scholarly journals Multi-Scale Study of The Small-Strain Damping Ratio of Fiber-Sand Composites

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2476
Author(s):  
Haiwen Li ◽  
Sathwik S. Kasyap ◽  
Kostas Senetakis
Keyword(s):  
Dynamic Properties ◽  
Wide Spectrum ◽  
Damping Ratio ◽  
Polypropylene Fiber ◽  
Small Strain ◽  
Treatment Method ◽  
Fiber Content ◽  
Polypropylene Fibers ◽  
Test Results ◽  
Fiber Reinforced

The use of polypropylene fibers as a geosynthetic in infrastructures is a promising ground treatment method with applications in the enhancement of the bearing capacity of foundations, slope rehabilitation, strengthening of backfills, as well as the improvement of the seismic behavior of geo-systems. Despite the large number of studies published in the literature investigating the properties of fiber-reinforced soils, less attention has been given in the evaluation of the dynamic properties of these composites, especially in examining damping characteristics and the influence of fiber inclusion and content. In the present study, the effect of polypropylene fiber inclusion on the small-strain damping ratio of sands with different gradations and various particle shapes was investigated through resonant column (macroscopic) experiments. The macroscopic test results suggested that the damping ratio of the mixtures tended to increase with increasing fiber content. Accordingly, a new expression was proposed which considers the influence of fiber content in the estimation of the small-strain damping of polypropylene fiber-sand mixtures and it can be complementary of damping modeling from small-to-medium strains based on previously developed expressions in the regime of medium strains. Additional insights were attempted to be obtained on the energy dissipation and contribution of fibers of these composite materials by performing grain-scale tests which further supported the macroscopic experimental test results. It was also attempted to interpret, based on the grain-scale tests results, the influence of fiber inclusion in a wide spectrum of properties for fiber-reinforced sands providing some general inferences on the contribution of polypropylene fibers on the constitutive behavior of granular materials.

Experimental evaluation on engineering properties and microstructure of the high-performance fiber-reinforced mortar with low polypropylene fiber content

2021 ◽  
Vol 72 (7) ◽  
pp. 824-840
Author(s):  
Hung Vu Viet ◽  
Cuong Nguyen Tuan ◽  
Duy Nguyen Huu ◽  
Tho Ngo Nguyen Ngoc ◽  
Phuoc Huynh Trong
Keyword(s):  
High Performance ◽  
Polypropylene Fiber ◽  
Cost Effective ◽  
Fiber Content ◽  
Engineering Properties ◽  
Fiber Reinforced ◽  
Cement Mortars ◽  
High Performance Fiber ◽  
New Construction ◽  
Local Materials

Recently, high-performance fiber-reinforced mortar/concrete (HPFRM) has been researched and developed in many fields such as repair, maintenance, and new construction of infrastructure works due to its high strain capacity and tight crack width characteristics. Optimizing the design of mixture proportions and structures using HPFRM is still a complex mechanical and physical process, depending on the design principles, specific site conditions, and their local materials. This study aims to develop an HPFRM with low polypropylene fiber content by using locally available ingredients in Southern Vietnam to address the deficiencies commonly observed in traditional cement grout mortars. Three mixture proportions were prepared with different water-to-binder (w/b) ratios of 0.2, 0.25, and 0.3. Then, the performance of HPFRM was evaluated in both fresh and hardened stages. Additionally, the microstructural characteristics of each mix design were also assessed through scanning electron microscope observation. The experimental results showed that the optimum w/b of 0.25 and a fixed dosage of 0.6% polypropylene fiber produced positive impacts on the rheological, mechanical properties, and also ductility of the high-performance mortar. It was concluded that HPFRMs are promising for cost-effective and sustainable cement mortars.

scholarly journals Effect of randomly distributed polypropylene fiber reinforcement on the shear behavior of sandy soil

2019 ◽  
Vol 41 (3) ◽  
pp. 151-159
Author(s):  
Mehdi Missoum Benziane ◽  
Noureddine Della ◽  
Sidali Denine ◽  
Sedat Sert ◽  
Said Nouri
Keyword(s):  
Sandy Soil ◽  
Mechanical Characteristics ◽  
Polypropylene Fiber ◽  
Fiber Content ◽  
Polypropylene Fibers ◽  
Normal Stresses ◽  
Efficient Manner ◽  
Cost Efficient ◽  
Shear Box ◽  
Loose Medium

AbstractThe inclusions of geosynthetic materials (fibers, geomembranes and geotextiles) is a new improvement technique that ensures uniformity in the soil during construction. The use of tension resisting discreet inclusions like polypropylene fibers has attracted a significant amount of attention these past years in the improvement of soil performance in a cost-efficient manner. A series of direct shear box tests were conducted on unreinforced and reinforced Chlef sand with different contents of fibers (0, 0.25, 0.5 and0.75%) in order to study the mechanical behavior of sand reinforced with polypropylene fibers. Samples were prepared at three different relative densities 30%, 50% and 80% representing loose, medium dense and dense states,respectively, and performed at normal stresses of 50, 100 and 200 kPa. The experimental results show that the mechanical characteristics are improved with the addition of polypropylene fibers. The inclusion of randomly distributed fibers has a significant effect on the shear strength and dilation of sandy soil. The increase in strength is a function of fiber content, where it has been shown that the mechanical characteristics improve with the increase in fiber content up to 0.75%, this improvement is more significant at a higher normal stress and relative density.

A Study on Dynamic Properties of Cement-Stabilized Soils

2011 ◽  
Vol 243-249 ◽  
pp. 2050-2054 ◽  
Author(s):  
Pei Hsun Tsai ◽  
Sheng Huoo Ni
Keyword(s):  
Shear Modulus ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Confining Pressure ◽  
Test Results ◽  
Resonant Column Test ◽  
Stabilized Soil ◽  
Shearing Strain ◽  
Relationship Of ◽  
The Relationship

In this paper the dynamic property (shear modulus and damping ratio) of cement-stabilized soil is studied with using the resonant column test. The amount of cement admixed, the magnitude of confining pressure, and shearing strain amplitude are the parameters considered. Test results show that the maximum shear modulus of cement-stabilized soil increases with increasing confining pressure, the minimum damping ratio decreases with increasing confining pressure. The shear modulus of cement-stabilized soil decreases with increasing shearing strain while the damping ratio increases with increasing shearing strain. In the paper the relationship of shear modulus versus shearing strain is fitted into the Ramberg-Osgood equations using regression analysis.

Dynamic properties of carbon aerogel/epoxy nanocomposite and carbon fiber-reinforced composite beams

2017 ◽  
Vol 36 (23) ◽  
pp. 1745-1755 ◽  
Author(s):  
Tsung-Han Hsieh ◽  
Yau-Shian Huang ◽  
Ming-Yuan Shen
Keyword(s):  
Carbon Fiber ◽  
Composite Laminates ◽  
Natural Frequencies ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Carbon Aerogel ◽  
Composite Beams ◽  
Carbon Aerogels ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced

Carbon aerogels are a promising candidate for vibration insulation due to their three-dimensional networked structures interconnected with carbon nanoparticles. However, the effect of adding carbon aerogels to polymer-based composites on their dynamic properties remains unclear. In this study, an epoxy polymer matrix was modified with carbon aerogels, and this modified matrix was used to manufacture nanocomposite plates and carbon fiber-reinforced polymer composite laminates to investigate its dynamic properties. Force vibration tests were performed on cantilever beams of the composite beams. The frequency responses of the composite beams were measured experimentally and analytically; the half-power method was used to calculate the damping ratio for each vibration mode. According to the experimental results, the presence of carbon aerogel in the nanocomposites and laminates steadily increased the natural frequencies. Differences within 10% of the natural frequencies were obtained between the experimental and numerically. Furthermore, the damping ratios of the nanocomposite and laminate beams increased significantly with the increase in aerogel loading. For a nanocomposite with 0.3 wt% aerogel, a damping ratio approximately 44% greater than that of unmodified nanocomposite was obtained. The maximum damping ratio was 4.682% for the laminate with 0.5 wt% aerogel—an 88% increase compared with the unmodified laminate.

Finite Element Analysis of Dry Shrinkage of Fiber Cement Mortar

2014 ◽  
Vol 590 ◽  
pp. 312-315
Author(s):  
Wei Hong Xuan ◽  
Pan Xiu Wang ◽  
Yu Zhi Chen ◽  
Xiao Hong Chen
Keyword(s):  
Fracture Toughness ◽  
Cement Mortar ◽  
Polypropylene Fiber ◽  
Polypropylene Fibers ◽  
Test Results ◽  
Ansys Software ◽  
Element Analysis ◽  
Cement Based Materials ◽  
Dry Shrinkage ◽  
Good Agreement

The dry shrinkage deformation of polypropylene fiber mortar was analyzed by ANSYS software and compared with experiment value in this paper. The error of the calculated and experimental results in the 14 days and 28 days are 7.8% and 10.5%. It can be found that the calculated results are in good agreement with test results. The results indicate that the dry shrinkage value of polypropylene fiber mortar is lower than ordinary mortar. Adding polypropylene fibers can inhibit the process of cracking and improve the fracture toughness of cement-based materials.

Research for Dynamic Modulus and Ing Ratio of Fly Ash Modified Loess

2013 ◽  
Vol 671-674 ◽  
pp. 94-100
Author(s):  
Jun Wang ◽  
Qian Wang ◽  
Xiu Mei Zhong ◽  
Nai Wang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Dynamic Load ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Mineral Resources ◽  
Treatment Method ◽  
Dynamic Strain ◽  
Foundation Treatment ◽  
The Difference ◽  
Fly Ash Utilization

Environment pollution and exhaustion of mineral resources aroused strongly research and development of fly ash utilization. As a kind of foundation treatment method, improved by fly ash is more and more used in highway, railway roadbed construction. With the increase of speed of vehicles and vehicle load, the influence of dynamic load on the subgrade has caused people's concern. In this paper, based on fly ash modified loess, dynamic property of modified fly ash loess is discussed through the dynamic triaxial test of the unsaturation disturbed loess. The effect of the dynamic elastic modulus and the damping ratio with different amount of fly ash loess is studied. The results show that the difference of dynamic properties in dynamic load and static load is large. It mainly presents the hysteresis quality and nonlinear relationship between dynamic stress and dynamic strain. And the dynamic elasticity modulus increases with fly ash mixed amount.

Effect of Polypropylene Fiber on the Properties of Cement Mortar

2014 ◽  
Vol 919-921 ◽  
pp. 1903-1907
Author(s):  
Jun Pan ◽  
Fei Li ◽  
Xue Wu Zhang
Keyword(s):  
Reinforced Concrete ◽  
Fly Ash ◽  
Cement Mortar ◽  
Polypropylene Fiber ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Fiber Types ◽  
Fiber Reinforced ◽  
Bending Tests ◽  
Reinforced Cement

This thesis discusses the influence of fly ash content, fiber content and fiber types on the performance of fiber reinforced concrete, through the flexural and compressive tests on fiber reinforced cement mortar, and the splitting tensile and bending tests on the fiber reinforced concrete. The test result shows that the adding of fly ash can better play the enhancement of polypropylene fiber; the change of the fiber content affects the flexural strength of cement mortar and obviously improves the splitting tensile strength of the reinforced concrete; and the polypropylene fiber and steel fiber have different enhancement on cement mortar due to their qualitative differences.

scholarly journals Tension Stiffening Behavior of Polypropylene Fiber- Reinforced Concrete Tension Members

2021 ◽  
Vol 53 (2) ◽  
pp. 210209
Author(s):  
Aris Aryanto ◽  
Berto Juergen Winata
Keyword(s):  
Reinforced Concrete ◽  
Polypropylene Fiber ◽  
Fiber Reinforced Concrete ◽  
Polypropylene Fibers ◽  
Fiber Reinforced ◽  
Tension Stiffening ◽  
Cracking Behavior ◽  
Tension Members ◽  
Polypropylene Fiber Reinforced Concrete ◽  
Fiber Addition

This paper focuses on comparing the behavior of RC tension members with and without the addition of polypropylene fibers at various corrosion levels. Eight cylindrical tensile specimens were tested to evaluate their tension-stiffening and cracking behavior. The content of polypropylene fiber added into the concrete mix was the main variable (0.25%, 0.50%, 0.75%, and 1.0% of total volume). The corrosion level was varied from slight (5%), medium (10%) to severe (30%) and, like the other variables, applied only to 1.0% polypropylene fiber-reinforced concrete (PFRC) specimens. The test results showed that the fiber addition significantly increased the tension-stiffening effect but was largely unable to reduce the effect of bond degradation caused by corrosion. Moreover, the addition of polypropylene fibers was able to improve the cracking behavior in terms of crack propagation, as shown by smaller crack spacing compared to the specimen without fiber addition at the same corrosion level.

scholarly journals Enhancing Vibration Reduction on Lightweight Lower Control Arm

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Alessandro Messana ◽  
Alessandro Ferraris ◽  
Andrea G. Airale ◽  
Alessandro Fasana ◽  
Massimiliana Carello
Keyword(s):  
Mechanical Performance ◽  
Dynamic Properties ◽  
Damping Ratio ◽  
Vibration Reduction ◽  
Design Procedure ◽  
Test Results ◽  
Hybrid Lca ◽  
Original Solution ◽  
Lower Control Arm ◽  
Real Behavior

This paper describes the design procedure to enhance the damping properties of a multimaterial lightweight suspension arm for a C-segment vehicle. An innovative viscoelastic material has been used to join carbon fiber with steel that has a function of passive constrained layer damper and adhesive simultaneously. Therefore, the hybrid technology applied has been focused on reducing the LCA mass, diminishing the steel thickness, and adding a CFRP tailored cover without compromising the global mechanical performance. Particular attention has been paid to the investigation of the dynamic response in terms of vibration reduction, especially in the range of structure-borne frequencies of 0–600 Hz. Two different viscoelastic materials have been evaluated in such a way to compare their stiffness, damping, and dynamic properties. The experimental test results have been virtually correlated with a commercial FEM code to create the respective material card and predict the real behavior of the LCAs (original and hybrid). The experimental modal analysis has been performed and compared on both the arms highlighting a very good correlation between virtual and experimental results. In particular, the hybrid LCA allows an interesting improvement of damping ratio, about 3,5 times higher for each eigenmode than in the original solution.

Experimental Research on Ceramsite Concrete Beams

2012 ◽  
Vol 166-169 ◽  
pp. 708-711
Author(s):  
Chuang Du ◽  
Wen Ling Tian ◽  
Xiao Wei Wang ◽  
De Jun Wang
Keyword(s):  
Concrete Beam ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Polypropylene Fiber ◽  
Flexural Behavior ◽  
Polypropylene Fibers ◽  
Test Results ◽  
Normal Concrete ◽  
Ordinary Concrete ◽  
Cover Thickness

Six specimens, including 4 ceramsite concrete beams(one of beams mixed into the polypropylene fiber ) and 2 normal concrete beams, were tested to investigate the flexural behavior. The test results show that cracking load of ceramsite concrete beams is slightly smaller than the ordinary concrete beam and cracking load of ceramsite concrete beams has significantly improved after mixing into the polypropylene fibers. The ultimate load of ceramsite concrete beams are no less than ordinary concrete beam,and fibers have not effects on the increase of ultimate load. Load-deflection curves were compared,and the results show that stiffness of ceramsite concrete beam is less than ordinary concrete beam. Ductility of ceramsite concrete beam is poorer than ordinary concrete beam. Fibers improve the stiffness of ceramsite concrete beam. Cover thickness of concrete beam has little effect on the performance of ceramsite concrete beam.

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