scholarly journals Degassing and layers variation effect on composite processing by vacuum assisted resin transfer moulding

2021 ◽  
Vol 9 ◽  
Author(s):  
Alpa Tapan Bhatt ◽  
◽  
Piyush P Gohil ◽  
Vijaykumar Chaudhary ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Critical Issue ◽  
Thickness Variation ◽  
Void Content ◽  
Vacuum Degassing ◽  
Reinforced Composite ◽  
Before And After ◽  
Transfer Moulding ◽  
Vartm Process

Vacuum assisted resin transfer molding (VARTM) is a fiber reinforced composite (FRC) making process in which resin is impregnated to fabric by application of vacuum. This process is also known as vacuum infusion process. The critical issue in VARTM process is void generation. Voids form due to variety of reasons, most of which can be avoided. Vacuum degassing is one of the solutions which will reduce air entrapped inside resin during impregnation. In this work six laminates from jute and polyester resin were prepared, three with degassing and three without degassing with variation in number of jute layers 5, 10 and 15 respectively. Microscopic examination and mechanical properties have been observed before and after degassing. It was observed that degassing improves mechanical properties of composite laminates and reduce void content. It was observed that the thickness variation in laminate increased as number of layer increased.

VARTM Process Improvement for Repeatable and Improved Mechanical Properties of Composite Laminates

2009 ◽  
Author(s):  
Sanjay Sharma ◽  
Dennis A. Siginer
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Composite Laminates ◽  
Volume Fraction ◽  
Void Content ◽  
Molding Process ◽  
Fiber Volume ◽  
The Impact ◽  
Vartm Process

Quality of laminates produced by Seeman Composite Resin Infusion Molding Process (SCRIMP) is studied by comparing their Fiber Volume fraction and void content. SCRIMP is a variant of Vacuum Assisted Resin Transfer Molding (VARTM). Manufacturing process parameters are then identified and varied to study the impact on mechanical properties of laminated composites. Modification to SCRIMP is carried out by infusing the resin under additional pressure. Optimal process parameters for this modified SCRIMP process are suggested to yield laminates that are repeatable and consistent in quality. Void content is reduced in the composite laminates by altering the vacuum pressure level. Thickness gradient commonly found in SCRIMP processed laminates is eliminated by allowing longer de-bulking time. Final laminate quality is measured using ASTM standardized mechanical testing.

Mechanical Properties and Failure Analysis of Laminated Glass Reinforced Composite with Various Gelcoat Thickness

2016 ◽  
Vol 694 ◽  
pp. 8-12 ◽  
Author(s):  
M.Y. Yuhazri ◽  
G.C.H. Nilson ◽  
Haeryip Sihombing ◽  
Mohd Edeerozey Abd Manaf
Keyword(s):  
Mechanical Properties ◽  
Failure Analysis ◽  
Composite Laminates ◽  
Laminated Composite ◽  
Laminated Glass ◽  
Flexural Test ◽  
Reinforced Composite ◽  
Glass Fiber Reinforced ◽  
Flexural Tests ◽  
Different Thickness

The aim of this study is to evaluate the mechanical properties and study the failure of laminated glass reinforced composite coated with gelcoat of different thickness. Firstly, the gelcoat was applied to the mould using brush and subsequently, glass fiber reinforced composite laminates were fabricated on it using vacuum bagging technique. The mechanical properties of the composites various were tested by using tensile and three-point flexural tests. The fracture behaviour of different gelcoat thickness was observed using scanning electron microscope (SEM) to determine the failure behaviour that occurred. The flexural test was performed in two ways, i.e., gelcoat layer facing top and facing down. For both flexural tests, composite coated with 0.30 mm thick of gelcoat shows the highest mechanical strength. Tensile test is useful to investigate the interfacial bonding in between gelcoat and laminate composite. The composite coated with 0.40 mm of gelcoat showed the highest tensile strength, an increase of 38 % compared to the uncoated composite. It was observed that an increase in gelcoat thickness increased the brittleness of the laminated composite. From the failure analysis, failures were caused by the delamination of matrix between the plies, while the gelcoat was still strongly bonded with composite laminate.

Novel sandwich structure of composite-metal laminates based on cellulosic woven pineapple leaf fibre

2020 ◽  
pp. 109963622093147
Author(s):  
Ng Lin Feng ◽  
Sivakumar Dhar Malingam ◽  
Noordiana Mohd Ishak ◽  
Kathiravan Subramaniam
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Synthetic Fibre ◽  
Research Work ◽  
Compression Moulding ◽  
Reinforced Composite ◽  
Environmental Friendly ◽  
Structural Applications ◽  
Fibre Metal ◽  
Sandwich Materials

Fibre metal laminates (FMLs) are the contemporary sandwich materials that have been employed in the aerospace industries. The commercially available synthetic fibre based FMLs have shown excellent fatigue, impact and specific properties over those of metallic alloys. In order to explore the potential of environmental friendly cellulosic based materials, this research work aims to characterise the mechanical properties of novel woven pineapple leaf fibre reinforced metal laminates which were prepared through the hot compression moulding technique. For the comparison purpose, the mechanical properties of woven pineapple leaf fabrics and pineapple leaf fibre reinforced composite laminates were determined as well. It was concluded that the pineapple leaf fibre reinforced metal laminates evidenced salient mechanical and specific properties over pineapple leaf fabrics and composites. The specific tensile strength of metal laminates was 230.87% and 62.21% higher than those of the pineapple leaf fabrics and composite laminates whereas the specific flexural strength of metal laminates was 174.91% higher than composite laminates. Besides that, metal laminates also showed an impact strength of 91.49 kJ/m2 which was 143.13% greater than that of the composite laminates. The results indeed showed that the pineapple based FMLs could be considered as the promising and sustainable sandwich materials in future structural applications.

Infra-Red Thermography based Inspection of Hybrid Composite Laminates under Flexure Loading

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
R. Bhoominathan ◽  
P. Divyabarathi ◽  
R. Manimegalai ◽  
T. Nithya ◽  
S. Shanmugapriya
Keyword(s):  
Composite Laminates ◽  
Volume Fraction ◽  
Void Content ◽  
Destructive Testing ◽  
Flexural Loading ◽  
Infra Red ◽  
Before And After ◽  
Cfrp Composite ◽  
Structural Parts ◽  
Non Destructive

Generally, the aircraft structural parts are economically high in cost so the materials need to be inspected for defects or damages using various non-destructive testing (NDT) methods like ultrasonic, thermography and acoustic emission. The aim of this project is to characterize the defects in composite laminates before and after the flexural loading using infra-red thermography NDT method. GFRP and hybrid (GFRP+CFRP) composite laminates are fabricated with different orientation such as uni-directional, cross ply, anti-symmetric and angle ply and then tested under flexural loading according to ASTM D790 standard. The volume fraction of the fibre and matrix needs to be found out to know the void content and the mixing ratio of reinforcement and binder.

Cure kinetics and autoclave-pressure dependence on physical and mechanical properties of woven carbon/epoxy 8552S/AS4 composite laminates

2021 ◽  
pp. 096739112110284
Author(s):  
Abd Baghad ◽  
Khalil El Mabrouk ◽  
Sébastien Vaudreuil ◽  
Khalid Nouneh
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Treatment Time ◽  
Physical And Mechanical Properties ◽  
Cure Kinetics ◽  
Void Content ◽  
Scanning Calorimetry ◽  
Microstructure And Mechanical Properties ◽  
The Matrix ◽  
Interlaminar Shear

The final mechanical properties of composite laminates are highly dependent on their curing cycles in the autoclave. During this cycle, the temperature, pressure, vacuum, and treatment time will influence the quality of manufactured parts. The void content is considered the most harmful defects in carbon/epoxy laminates since they weaken the matrix-dominated mechanical properties such as interlaminar shear and compressive strengths. In the present work, differential scanning calorimetry is used to characterize the influence of time/temperature on the behavior of the epoxy resin. Then, a series of [0/90/−45/+45]s laminates composites are autoclave-cured under various applied pressures to evaluate their impact on microstructure and mechanical properties. The interlaminar shear modulus, interlaminar shear strength, laminate compressive modulus, and laminate compressive strength at room and operating engine temperature were measured. The correlation between microstructure and mechanical properties was also studied. The mechanical properties of manufactured carbon/epoxy laminates are found to be dependent on pressure and microstructure. These results are explored to establish an optimal autoclave pressure route that would minimize porosity without counterbalancing mechanical properties.

scholarly journals Effects of the Vacuum Moulding Process on the Mechanical Properties of Cotton/Epoxy Composite

2018 ◽  
Vol 26 (3(129)) ◽  
pp. 93-97 ◽  
Author(s):  
Cristian Lozano Tafur ◽  
Edgar Espejo Mora ◽  
Rodolfo Rodríguez Baracaldo
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Epoxy Composite ◽  
Resin Transfer Moulding ◽  
Moulding Process ◽  
Vacuum Moulding ◽  
Untreated Material ◽  
Reinforcing Material ◽  
Transfer Moulding ◽  
Vartm Process

A study on the effect of the vacuum assisted resin transfer moulding (VARTM) manufacturing process on the mechanical properties of cotton/epoxy composite is presented in this investigation. Woven cotton was used as reinforcing material embedded in epoxy resin. The woven cotton was treated with sodium hydroxide for one hour at concentrations of 0% to 20%. The tensile test showed that the untreated material had the highest ultimate strength and Young’s modulus. Observation of the fracture surface by scan electronic microscopy (SEM) was compared to the hand lay-up process as well as the results of the tensile test. The comparison showed that the VARTM process presents better mechanical properties than the hand lay-up process due to the reduction in discontinuities observed by means of optical microscopy.

The Effects of Ultrasonic Treatment on Fiber-Reinforced Composite Materials

2009 ◽  
Author(s):  
Chad Braver ◽  
Matthew Tumey ◽  
Adam Harlow ◽  
Qingyou Han
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Ultrasonic Treatment ◽  
Void Content ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Three Point Bending ◽  
Reinforced Composite ◽  
The Matrix ◽  
Reinforcement Fiber

The mechanical properties of fiber-reinforced composite materials are highly dependent on proper saturation of the resin within the reinforcement fibers. The research evaluates the effect of ultrasonic treatment during composite curing, in an effort to increase interlaminar bonding strength, lower void content, and improve the matrices ability to transfer stresses to the reinforcement fiber. The testing methods that were performed evaluated the effects or the ultrasonic treatment on the specimen in three point bending, and shear between layers of the matrix. The mechanical properties and the microstructure of the test specimen are discussed.

Effects of cure cycles on void content and mechanical properties of composite laminates

2006 ◽  
Vol 73 (3) ◽  
pp. 303-309 ◽  
Author(s):  
Ling Liu ◽  
Bo-Ming Zhang ◽  
Dian-Fu Wang ◽  
Zhan-Jun Wu
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Void Content
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