Structural Applications ◽  
Oxidation Resistant ◽  
Low Temperature Toughness ◽  
Niobium Solid Solution

AbstractOn the basis of creep strength, ultimate tensile strength and oxidation resistance, seven intermetallic compounds with melting temperatures above 1600°C have been selected as possible candidate materials for high temperature structural applications in advanced aero-turbines. These compounds, Nb3Al, Cr3Si, Co2Nb, Cr2Nb, MoSi2, Mo5Si3 and Nb2Al, have been evaluated and their properties reported herein. All seven of the compounds displayed excellent creep resistance at 1200°C with Mo5Si3 and Nb2Al being the strongest. Nb3Al, with the precipitation of the niobium solid solution displayed the greatest low temperature toughness. The greatest ultimate tensile strengths were observed for Co2Nb and MoSi2, while MoSi2 was by far the most oxidation resistant.

Effect of Fiber Content on Void Morphology in Resin Transfer Molded E-Glass/Epoxy Composites

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Youssef K. Hamidi ◽  
Sudha Dharmavaram ◽  
Levent Aktas ◽  
M. Cengiz Altan
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Void Formation ◽  
Areal Density ◽  
Fiber Content ◽  
Epoxy Composites ◽  
Formation Mechanisms ◽  
Liquid Composite Molding ◽  
Fiber Volume ◽  
Composite Molding

Effect of fiber volume fraction on occurrence, morphology, and spatial distribution of microvoids in resin transfer molded E-glass/epoxy composites is investigated. Three disk-shaped center-gated composite parts containing 8, 12, and 16 layers of randomly-oriented, E-glass fiber perform are molded, yielding 13.5%, 20.5%, and 27.5% fiber volume fractions. Voids are evaluated by microscopic image analysis of the samples obtained along the radius of these disk-shaped composites. The number of voids is found to decrease moderately with increasing fiber content. Void areal density decreased from 10.5 voids/mm2 to 9.5 voids/mm2 as fiber content is increased from 13.5% to 27.5%. Similarly, void volume fraction decreased from 3.1% to 2.5%. Increasing fiber volume fraction from 13.5% to 27.5% is found to lower the contribution of irregularly-shaped voids from 40% of total voids down to 22.4%. Along the radial direction, combined effects of void formation by mechanical entrapment and void mobility are shown to yield a spatially complex void distribution. However, increasing fiber content is observed to affect the void formation mechanisms as more voids are able to move toward the exit vents during molding. These findings are believed to be applicable not only to resin transfer molding but generally to liquid composite molding processes.

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