Moisture absorption and hygrothermal degradation of composite laminates repaired via double scarf method

2021 ◽  
pp. 1-15
Author(s):  
Wei Feng ◽  
Fei Xu ◽  
Wei Xie
Keyword(s):  
Composite Laminates ◽  
Moisture Absorption ◽  
Hygrothermal Degradation

Effect of Moisture Absorption on the Bending Strength of CFRP

2012 ◽  
Vol 450-451 ◽  
pp. 482-485 ◽  
Author(s):  
A Ying Zhang ◽  
Di Hong Li ◽  
Dong Xing Zhang
Keyword(s):  
Moisture Content ◽  
Composite Laminates ◽  
Immersion Time ◽  
Moisture Absorption ◽  
Bending Strength ◽  
Experimental Results ◽  
Bending Tests ◽  
Three Point Bending ◽  
Damage Propagation ◽  
Effect Of Moisture

The effects of moisture content on the bending strength of T300/914 composite laminates that immersed in water for 7 days and 14 days was discussed in this paper. The three-point bending tests were conducted on the composite laminates. Experimental results reveal that the moisture content in the laminates increased with immersion time and that moisture absorption accelerated damage propagation in the composite laminates. The bending strength of the unaged, aged specimens were characterized and analyzed. Compared to the unaged specimens, the bending strength of the composite laminates immersed for 7 and 14 days decreased by 6.62% and 16.98%, respectively. The results revealed that the bending strength of the aged specimens decreased with the increasing immersion time.

Effect of Moisture Absorption on the Residual Strength after Bending Fatigue of CFRP

2011 ◽  
Vol 415-417 ◽  
pp. 2142-2145
Author(s):  
A Ying Zhang ◽  
Di Hong Li ◽  
Cheng Li Liang ◽  
Jiu Si Jia ◽  
Dong Xing Zhang
Keyword(s):  
Moisture Content ◽  
Composite Laminates ◽  
Immersion Time ◽  
Moisture Absorption ◽  
Bending Strength ◽  
Fatigue Tests ◽  
Material Strength ◽  
Bending Fatigue ◽  
Residual Properties ◽  
Effect Of Moisture

This study investigates the effect of moisture content on the residual bending strength after bending fatigue of T300/914 composite laminates immersed in water for 7 days and 14 days. Displacement-controlled three-point bending fatigue tests were conducted on specimens. After 40,000 cycles the fatigue test was stopped and the residual properties were measured on the tested specimens. Reduction in material strength was found to depend on the level of moisture content. Experimental results reveal that the moisture content in the laminates increased with immersion time. Compared to the unaged specimens, the residual bending strength after bending fatigue decreased by 6.67% and 37.04%, respectively. The residual bending strength and strength retention decreased with increased immersion time.

scholarly journals Silk as a Natural Reinforcement: Processing and Properties of Silk/Epoxy Composite Laminates

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2135 ◽  
Author(s):  
Youssef Hamidi ◽  
M. Yalcinkaya ◽  
Gorkem Guloglu ◽  
Maya Pishvar ◽  
Mehrad Amirkhosravi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Composite Laminates ◽  
Moisture Absorption ◽  
Glass Fibers ◽  
Natural Fibers ◽  
External Pressure ◽  
Silk Fabric ◽  
Interlaminar Shear ◽  
Breaking Energy

With growing environmental awareness, natural fibers have recently received significant interest as reinforcement in polymer composites. Among natural fibers, silk can potentially be a natural alternative to glass fibers, as it possesses comparable specific mechanical properties. In order to investigate the processability and properties of silk reinforced composites, vacuum assisted resin transfer molding (VARTM) was used to manufacture composite laminates reinforced with woven silk preforms. Specific mechanical properties of silk/epoxy laminates were found to be anisotropic and comparable to those of glass/epoxy. Silk composites even exhibited a 23% improvement of specific flexural strength along the principal weave direction over the glass/epoxy laminate. Applying 300 kPa external pressure after resin infusion was found to improve the silk/epoxy interface, leading to a discernible increase in breaking energy and interlaminar shear strength. Moreover, the effect of fabric moisture on the laminate properties was investigated. Unlike glass mats, silk fabric was found to be prone to moisture absorption from the environment. Moisture presence in silk fabric prior to laminate fabrication yielded slower fill times and reduced mechanical properties. On average, 10% fabric moisture induced a 25% and 20% reduction in specific flexural strength and modulus, respectively.

Characterization of Glass Fibre/Carbon Fibre Hybrid Thermoplastics Composite Laminates Fabricated by Film Stacking Method

2015 ◽  
Vol 787 ◽  
pp. 518-522 ◽  
Author(s):  
M. Mudhukrishnan ◽  
P. Hariharan ◽  
S.K. Malhotra
Keyword(s):  
Flexural Strength ◽  
Carbon Fibre ◽  
Glass Fibre ◽  
Composite Laminates ◽  
Moisture Absorption ◽  
Weight Ratio ◽  
Optimum Process ◽  
Great Cost ◽  
Frp Composites ◽  
Hybrid Laminates

The Fibre Reinforced Plastic (FRP) composites are extensively used for a wide variety of applications in automobile, aerospace, chemical, biomedical and civil engineering fields due to their excellent properties. Composite materials offer significant advantages in strength-to-weight ratio and corrosion resistance over metallic materials. Initially FRP composites were based mainly on thermoset polymers because of the ease of manufacturing. But, recently FRP composites using thermoplastics matrices are gaining importance because of their advantages over thermoset composites. In the present work, FRP laminates were fabricated using glass fabric and carbon fabric as reinforcements and thermoplastic polymer (polypropylene) as matrix. Fiber Reinforced Thermoplastics (FRTP) laminates of glass fibre /polypropylene (GF/PP), carbon fibre/ polypropylene (CF/PP) and glass-carbon fibre /polypropylene (GF/CF/PP) hybrid composite laminates were fabricated by film stacking method using hot compression molding press under optimum process parameters (pressure, temperature and dwell time). The fabricated FRTP laminates were tested for various mechanical and physical properties viz., tensile strength/modulus, flexural strength/modulus, izod impact strength, moisture absorption, barcol hardness and density as per relevant ASTM standards. The results of the tests carried out on three materials were compared. It was observed that hybrid laminate (GF/CF/PP) is superior in flexural strength/modulus as compared to GF/PP but the little lower mechanical properties compared to CF/PP laminates. But use of hybrid laminates has great cost advantage compared to CF/PP.

The Hygrothermal Degradation on Mechanical Properties of Short-Fiber Reinforced Nylon

2004 ◽  
Vol 261-263 ◽  
pp. 1427-1432 ◽  
Author(s):  
Dong Joo Lee ◽  
In Seop Lee
Keyword(s):  
Mechanical Properties ◽  
Sodium Chloride ◽  
Water Absorption ◽  
Moisture Absorption ◽  
Short Fiber ◽  
Fiber Reinforced ◽  
Fiber Volume ◽  
Diffusion Mechanisms ◽  
C 50 ◽  
Hygrothermal Degradation

The hygrothermal degradation of glass fiber/nylon composite was investigated after aged at 25°C, 50°C, 75°C and 100°C up to 1 month of total exposure in aqueous solution. The effects of moisture absorption and thermal aging on mechanical properties are compared as functions of temperature, fiber volume and concentration of sodium chloride. The amount of water absorption increases when the aging temperature is increased and the concentration of NaCl is lowered. In general, the mechanical properties decrease with amount of water absorption. The degradation rate of various mechanical properties is different depending on the temperature, fiber volume and the concentration of NaCl. The diffusion mechanisms of water in short-fiber reinforced nylon are discussed as functions of fiber volume, molding conditions and concentration of sodium chloride.

Effect of Moisture Absorption on the Bending Fatigue Performance of Carbon/Epoxy Laminates

2011 ◽  
Vol 415-417 ◽  
pp. 2308-2311
Author(s):  
A Ying Zhang ◽  
Di Hong Li ◽  
Cheng Li Liang ◽  
Jiu Si Jia ◽  
Dong Xing Zhang
Keyword(s):  
Moisture Content ◽  
Composite Laminates ◽  
Moisture Absorption ◽  
Threshold Level ◽  
Fatigue Tests ◽  
Experimental Results ◽  
Fatigue Properties ◽  
Material Strength ◽  
Bending Fatigue ◽  
Effect Of Moisture

This study investigates the effect of moisture content on the bending fatigue properties of T300/914 composite laminates immersed in water for 7 days and 14 days. Displacement-controlled three-point bending fatigue tests were conducted on specimens. After 40,000 cycles the fatigue test was stopped and the properties were measured on the tested specimens. Reduction in material strength was found to depend on the level of moisture content. Experimental results reveal that the moisture content in the laminates increased with immersion time and that moisture absorption accelerated damage propagation in the composite. Hygrothermal ageing lowered the threshold level for the onset of fatigue. The experimental results were further validated by the supportive micrographs that illustrate different moisture content and their morphology before and after moisture absorption.

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