A study on fiber-reinforced elastomer with a biphasic loading behavior

2012 ◽  
Vol 19 (4) ◽  
pp. 339-345
Author(s):  
Hao Huang ◽  
Chee-Ryong Joe ◽  
Dong-Uk Kim ◽  
Jehyun Lee ◽  
Heekyu Choi
Keyword(s):  
Fiber Length ◽  
Solid Mechanics ◽  
Rubber Matrix ◽  
Test Results ◽  
Fiber Reinforced ◽  
Physically Based ◽  
Nonlinear Solid Mechanics ◽  
Two Phases ◽  
Dominant Phase ◽  
Soft Elastomer

AbstractA specific fiber-reinforced elastomer (FRE) composite was formed by inserting curved fibers into a rubber matrix. This material combined the hyperelastic behavior of a soft elastomer matrix with the high stiffness character of a fibrous reinforcement. A biphasic loading property could be realized physically. Based on the guided concept, experiments were performed on the specimens of pure and fiber-reinforced silicone rubber, respectively. Test results showed that this FRE composite first experienced an elastomer-dominant phase with a large recoverable deformation and then a fiber-dominant phase with rapid increasing loading. This biphasic behavior of the developed FRE composite was also identified by the constitutive equations based on the nonlinear solid mechanics. It was further discovered that the division of the two phases could be varied with the change of curved fiber length.

Research on Static Load Tests of Damaged Bridge Strengthened with Pre-Stressed HFRP

2014 ◽  
Vol 1079-1080 ◽  
pp. 258-265
Author(s):  
Chen Ning Cai ◽  
Shan He ◽  
Li Na Liu ◽  
Shi Kun Ou
Keyword(s):  
Static Load ◽  
Flexural Rigidity ◽  
Fiber Reinforced Polymer ◽  
Test Results ◽  
Structural Members ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Load Tests

Thispaper presents an experimental study to strengthen an existing bridge usingpre-stressed carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer(GFRP) materials. The method using pre-stressed hybrid fiber reinforced polymer(HFRP) to strengthened structural members is an emerging pre-stressed strengtheningtechnology. In this study, experimental data selected from result of staticloading test conducted to hollow slabs with CFRP/GFRP has been compared with specimenswithout strengthening. Test results showed that the strengthening methoddeveloped in this study could effectively reduce the stress in hollow slab,improving the flexural rigidity and inhibiting the concrete from fracture.

On axial compressive behavior of steel fiber reinforced concrete confined by FRP

2021 ◽  
pp. 136943322098165
Author(s):  
Hossein Saberi ◽  
Farzad Hatami ◽  
Alireza Rahai
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Steel Fiber ◽  
Experimental Tests ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Test Results ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Frp Confinement

In this study, the co-effects of steel fibers and FRP confinement on the concrete behavior under the axial compression load are investigated. Thus, the experimental tests were conducted on 18 steel fiber-reinforced concrete (SFRC) specimens confined by FRP. Moreover, 24 existing experimental test results of FRP-confined specimens tested under axial compression are gathered to compile a reliable database for developing a mathematical model. In the conducted experimental tests, the concrete strength was varied as 26 MPa and 32.5 MPa and the steel fiber content was varied as 0.0%, 1.5%, and 3%. The specimens were confined with one and two layers of glass fiber reinforced polymer (GFRP) sheet. The experimental test results show that simultaneously using the steel fibers and FRP confinement in concrete not only significantly increases the peak strength and ultimate strain of concrete but also solves the issue of sudden failure in the FRP-confined concrete. The simulations confirm that the results of the proposed model are in good agreement with those of experimental tests.

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.

Synergy of fiber length and content on free vibration and damping behavior of natural fiber reinforced polyester composite beams

2014 ◽  
Vol 56 ◽  
pp. 379-386 ◽  
Author(s):  
K. Senthil Kumar ◽  
I. Siva ◽  
P. Jeyaraj ◽  
J.T. Winowlin Jappes ◽  
S.C. Amico ◽  
...  
Keyword(s):  
Free Vibration ◽  
Fiber Length ◽  
Natural Fiber ◽  
Composite Beams ◽  
Fiber Reinforced ◽  
Damping Behavior ◽  
Polyester Composite

scholarly journals Comparative behaviour of local and exotic chickens in tests of fearfulness, anxiety and cognition

2021 ◽  
Vol 41 (1) ◽  
pp. 4-15
Author(s):  
T. B. Raji ◽  
A. A. Toye
Keyword(s):  
Production System ◽  
Genetic Selection ◽  
Test Results ◽  
Extensive Management ◽  
Quantitative Genetic ◽  
Voluntary Approach ◽  
Ongoing Effort ◽  
Poultry Birds ◽  
Distress Calls ◽  
Two Phases

Behaviour affects performance and productivity of poultry birds especially chickens, some behavioural traits are advantageous in a particular production system and may be of disadvantage in another production system. The present study compared behavioural of Nigeria Local Chicken, NLC (two separate samples of 11 Yoruba Ecotype) and its Exotic counterparts (11 Broilers and 11 Pullets) by use of the Open Field (OFT), T-Maze, Forced Approach, and Voluntary Approach Tests (FAT and VAT respectively) during two phases of Growth (0-4 Weeks, and 4-8 weeks age respectively). The former group (NLC) is better adapted to extensive management in the Nigerian Guinea savannah than the latter Results showed that Yoruba NLC issued a significantly (p<0.05) higher number of distress calls than the Exotic genotypes in the OFT at age 7 and 48 days, and the NLC issued significantly more calls at 7 days age. Broilers exhibited significantly lower OFT Latency at 7 and 48 days, and Broilers traversed fewer squares and spent less time ambulating than other genotypes at 48 days age. Ina T-maze, Broilers showed significantly (p<0.05) lower exploratory behaviour than other groups (higher latency to leave the start box). In the FAT, NLC showed lower Latency to flight (p<0.05) than the Exotic genotypes. Ethological test results indicate differences in the behavioural characters exhibited by Yoruba NLC and Exotic Chickens and such differences could embody the basis of anecdotal differences in the rates of survival under extensive management conditions, and may be subjected to quantitative genetic selection in the ongoing effort to produce improved chickens that incorporate a combination of desirable traits from both Local and Exotic chickens.

scholarly journals STUDY ON FIBER FURNISHES AND FIBER MORPHOLOGICAL PROPERTIES OF COMMONLY USED INDIAN FOOD PACKAGING PAPERS AND PAPERBOARDS

2021 ◽  
Vol 55 (1-2) ◽  
pp. 125-131
Author(s):  
SWATI SOOD ◽  
CHHAYA SHARMA
Keyword(s):  
Fiber Length ◽  
Food Packaging ◽  
Morphological Properties ◽  
Test Results ◽  
Food Packages ◽  
The Mean ◽  
Fiber Components ◽  
Indian Food ◽  
Dry Fruit

Maintaining the quality of their final paper-based food packaging products at a high and constant level is a key issue for food packaging manufacturers to meet the customer demands. In the present study, in order to analyze the present status of quality of paper-based food packages in India, the fiber furnishes of different common paper- and paperboard-based food packages were studied by the Graff “C” staining test and their fiber morphological properties – by MorFi analysis. The staining test results showed that all the samples contained fiber furnish made either by the chemical or by the mechanical pulping process. Tea bags, dry fruit boxes and egg trays were made of 4 different fiber components, while sugar sachets and juice boxes contained 3 fiber components. It was also observed that all the samples contained hardwood and softwood chemical fibers. MorFi analysis determined the morphological properties of the fibers, including the mean fiber length and width, coarseness, kink angle, kinked fibers %, curl % and fines elements % in total analyzed fibers. The results thus obtained confirmed that both these techniques are very reliable and feasible tools to study the quality of paper-based food packages.

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