scholarly journals Effect of Short Fiber Reinforcement on Mechanical Properties of Hybrid Phenolic Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Sembian Manoharan ◽  
Bhimappa Suresha ◽  
Govindarajulu Ramadoss ◽  
Basavaraj Bharath
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Loss Modulus ◽  
Basalt Fiber ◽  
Barium Sulphate ◽  
Dynamic Mechanical Properties ◽  
Damping Factor ◽  
X Ray ◽  
Weight Percentage ◽  
Dynamic Mechanical

Fiber plays an important role in determining the hardness, strength, and dynamic mechanical properties of composite material. In the present work, enhancement of viscoelastic behaviour of hybrid phenolic composites has been synergistically investigated. Five different phenolic composites, namely, C1, C2, C3, C4, and C5, were fabricated by varying the weight percentage of basalt and aramid fiber, namely, 25, 20, 15, 10, and 5% by compensating with barium sulphate (BaSO4) to keep the combined reinforcement concentration at 25 wt%. Hardness was measured to examine the resistance of composites to indentation. The hardness of phenolic composites increased from 72.2 to 85.2 with increase in basalt fiber loading. Composite C1 (25 wt% fiber) is 1.2 times harder than composite C5. Compression test was conducted to find out compressive strength of phenolic composites and compressive strength increased with increase in fiber content. Dynamic mechanical analysis (DMA) was carried out to assess the temperature dependence mechanical properties in terms of storage modulus (E′), loss modulus (E′′), and damping factor (tan δ). The results indicate great improvement of E′ values and decrease in damping behaviour of composite upon fiber addition. Further X-ray powder diffraction (XRD) and energy-dispersive X-ray (EDX) analysis were employed to characterize the friction composites.

scholarly journals Dynamic Mechanical Properties of Hybrid Layered Silicates/Kaolin Geopolymer Filler in Epoxy Composites

2017 ◽  
Vol 54 (3) ◽  
pp. 543-545 ◽  
Author(s):  
Yusrina Mat Daud ◽  
Kamarudin Hussin ◽  
Azlin Fazlina Osman ◽  
Che Mohd Ruzaidi Ghazali ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Layered Silicates ◽  
Epoxy Composites ◽  
Damping Factor ◽  
Dynamic Mechanical

Preparation epoxy based hybrid composites were involved kaolin geopolymer filler, organo-montmorillonite at 3phr by using high speed mechanical stirrer. A mechanical behaviour of neat epoxy, epoxy/organo-montmorillonite and its hybrid composites containing 1-8phr kaolin geopolymer filler was studied upon cyclic deformation (three-point flexion mode) as the temperature is varies. The analysis was determined by dynamic mechanical analysis (DMA) at frequency of 1.0Hz. The results then expressed in storage modulus (E�), loss modulus (E�) and damping factor (tan d) as function of temperature from 40 oC to 130oC. Overall results indicated that E�, E�� and Tg increased considerably by incorporating optimum 1phr kaolin geopolymer in epoxy organo-montmorillonite hybrid composites.

scholarly journals Dynamic mechanical analysis of nylon 6 fiber-reinforced acrylonitrile butadiene rubber composites

2021 ◽  
pp. 096739112110461
Author(s):  
C Rajesh ◽  
P Divia ◽  
S Dinooplal ◽  
G Unnikrishnan ◽  
E Purushothaman
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Damping Factor ◽  
Butadiene Rubber ◽  
Bonding Agents ◽  
Fiber Loading ◽  
Dynamic Mechanical ◽  
Acrylonitrile Butadiene Rubber

Dynamic mechanical properties of polymeric materials are of direct relevance to a range of unique polymer applications. The aim of the study is to investigate the dynamic mechanical properties of composites of short nylon 6 fiber with acrylonitrile butadiene rubber (NBR). The storage modulus (G′), loss modulus (G″), and the damping factor (tan δ) have been analyzed with reference to the effects of fiber loading, curing systems, and bonding agents over a range of temperature and at varying frequencies. The storage modulus increases with increment in fiber loading, whereas loss modulus and damping factor decrease. The glass transition temperature shifts to higher temperature upon increment in fiber loading. Dicumyl peroxide (DCP)–cured composites show higher storage modulus and lower damping than the corresponding sulfur-cured one. The addition of hexa-resorcinol and phthalic anhydride as bonding agents enhances the dynamic mechanical properties of the composites. The experimental results have been evaluated by comparing with Einstein, Guth, and Nielsen models.

scholarly journals Effect of Basalt Fiber Addition on Static-Dynamic Mechanical Behaviors and Microstructure of Stabilized Soil Compositing Cement and Fly Ash

2019 ◽  
Vol 2019 ◽  
pp. 1-20 ◽  
Author(s):  
Ziming Cao ◽  
Qinyong Ma ◽  
Hongwei Wang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Basalt Fiber ◽  
Dynamic Mechanical Properties ◽  
Fiber Content ◽  
Dynamic Mechanical ◽  
Stabilized Soil ◽  
Dynamic Compressive Strength

The purpose of this article is to evaluate the influence of basalt fiber content on the static-dynamic mechanical properties and microstructure of cement-fly ash-stabilized soil. The optimum mixed contents of cement and fly ash were obtained from the results of a series of physical and mechanical experiments. Based on the optimum mixed contents of cement and fly ash, the static-dynamic mechanical performances and microstructure of cement-fly ash-stabilized soil reinforced with basalt fiber were studied by means of the unconfined compression test, dynamic compression test (namely, SHPB test), and SEM test. The results demonstrated that the addition of basalt fiber in cement-fly ash-stabilized soil significantly enhanced the static-dynamic mechanical properties of stabilized soil. With basalt fiber content varying from 0% to 1.2%, the unconfined compressive strength, dynamic compressive strength, dynamic increase factor, and specific energy absorption of stabilized soil showed an upward trend first and a downward trend subsequently. The unconfined compressive strength, dynamic compressive strength, and energy absorption ability have a maximum improvement under the optimum basalt fiber content of 0.6%. In addition, the inclusion of basalt fiber can change the failure pattern of cement-fly ash-stabilized soil. The fractal dimension of broken fragments decreased gradually with the increasing basalt fiber content and increased correspondingly with the increasing impact loading pressure. With the basalt fiber content of 0.6%, a stable internal space structure produced inside stabilized soil. However, there are many fiber-fiber weak interfaces that appeared inside stabilized soil under the basalt fiber content of 1.2%. The microstructural observations can be considered as the good interpretations to verify the macroscopic mechanical characteristics.

Partial replacement of synthetic fibres by natural fibres in hybrid composites and its effect on monotonic properties

2019 ◽  
pp. 152808371987884 ◽  
Author(s):  
Suhad D Salman
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Partial Replacement ◽  
Damping Factor ◽  
Jute Fibre ◽  
Carbon Fibres ◽  
Dynamic Mechanical ◽  
Increasing Temperature

Owing to the high cost of carbon fibres and a necessity for finding alternatives that environmentally friendly, a portion of carbon fibres was substituted by woven jute fibre, with various stacking sequences for military applications. Hot press was used to fabricate the composite and hybrid samples of jute/carbon fibres reinforced polyvinyl butyral film using as a layer. Dynamic mechanical experiments (DMA) were conducted with more focus on the stacking sequences of jute and carbon, with increasing temperature. Results showed that the carbon/jute/carbon (H1) hybrid has the highest storage modulus and loss modulus values compared with other hybrids. Significantly, placing woven jute fibre at the outer layers and carbon fibres at the inner layers provided lower dynamic mechanical properties than that of the hybrids with placing jute at the inner layers. Besides, the damping factor shifts to higher temperatures by hybridization of jute fibres compared with carbon composite. Additionally, glass transition temperature (Tg) obtained from the damping curve and loss modulus exhibits a temperature between 129 and 180℃ for all composites, in withstanding dynamic loads. The dynamic mechanical properties were observed to be decreased with increasing temperature for all laminated composites. From results, it could be deduced that it is possible to reduce amount of carbon fibres in different composites industries with woven jute, thus providing less both cost and harmful environment.

scholarly journals X-ray Photoelectron Spectroscopic Analysis of Modified MWCNT and Dynamic Mechanical Properties of E-beam Cured Epoxy Resins with the MWCNT

2009 ◽  
Vol 10 (4) ◽  
pp. 314-319 ◽  
Author(s):  
Young-Seak Lee ◽  
Ji-Sun Im ◽  
Seok-Min Yun ◽  
Young-Chang Nho ◽  
Phil-Hyun Kang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resins ◽  
Spectroscopic Analysis ◽  
Dynamic Mechanical Properties ◽  
X Ray ◽  
Dynamic Mechanical

scholarly journals Research on the Dynamic Mechanical Properties and Energy Dissipation of Expansive Soil Stabilized by Fly Ash and Lime

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Sheng-quan Zhou ◽  
Da-wei Zhou ◽  
Yong-fei Zhang ◽  
Wei-jian Wang ◽  
Dongwei Li
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Expansive Soil ◽  
Dynamic Mechanical Properties ◽  
Test Results ◽  
Absorbed Energy ◽  
Dynamic Mechanical ◽  
Stabilized Soil ◽  
Dynamic Compressive Strength

To probe into the dynamic mechanical properties of expansive soil stabilized by fly ash and lime under impact load, the split-Hopkinson pressure bar (SHPB) test was carried out in this study. An analysis was made on the dynamic mechanical property and final fracture morphology of stabilized soil, and the failure mechanism was also explored from the perspective of energy dissipation. According to the test results, under the impact pressure of 0.2 MPa, plain soil and pure fly ash-stabilized soil exhibit strong plasticity. After the addition of lime, the stabilized soil shows obvious brittle failure. The dynamic compressive strength and absorbed energy of stabilized soil first increase and then decrease with the change of mix proportions. Both the dynamic compressive strength and the absorbed energy reach the peak value at the content of 20% fly ash and 5% lime (20% F + 5% L). In the process of the test, most of the incident energy is reflected back to the incident bar. The absorbed energy of stabilized soil increases linearly with the rise of dynamic compressive strength, while the absorbed energy is negatively correlated with the fractal dimension. The fractal dimension of pore morphology of the plain soil is lower than that of the fly ash-lime combined stabilized soil when it comes to the two different magnification ratios. The test results indicate that the modifier content of 20% F + 5% L can significantly improve the dynamic mechanical properties of the expansive soil.

scholarly journals Influence of Thermally-Accelerated Aging on the Dynamic Mechanical Properties of HTPB Coating and Crosslinking Density-Modified Model for the Payne Effect

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 403 ◽  
Author(s):  
Yongqiang Du ◽  
Jian Zheng ◽  
Guibo Yu
Keyword(s):  
Mechanical Properties ◽  
Aging Time ◽  
Loss Modulus ◽  
Accelerated Aging ◽  
Crosslinking Density ◽  
Dynamic Mechanical Properties ◽  
Maximum Elongation ◽  
Solid Rocket Motor ◽  
Payne Effect ◽  
Dynamic Mechanical

Hydroxyl terminated polybutadiene (HTPB) coating is widely used in a solid rocket motor, but an aging phenomenon exists during long-term storage, which causes irreversible damage to the performance of this HTPB coating. In order to study the effect of aging on the dynamic mechanical properties of the HTPB coating, the thermally-accelerated aging test was carried out. The variation of maximum elongation and crosslinking density with aging time was obtained, and a good linear relationship between maximum elongation and crosslinking density was found by correlation analysis. The changing regularity of dynamic mechanical properties with aging time was analyzed. It was found that with the increase of aging time, Tg of HTPB coating increased, Tα, tan β and tan α decreased, and the functional relationships between the loss factor parameters and crosslinking density were constructed. The storage modulus and loss modulus of HTPB coating increased with the increase of aging time, and decreased with the increase of pre-strain. The aging enhanced the Payne effect of HTPB coating, while the pre-strain had a weakening effect. In view of the Payne effect of HTPB coating, the crosslinking density was introduced into Kraus model as aging evaluation parameter, and the crosslinking density modified models with and without pre-strain were established. The proposed models can effectively solve the problem that the Kraus model has a poor fitting effect under the condition of small strain (generally less than 1%) and on the loss modulus, which have improved the correlations between the fitting results and the test results.

Thermal stability and dynamic mechanical behavior of functional multiphase boride ceramics/epoxy composites

2019 ◽  
Vol 39 (6) ◽  
pp. 508-514
Author(s):  
Yannan He ◽  
Zhiqiang Yu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Reaction Heat ◽  
Dynamic Mechanical

Abstract The thermal and dynamic mechanical properties of epoxy composites filled with zirconium diboride/nano-alumina (ZrB2/Al2O3) multiphase particles were investigated by means of differential scanning calorimetry, dynamic thermo-mechanical analysis, and numerical simulation. ZrB2/Al2O3 particles were surface organic functional modified by γ-glycidoxypropyltrimethoxysilane for the improvement of their dispersity in epoxy matrix. The results indicated that the curing exotherm of epoxy resin decreased significantly due to the addition of ZrB2/Al2O3 multiphase particles. In comparison to the composites filled with unmodified particles, the modified multiphase particles made the corresponding filling composites exhibit lower curing reaction heat, lower loss modulus, and higher storage modulus. Generally speaking, the composites filled with 5 wt% modified multiphase particles presented the best thermal stability and thermo-mechanical properties due to the better filler-matrix interfacial compatibility and the uniform dispersity of modified particles. Finite element analysis also suggested that the introduction of modified ZrB2/Al2O3 multiphase particles increased the stiffness of the corresponding composites.

scholarly journals Comparative Analysis of Static and Dynamic Mechanical Behavior for Dry and Saturated Cement Mortar

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3299 ◽  
Author(s):  
Ayyaz Mustafa ◽  
Mohamed A. Mahmoud ◽  
Abdulazeez Abdulraheem ◽  
Sarfaraz A. Furquan ◽  
Ayman Al-Nakhli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Comparative Analysis ◽  
Mechanical Behavior ◽  
Cement Mortar ◽  
Water Saturation ◽  
Dynamic Compression ◽  
Impact Resistance ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical

Deformational and breakage behaviors of concrete and cement mortar greatly influence various engineering structures, such as dams, river bridges, ports, tunnels, and offshore rig platforms. The mechanical and petrophysical properties are very sensitive to water content and are controlled by the liquid part in pore spaces to a large extent. The objective of this paper is to investigate the water saturation effect on the strength characteristics and deformability of cement mortar under two loading conditions, static and dynamic compression. A set of cement mortar samples was prepared and tested to study the mechanical behavior in dry and saturated states. The first part of the research incorporates the study of static mechanical properties for dry and brine-saturated cement mortar through uniaxial compressive strength tests (UCS). Second, drop-weight impact experiments were carried out to study the dynamic mechanical properties (impact resistance, deformation pattern, and fracture geometry) for dry and saturated cases. The comparative analysis revealed that water saturation caused substantial changes in compressive strength and other mechanical characteristics. Under static loading, water saturation caused a reduction in strength of 36%, and cement mortar tended to behave in a more ductile manner as compared to dry samples. On the contrary, under dynamic loading conditions, water saturation resulted in higher impact resistance and fracture toughness as compared to dry conditions. In addition, fractures could propagate to smaller depths as compared to dry case. The study will help resolve many civil, mining, and petroleum engineering problems where cement structures undergo static as well as dynamic compression, especially in a hydraulic environment where these structures interact with the water frequently. To the best of our knowledge, the effect of water saturation on the dynamic mechanical properties of cement mortar has not been well understood and reported in the literature.

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