scholarly journals Effect of reinforcement material on impact properties of epoxy

2017 ◽  
Vol 2 (3) ◽  
pp. 226-231
Author(s):  
Basim M. Fadhil ◽  
Payman Sahbah Ahmed ◽  
Ava Ali Kamal

Impact characteristics of Epoxy matrix composites is investigated by impact machine. Four different types of reinforcement are used in the experimental works: type one: 1.9wt% steel fiber, 1.9wt% carbon fiber,1.9 wt% carbon nanotube, 1.9 wt% woven carbon fiber.This work shows that reinforcing epoxy with (1.9 wt% of woven carbon fiber) improves the impact properties where energy, force and deformation values of impact test for this composite were 18.4J, 3580.59 N and 18 mm respectively while for epoxy were 2.927 J, 921.849 N and 18.413 mm respectively.

Author(s):  
Mohamad Alsaadi ◽  
Bashar Younus ◽  
Ahmet Erklig ◽  
Mehmet Bulut ◽  
Omer Bozkurt ◽  
...  

The influence of various graphene nano-platelets (GNPs) content on the tensile, flexural and Charpy impact characteristics of carbon, Kevlar and hybrid carbon/Kevlar fibers reinforced epoxy matrix composites was investigated. Both of composite configurations as carbon and Kevlar at outer and core skins were experimentally tested. The SEM images for flexural specimens were taken to observe the adhesion mechanism of GnPs particles with fiber/epoxy system. It is found that hybridization with Kevlar layers is contributed a positive effect on the hybrid carbon/Kevlar laminate structures in terms of tensile, flexural and impact behaviour. The incorporation of GnPs particles in hybrid and non-hybrid composite samples results in significant improvements in tensile, flexural and impact properties, and the greatest improvement occurs within the GnPs particle content of 0.1 and 0.25 wt%, indicating that the interfacial bonding between the matrix and the fibers is better due to the large surface area of the GnPs and the good entanglement between the GnPs layers and the matrix chains. The samples of impact test are experimented for edgewise and flatwise directions.


Author(s):  
UA Khashaba ◽  
Ramzi Othman ◽  
Ismael MR Najjar

The present work aims to improve the mechanical properties of Epocast 50-A1/946 epoxy via incorporation of alumina nanoparticles using an ultrasonic agitation method. The optimum weight percentage of alumina nanoparticles was determined based on the improvement in the shear and impact properties of the nanocomposites at room temperature and 50 ℃. Accordingly, neat epoxy panels and nanocomposite panels with 0.5, 1.0, 1.5, and 2.0 wt% alumina nanoparticles were fabricated. The shear and thermo-mechanical impact properties of the panels were measured using an instrumented drop-weight impact machine and an Iosipescu shear test fixture, respectively, according to ASTMs D5379 and D7136. The maximum improvement in shear strength and modulus was 10.9% and 8.1%, respectively, for the nanocomposites containing 1.0 and 1.5 wt% alumina nanoparticles. The predicted shear moduli of the nanocomposites agreed well with the measured values with a maximum error of 6.52%. The optimal performance of impact properties was achieved by incorporating 1.0 wt% of alumina nanoparticles. Namely, the maximum impact-bending stiffness, contact force, and absorbed energy were increased by 12.9%, 13.0%, and 23.4%, respectively. The test temperature of 50 ℃ was found to have a negative effect on the impact-bending stiffness and the maximum contact force. On the other hand, the absorbed energy was increased up to 12.1%.


2018 ◽  
Vol 774 ◽  
pp. 410-415 ◽  
Author(s):  
Kazuto Tanaka ◽  
Ken Uzumasa ◽  
Tsutao Katayama

Carbon fiber reinforced thermoplastics (CFRTP) are expected to be used as a structural material for aircraft and automobiles not only for their mechanical properties such as high specific strength and high specific rigidity but also for their high recyclability and short molding time. Generally, in a composite material having a laminated structure, interlaminar delamination is often caused by an out-of-plane impact, so the interlayer property plays an important role in the mechanical properties. It has been reported that the fiber/matrix interfacial strength increases by grafting carbon nanotubes (CNT) on the carbon fiber surface. In this study, CNT grafted carbon fibers were used for reinforcement of CFRTP laminate for the improvement of impact properties of CFRTP laminates. The impact absorbed energy of the CFRTP laminate using CNT grafted carbon fibers as reinforcing fiber was higher than that using untreated CF.


2019 ◽  
Vol 974 ◽  
pp. 288-292
Author(s):  
Sergey A. Stelmakh ◽  
Anatoliy I. Shuyskiy ◽  
Evgeniy M. Shcherban ◽  
Albert Yu. Prokopov

The article considers and evaluates the impact of dispersed reinforcement of heavy concretes manufactured by means of vibration and centrifugation, various types of fibers on their strength-density ratio. The options of applying different types of heavy-weight aggregates for these concretes: crushed stone, limestone and sandstone are considered. The highest strength-density ratio is registered in centrifuged crushed stone fibrous concretes, and all types of centrifuged concretes has the ratio higher than vibrated concretes with the same composition of the studied fibers. The highest growth of the strength-density ratio for the centrifuged crushed stone fibrous concretes as compared with the vibrated ones was identified in case of dispersed reinforcement with steel fiber.


2014 ◽  
Vol 775-776 ◽  
pp. 296-301 ◽  
Author(s):  
Anderson de Paula Barbosa ◽  
Michel Picanço Oliveira ◽  
Giulio Rodrigues Altoé ◽  
Frederico Muylaert Margem ◽  
Sergio Neves Monteiro

The buriti (Muritia flexuosa) fiber are among the lignocellulosic fibers with apotential to be used as reinforcement of polymer composites. In recent years, the buriti fiber has been characterized for its properties as an engineering natural material. The toughness of buriti composites remains to be a evaluated. Therefore, the present work evaluated the toughness of epoxy composites reinforced with different amounts of buriti fibers by means of Charpy impact tests. It was found a significant increase in the impact resistance with the volume fraction of buriti fibers. Fracture observations by scanning electron microscopy revealed the mechanism responsible for this toughness behavior.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 203
Author(s):  
Sun-ho Go ◽  
Alexandre Tugirumubano ◽  
Hong-gun Kim

With the increasing use of carbon fiber reinforced plastics in various fields, carbon fiber composites based on prepregs have attracted attention in industries and academia research. However, prepreg manufacturing processes are costly, and the strength of structures varies depending on the orientation and defects (pores and delamination). For the non-contact evaluation of internal defects, the lock-in infrared thermography was proposed to investigate the defects in the composites subjected to the compression after impact test (CAI). The drop-weight impact test was conducted to study the impact behavior of the composites according to fibers orientation for composite fabricated using unidirectional (UD) carbon fiber prepregs. Using CAI tests, the residual compressive strengths were determined, and the damage modes were detected using a thermal camera. The results of the drop weight impact tests showed that the specimen laminated at 0° suffered the largest damage because of susceptibility of the resin to impact. The specimens with 0°/90° and +45°/−45° fibers orientation exhibited more than 90% of the impact energy absorption and good impact resistance. Furthermore, the specimens that underwent the impact tests were subjected to compressive test simultaneously with the lock-in thermography defects detection. The results showed that internal delamination, fibers splitting, and broken fibers occurred. The temperature differences in the residual compression tests were not significant.


2010 ◽  
Vol 143-144 ◽  
pp. 1022-1026 ◽  
Author(s):  
Xiao Ming Fan

The paper researched the electrical properties of carbon fiber graphite cement-matrix composites(CFGCC) containing carbon fiber 0.5% (mass fraction of cement, the same below) and graphite powder 0%~30%, and the impact of environmental temperature(10~50°C) and relative humidity (20%~60%) to electrical properties of CFGCC by the four-probe method and KSON high and low temperature environmental chambers. The results have shown: the electrical resistivity of CFGCC decreases with increasing the content of graphite; the relationship curve of electrical resistivity and concentration of graphite exists percolation phenomena, the percolation threshold of CFGCC is about 25%; the electrical resistivity of CFGCC have decreased with increasing temperature; the variation rate of electrical resistivity have decreased with increasing the contents of graphite; the electrical resistivity have changed a little as the humidity changed, and the trend is towards smaller as a whole.


2021 ◽  
pp. 002199832110587
Author(s):  
Sultan M Bayazeid ◽  
Kim-Leng Poon ◽  
Balakrishnan Subeshan ◽  
Mohammed Alamir ◽  
Eylem Asmatulu

Carbon fiber–reinforced composites (CFRCs) have been used extensively in structural applications within the aerospace and automotive manufacturing industries. However, several other applications have been recognized. These take advantage of the additional properties of CFRCs, which lead to providing better performance for structures. However, in their service environment, these CFRCs are inevitably susceptible to impact damage from multiple sources, and they must be able to recover from impacts to meet structural requirements. This study directs an experimental investigation of using induction heating (IH) for an impact-damaged CFRC. Here, IH process parameters, including the effects of electromagnetic frequency and generator power on the recovery of impact-damaged CFRC, have been analyzed. The anisotropic conductivity characteristics and the relationship between the drop-weight impact depth and conductivity of CFRC garnered much attention. This paper also offers the electromagnetic properties of CFRC for various applications. In this study, CFRC cured samples were obtained from Cetex® TC1200 PEEK, AS4 145 gsm, 16 unidirectional plies. Three variants of CFRC samples were tested: undamaged samples; samples with impact damage introduced in the center by a drop-weight impact test, according to the ASTM D7136/7136M standard; and samples with drop-weight impact damage recovered using the IH system. This work presents the results of the tensile strength of CFRC samples to assess the comparison of undamaged samples, samples damaged after the drop-weight impact test, and samples recovered after the drop-weight impact test. IH is appropriate for the recovery of impact-damaged CFRC samples, aiding in the conversion of electromagnetic energy to heat in order to generate mechanisms on components to recover the impact-damaged CFRC samples. Experimental results show that the impact-damaged area of the recovered CFRC samples is 37.0% less than that of damaged CFRC samples, and tensile strength results also improved after the impact-damaged CFRC samples were recovered. These results show that the IH method can effectively improve the impact damage performance of CFRC. The outcome of this study is promising for use in many applications, especially in the aerospace and automotive industries.


2010 ◽  
Vol 118-120 ◽  
pp. 226-230
Author(s):  
Xiang Zheng ◽  
Xiao Yan Tong ◽  
Hao Chen ◽  
Lei Jiang Yao

An experimental study of low-velocity impact characteristics and strength after impact was carried out on both woven fiber-reinforced resin matrix composites and woven fiber-reinforced ceramic matrix composites. The test specimens were impacted using a dropped-weight impact test apparatus with an instrumented spherical tip. Ultrasonic C-scan was used in nondestructive testing to characterize and quantify the impact damage. Much more damage of ceramic matrix composites than that of resin matrix composites occur and process in loading stage. The peak load of resin matrix composites is higher than that of ceramic matrix composites. According to the results of observing optical photographs and C-scan images, the damage area of ceramic matrix composites is greater than that of resin matrix composites and the difference increases as the energy increases. Damage resistance of ceramic matrix composites is lower than that of resin matrix composites, but damage tolerance of ceramic matrix composites is higher than that of resin matrix composites.


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