Hydrothermal Ageing Mechanism of Natural Fiber Reinforced Composite in Hot Water

2012 ◽  
Author(s):  
Mengyuan Liao ◽  
Yuqiu Yang ◽  
Ying Yu ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Property ◽  
Weight Loss ◽  
Water Absorption ◽  
Weight Change ◽  
Natural Fiber ◽  
Water Environment ◽  
Hot Water ◽  
Woven Fabric ◽  
Bending Test ◽  
Reinforced Composite

As well known, sustainability issues represented by the environment and resource protection have been paid close attention nowadays. Natural fiber has been an increasing interest and promising as reinforcing fiber in polymeric composites due to its low density, cost, acceptable specific strength and biodegradation. Even though, the principle challenge for natural fibers used as reinforcement is their internal strong water-absorption ability when the exposed in wet and water environment. Long-term hydrothermal degradation behavior of Glass reinforced composite (GFRP) and jute reinforced composite (JFRP) have been discussed in previous study on the basis of the great amount of physical and mechanical testing results. As former working reported, gained water content increases linearly against the square root of aging time followed by gradual increase trend in longer duration both in JFRP and GFRP. In particularly, JFRP’s weight loss performance occurred earlier with higher value compared to GFRP. However, water absorption and weight loss mechanism, relationship between weight change and retention of mechanical property for JFRP didn’t report and illustrate clearly and extensively. Therefore, in order to figure it out comprehensively, the current study was focus on hydrothermal ageing mechanism and corresponding degraded mechanical behavior. Firstly, 2 layers of deeply dried and natural dried jute woven fabric reinforced unsaturated polyester were fabricated by hand-layup method. The cut samples were immersed into 80°C hot water bath for predetermined durations and inspected by ultrasonic wave. Afterwards, 3-point bending test with acoustic emission (AE) measurement was carried out for aged samples. The weight change mechanism, evolution of internal deterioration and mechanical property along with ageing time was investigated. The result indicated that JFRP can absorb water easily and quickly compared with GFRP owing to jute fiber’s hydroscopic nature. Weight loss was caused as a result of resin particle loss and pectin dissolution from the developed micro-crack owing to hydrothermal water environment. What’s more, internal serious deterioration occurred after 24 hours immersion leading to larger reduction of mechanical property.

The Experimental Investigation on Water Absorption Characteristics of Natural Fiber Composites

2014 ◽  
Vol 984-985 ◽  
pp. 248-252
Author(s):  
S. Vijayakumar ◽  
S. Manikandan ◽  
L. Karunamoorthy
Keyword(s):  
Water Absorption ◽  
Rice Straw ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Alkaline Treatment ◽  
Time Intervals ◽  
Synthetic Fibers ◽  
Reinforced Composite ◽  
Major Variation ◽  
Absorption Characteristics

Natural fibers are used for replacing synthetic fibers as reinforcement in various matrices. This paper is presents the fabrication and water absorption characteristics of various natural fibers reinforced composite fabricated by hand layering technique. The water absorbing capacity, diffusion and permeability of various natural fibers like rice straw, Kenaf, Coconut Spathe, Coconut Guinit reinforced composite with different dipping time intervals were analyzed. Morphological analysis was carried out on fabricated and soaked samples using scanning electron microscope. From the experimental work it is observed that coconut guinits and rice straw shows comparatively very low water absorbing capacity. Alkaline treatment of fibers doesnot have any major variation in water absorbing capacity.

An investigation into self-sensing property of hat-shaped 3D orthogonal woven composite under bending test

2018 ◽  
Vol 38 (4) ◽  
pp. 149-166 ◽  
Author(s):  
Xiaoying Cheng ◽  
Hongshui Zhou ◽  
Zhenyu Wu ◽  
Xudong Hu
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Sensor Arrays ◽  
Woven Fabric ◽  
Bending Test ◽  
Fiber Array ◽  
Reinforced Composite ◽  
Resistance Variation ◽  
Deformation Distribution ◽  
3D Orthogonal Woven

In this paper, the influence of damage and deformation on the electrical property of carbon fibers in the hat-shaped 3D orthogonal woven fabric-reinforced composite structure is studied. A method of producing parallel sensor arrays was proposed, in which the warp yarns made of carbon fibers were separated by isolated Kevlar fibers as weft yarns and Z-yarns. The sensor array unitized the self-sensing property of carbon fiber and could detect the damage and deformation distribution along the transverse direction of the composite under bending tests. Both the experiments and simulations had been conducted to analyze the mechanical and electrical responses of the carbon fiber array. By comparing the experimental results and simulation data, the method was validated and the influences of damage and deformation distribution on the resistance variation of carbon fibers were revealed.

Effects of Natural Fiber Reinforcement on Water Absorption of Compressed Stabilized Earth Blocks

2012 ◽  
Vol 2 (11) ◽  
pp. 165-167
Author(s):  
B.O .Ugwuishiwu B.O .Ugwuishiwu ◽  
◽  
B.O. Mama B.O. Mama ◽  
N. M Okoye N. M Okoye
Keyword(s):  
Water Absorption ◽  
Natural Fiber ◽  
Fiber Reinforcement ◽  
Earth Blocks

2007-P: Weight Change and Intentionality of Weight Loss Relate to Mortality Risk in the Postintervention (Years 8-16) Phase of Look AHEAD

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 2007-P
Author(s):  
RENA R. WING ◽  
JEANNE CLARK ◽  
MARK ESPELAND ◽  
JAMES O. HILL ◽  
ROBERT W. JEFFERY ◽  
...  
Keyword(s):  
Weight Loss ◽  
Mortality Risk ◽  
Weight Change ◽  
Look Ahead

Mechanical Property Studies on Flax Fiber Reinforced Basalt Powder Filled Polyester Composite

2020 ◽  
Vol 13 ◽  
Author(s):  
V. Arumugaprabu ◽  
K.Arun Prasath ◽  
S. Mangaleswaran ◽  
M. Manikanda Raja ◽  
R. Jegan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Natural Fiber ◽  
Tensile Load ◽  
Flax Fiber ◽  
Flexural Properties ◽  
Weight Percentage ◽  
Tensile Impact ◽  
Polyester Composite ◽  
Additional Support

: The objective of this research is to evaluate the tensile, impact and flexural properties of flax fiber and basalt powder filled polyester composite. Flax fiber is one of the predominant reinforcement natural fiber which possess good mechanical properties and addition of basalt powder as a filler provides additional support to the composite. The Composites are prepared using flax fiber arranged in 10 layers with varying weight percentage of the basalt powder as 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%, 25 wt.% and 30 wt.% respectively. From the results it is inferred that the composite combination 10 Layers of flax / 5 wt.%, basalt Powder absorbs more tensile load of 145 MPa. Also, for the same combination maximum flexural strength is about 60 MPa. Interestingly in the case of impact strength more energy was absorbed by 10 layers of flax and 30 wt.% of basalt powder. In addition, the failure mechanism of the composites also discussed briefly using SEM studies.

scholarly journals Characterization of a new natural fiber extracted from Corypha taliera fruit

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Taslima Ahmed Tamanna ◽  
Shah Alimuzzaman Belal ◽  
Mohammad Abul Hasan Shibly ◽  
Ayub Nabi Khan
Keyword(s):  
Tensile Strength ◽  
Natural Fiber ◽  
Natural Fibers ◽  
Morphological Characteristics ◽  
Synthetic Fiber ◽  
X Ray Diffraction ◽  
Reinforced Composite ◽  
Potential Alternative

AbstractThis study deals with the determination of new natural fibers extracted from the Corypha taliera fruit (CTF) and its characteristics were reported for the potential alternative of harmful synthetic fiber. The physical, chemical, mechanical, thermal, and morphological characteristics were investigated for CTF fibers. X-ray diffraction and chemical composition characterization ensured a higher amount of cellulose (55.1 wt%) content and crystallinity (62.5%) in the CTF fiber. The FTIR analysis ensured the different functional groups of cellulose, hemicellulose, and lignin present in the fiber. The Scherrer’s equation was used to determine crystallite size 1.45 nm. The mean diameter, specific density, and linear density of the CTF fiber were found (average) 131 μm, 0.86 g/cc, and 43 Tex, respectively. The maximum tensile strength was obtained 53.55 MPa for GL 20 mm and Young’s modulus 572.21 MPa for GL 30 mm. The required energy at break was recorded during the tensile strength experiment from the tensile strength tester and the average values for GL 20 mm and GL 30 mm are 0.05381 J and 0.08968 J, respectively. The thermal analysis ensured the thermal sustainability of CTF fiber up to 230 °C. Entirely the aforementioned outcomes ensured that the new CTF fiber is the expected reinforcement to the fiber-reinforced composite materials.

Manufacturing a carbon/epoxy NACA 23018 airfoil skin using a circular braiding machine: experimental and numerical study

2021 ◽  
pp. 152808372199377
Author(s):  
Jalil Hajrasouliha ◽  
Mohammad Sheikhzadeh
Keyword(s):  
Numerical Study ◽  
Filament Winding ◽  
Bending Test ◽  
Elastic Response ◽  
Manufacturing Processes ◽  
Fiber Reinforced Composite ◽  
Four Point Bending ◽  
Reinforced Composite ◽  
Four Point Bending Test ◽  
Meso Scale

In the interest of reducing the weight and also cost of blade skins, various automatic preform manufacturing processes were developed including tape laying, filament winding and braiding. Among them, the circular braiding process was found to be an efficient method in producing seamless preforms on mandrels with various geometries. In this regard, an attempt was made to produce a carbon fiber reinforced composite with the shape of NACA 23018 airfoil using a circular braiding machine. Thus, suitable wooden mandrels were manufactured using NACA 23018 airfoil coordinates, which were obtained by assuming the perimeter of 20 cm. Furthermore, both biaxially and triaxially braided preforms were produced and subsequently impregnated with epoxy resin through an appropriate fabrication method. To assess their performance, four-point bending test was carried out on samples. Ultimately, the elastic response of braided composite airfoils was predicted using a meso-scale finite element modeling and was validated with experimental results.

scholarly journals Depression-related weight change and incident diabetes in a community sample

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Eva Graham ◽  
Tristan Watson ◽  
Sonya S. Deschênes ◽  
Kristian B. Filion ◽  
Mélanie Henderson ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Weight Loss ◽  
Weight Gain ◽  
Weight Change ◽  
Short Form ◽  
Community Sample ◽  
Overweight And Obesity ◽  
Community Dwelling ◽  
Increased Risk

AbstractThis cohort study aimed to compare the incidence of type 2 diabetes in adults with depression-related weight gain, depression-related weight loss, depression with no weight change, and no depression. The study sample included 59,315 community-dwelling adults in Ontario, Canada. Depression-related weight change in the past 12 months was measured using the Composite International Diagnostic Interview—Short Form. Participants were followed for up to 20 years using administrative health data. Cox proportional hazards models compared the incidence of type 2 diabetes in adults with depression-related weight change and in adults with no depression. Adults with depression-related weight gain had an increased risk of type 2 diabetes compared to adults no depression (HR 1.70, 95% CI 1.32–2.20), adults with depression-related weight loss (HR 1.62, 95% CI 1.09–2.42), and adults with depression with no weight change (HR 1.39, 95% CI 1.03–1.86). Adults with depression with no weight change also had an increased risk of type 2 diabetes compared to those with no depression (HR 1.23, 95% CI 1.04–1.45). Associations were stronger among women and persisted after adjusting for attained overweight and obesity. Identifying symptoms of weight change in depression may aid in identifying adults at higher risk of type 2 diabetes and in developing tailored prevention strategies.

scholarly journals Patterns of Weight Change in Aging and Dying

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 491-491
Author(s):  
Stephen Thielke
Keyword(s):  
Older Adults ◽  
Weight Loss ◽  
Risk Factor ◽  
Weight Change ◽  
Population Level ◽  
Chronological Age ◽  
Average Weight ◽  
Remaining Life ◽  
Entire Cohort ◽  
History Of

Abstract Little research has characterized the natural history of weight change in older adults. Different changes may occur during aging and dying. We analyzed 18 years of weight measures from a cohort of 736,361 Veterans, all of whom had died at age 70 or older. We produced summary measures that accounted for both chronological age and number of years before death. Several clear population-level trends appeared. (1) The average weight of the sample declined across all ages at a rate of about 0.18 BMI points per year. (2) Starting about seven years before death, the amount of loss began to accelerate, reaching a decline of 0.75 BMI points in the year before death. (3) Changes in weight relative to years of remaining life were independent of chronologic age. People who died at age 70 experienced, on average, the same type and duration of terminal decline as did those who died at age 95. (4) The dying process involved a cumulative loss of about 1.3 BMI points. (5) The distribution of weights during advancing age both declined and narrowed. (6) Disproportionate deaths occurred at the lower BMI ranges (below a BMI of 24), and especially below 18, regardless of age. (7) The finding in #5 is explained by the entire cohort losing weight, with death of the thinnest members. These findings argue for examining survival time in studies of weight change. They indicate that weight loss may be a natural part of dying, rather than a risk factor for it.

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