scholarly journals EFFECT OF THE STACKING SEQUENCE ON THE IMPACT RESPONSE OF CARBON-GLASS/EPOXY HYBRID COMPOSITES

2020 ◽  
Vol 18 (1) ◽  
pp. 069
Author(s):  
Hafiz Tauqeer Ali ◽  
Roya Akrami ◽  
Sakineh Fotouhi ◽  
Farzad Pashmforoush ◽  
Cristiano Fragassa ◽  
...  

This paper investigates low-velocity impact response of Quasi Isotropic (QI) hybrid carbon/glass fiber reinforced polymer composites with alternate stacking sequences. Cross-ply woven carbon and glass fibers were used as reinforcing materials to fabricate sandwiched and interlayer hybrid composites. For comparison, the laminates containing only-carbon and only-glass fibers were also studied. Drop weight test was used to impact the samples. The images captured by a normal camera demonstrated that localized damages (delamination) existed within plies. The hybrid laminates had smaller load drops, smaller maximum deflection, and higher maximum load compared to the single fiber laminates. In addition, carbon outside interlayer hybrid laminate showed the highest maximum load and energy absorption, showing the significant dependence of the impact performance on hybridization and stacking sequence. It was concluded that a hybrid composite would help improve impact performance of laminated composites compared to non-hybrid composites if they are properly designed.

2017 ◽  
Vol 54 (2) ◽  
pp. 286-290 ◽  
Author(s):  
Marina Bunea ◽  
Radu Bosoanca ◽  
Cristian Eni ◽  
Nicoleta Cristache ◽  
Victorita Stefanescu

In this research, the impact behavior of hybrid composite materials subjected to low-velocity impact using the drop-weight installation was investigated. For this study were manufactured eight hybrid materials. All the materials were tested to 90J impact energy. The effect of fabric types used in outer layers on impact performance was studied. The impact characteristics of hybrid materials with G1 glass fabric sheets were compared with those of hybrid materials with G2 glass fabric sheets. The damage surfaces of hybrid laminates were examined by visual investigation. The results obtained showed that the using of G2 glass fabric in structure of hybrid materials improved considerable the impact characteristics.


2000 ◽  
Author(s):  
M. Motuku ◽  
R. M. Rodgers ◽  
S. Jeelani ◽  
U. K. Vaidya

Abstract The effect of foam core density and facesheet thickness on the low velocity impact response and damage evolution in homogeneous foam core sandwich composites was studied. The failure characteristics, initiation and evolution of damage as well as the effect of impact energy were investigated. A Dynatup 8210 Impact Test Machine was utilized to conduct the low-velocity impact tests. Characterization of the impact response was performed by comparing the impact load histories, impact plots and failure characteristics. Fractography analysis was conducted through the use of scanning electron microscopy (SEM) and optical microscopy. Three types of foam cores with different densities, namely Airlite B12.5, Rohacell IG-71R63 and Airex R63.5 foam cores, were used to study the effect of core density. Considering four groups of facesheets made of different layers of cross-ply carbon prepregs performed the effect of facesheet thickness. For all the facesheet thicknesses (0.011-0.894-cm thick) and impact energy (11-40 J) range considered in this study, the maximum load (Pm), deflection-at-maximum load (δm) and time-to-maximum load (tm) exhibited strong influence or dependence on the type of foam core as opposed to the facesheet thickness. The energy-to-maximum load (Em), total energy absorbed (Et) and total energy-to-impact energy (Et/Eimp) ratio became less sensitive on the foam core density (or type) with increasing facesheet thickness. A transition point from foam core to facesheet controlled impact behavior as a function of impact energy level was observed. The impact parameters varied either linearly or parabolically with impact energy depending on the impact energy level, type of foam core and facesheet thickness. Excellent repeatability of impact data was generally obtained with increase in foam core density.


2021 ◽  
Vol 11 (16) ◽  
pp. 7436
Author(s):  
Marco P. Silva ◽  
Paulo Santos ◽  
João Parente ◽  
Sara Valvez ◽  
Paulo N. B. Reis

Composites are used in a wide range of engineering applications, as a result, exposure to hostile environments is rather common and its mechanical properties degradation is unavoidable. It is necessary to have a complete understanding of the impact of hostile environments on mechanical performance, namely critical solicitations as low velocity impacts. Therefore, this work intends to analyse the low velocity impact response of a carbon fibre/epoxy composite, and a similar architecture with an epoxy matrix filled with cork, after immersion into different solutions: diesel, H2SO4, HCl, NaOH, distilled water, seawater, and seawater at 60 °C. These solutions significantly affected the impact properties. In this context, the maximum load, maximum displacement, and restored energy behaviour were studied to understand the influence of exposure time. It was possible to conclude that such impact parameters were significantly affected by the solutions, where the exposure time proved to be determinant. The benefits of cork on the perforation threshold were investigated, and this parameter increased when the epoxy matrix was filled with cork. Finally, cork filled epoxy laminates also show less variation in maximum load and recovered energy than carbon/epoxy laminates.


2000 ◽  
Author(s):  
M. Motuku ◽  
U. K. Vaidya ◽  
G. M. Janowski ◽  
G. Basappa ◽  
S. Jeelani

Abstract The influence of test conditions on the low velocity impact (LVI) response and damage evolution in neat resin plaques was investigated and documented. Specifically, the effect of impactor mass, velocity, and corresponding impact energy on the LVI response and damage evolution in unreinforced DERAKANE vinyl ester 411-350-resin system was studied. An instrumented drop weigh test machine was used to conduct the low velocity impact tests. The room temperature response of the material to impact loading and damage evolution was investigated using the impact load histories, impact plots and fractography analysis. This study is built upon previous work by the authors on LVI of neat resin systems, particularly those that have emerged as a new class of resins in liquid molding process. The study was motivated by the need for data and understanding of the failure characteristics of the individual constituents of a composite material such as in modeling of damage propagation and failure criteria analysis. For constant impact velocity, the time-to-maximum load (tm), total impact duration (tt), and the energy-to-maximum load to total energy absorbed (Em/Et) ratio increased, and energy absorbed after peak load (Ep) decreased with the mass of the impactor. For constant impactor mass, the time-to-maximum load and total impact duration decreased, the Em/Et ratio remained fairly the same, and energy absorbed after peak load increased with velocity; i.e., the impact velocity and mass had opposing effects on the time-to-maximum load, the total impact duration, Em/Et and energy absorbed after peak load. A single layer of plain-weave S2-glass fabric was incorporated in some of the unreinforced plaques in order to analyze the influence of reinforcement on the impact response and damage evolution. Insertion of a fabric layer aided in containment of the damage within the bounds of the specimen and to isolate the failure characteristics, which enabled further analysis of the impact response and damage evolution.


2018 ◽  
Vol 53 (1) ◽  
pp. 3-17 ◽  
Author(s):  
J Jefferson Andrew ◽  
Sivakumar M Srinivasan ◽  
A Arockiarajan

This paper aims to investigate the effect of homogenous and hybrid external patches based on plain weave woven glass and Kevlar fabric on low velocity impact and quasi-static tensile after impact response of adhesively bonded external patch repairs in damaged glass/epoxy composite laminates. In all hybrid patches, the proportion of Kevlar and glass fibers were equal (i.e. 50% of Kevlar and 50% of glass by volume fraction), while lay-up configuration was different. This further enables to study the associated effect of hybridization and lay-up configuration on impact response of the repaired laminates. The intent of using hybrid external patches is to combine the excellent high displacement-to-failure property of Kevlar fiber as a ductile reinforcement with the superior mechanical property of glass fiber as a brittle reinforcement. The effect of glass/Kevlar content on impact response and tensile after impact response was investigated for various incident impact energy levels, such as 2, 4, 6, and 8 J. Results showed that hybridization and lay-up configurations of the external patches played a significant role on low velocity impact and quasi-static tensile after impact response of the repaired glass/epoxy specimens. Specimens repaired using intra-ply hybrid patches showed better impact properties and damage tolerance capability than that of the virgin and other repaired specimens. In specific, the use of intra-ply hybrid patches reduced the impact energy absorption by 10.17% in comparison to the virgin specimens at impact energy of 8 J.


2020 ◽  
Vol 54 (27) ◽  
pp. 4185-4205 ◽  
Author(s):  
MA Abd El-baky ◽  
MA Attia ◽  
MM Abdelhaleem ◽  
MA Hassan

An experimental study on tensile, flexural and impact properties of flax-basalt-glass reinforced epoxy hybrid composites is presented in this paper. Test specimens were fabricated by vacuum bagging process. The effects of reinforcement hybridization, fiber relative amounts and stacking sequence on the mechanical properties were investigated. Morphological studies of the fabricated and fractured surfaces through thickness were performed using scanning electron microscopy. Results showed that the developed hybrid composites display enhanced tensile, flexural and impact performance as compared with flax reinforced epoxy composite. The flexural strength increases when partial laminas from flax/epoxy laminate are replaced by basalt/epoxy and/or glass/epoxy laminas. Also, it is realized that incorporating high-strength fibers, i.e. glass or basalt, to the outer layers of the composite leads to higher flexural resistance, whilst the opposite was noticed for tensile properties. The fabricated hybrids were found to have economical and specific mechanical properties benefits. Fiber-relative amounts and stacking sequence have great effects on the mechanical properties. The mechanical properties of hybrid laminates are proven to be highly dependent on the position of the flax layers within the hybrid composite. The Hybridization with basalt and/or glass fibers is an effective method for enhancing the mechanical properties of flax/epoxy composites.


2016 ◽  
Vol 36 (6) ◽  
pp. 422-434 ◽  
Author(s):  
Sun Ying ◽  
Tang Mengyun ◽  
Rong Zhijun ◽  
Shi Baohui ◽  
Chen Li

In the current study, the low-velocity impact response of hybrid-laminated composites based on the twill woven fabrics was investigated experimentally. The following five different types of carbon–aramid/epoxy hybrid laminates were produced and tested, (a) two types of interply hybrid, (b) two types of sandwich-like interply hybrid, and (c) intraply hybrid. Non-hybrid carbon and aramid twill woven laminates were also tested for comparison. The effects of the hybrid structure on the impact properties such as the peak load, the ductility index, and damage area were discussed. The impact damage resistances of specimens were evaluated by comparing damage images taken from both the impacted and the non-impacted surface. The damage and failure mechanisms were analyzed from the impact damage morphologies using ultrasonic C-scan and three-coordinate measuring device. Under the same impact energies, the interply hybrid laminates with carbon fabric on the impact surface have higher impact damage resistance. It can be concluded that placing of high stiffness carbon fabric at highly stressed regions as reinforcement would result in enhanced properties, and the damage tolerance performance of composites with interply hybrid structure are better than those of other hybrid composites.


2021 ◽  
pp. 152808372110154
Author(s):  
Ziyu Zhao ◽  
Tianming Liu ◽  
Pibo Ma

In this paper, biaxial warp-knitted fabrics were produced with different high tenacity polyester linear density and inserted yarns density. The low-velocity impact property of flexible composites made of polyurethane as matrix and biaxial warp-knitted fabric as reinforcement has been investigated. The effect of impactor shape and initial impact energy on the impact response of flexible composite is tested. The results show that the initial impact energy have minor effect on the impact response of the biaxial warp-knitted flexible composites. The impact resistance of flexible composite specimen increases with the increase of high tenacity polyester linear density and inserted yarns density. The damage morphology of flexible composite materials is completely different under different impactor shapes. The findings have theoretical and practical significance for the applications of biaxial warp-knitted flexible composite.


2016 ◽  
Vol 87 (16) ◽  
pp. 1938-1952 ◽  
Author(s):  
Chao Zhi ◽  
Hairu Long ◽  
Fengxin Sun

The aim of this research was to investigate the low-velocity impact properties of syntactic foam reinforced by warp-knitted spacer fabric (SF-WKSF). In order to discuss the effect of warp-knitted spacer fabric (WKSF) and hollow glass microballoon parameters on the impact performance of composites, eight different kinds of SF-WKSF samples were fabricated, including different WKSF surface layer structures, different spacer yarn diameters and inclination-angles, different microballoon types and contents. The low-velocity impact tests were carried out on an INSTRON 9250 HV drop-weight impact tester and the impact resistances of SF-WKSF were analyzed; it is indicated that most SF-WKSF specimens show higher peak impact force and major damage energy compared to neat syntactic foam. The results also demonstrate that the surface layer structure, inclination-angle of the spacer yarn and the volume fraction and type of microballoon have a significant influence on the low-impact performance of SF-WKSF. In addition, a finite element analysis finished with ANSYS/LS-DYNA and LS-PrePost was used to simulate the impact behaviors of SF-WKSF. The results of the finite element analysis are in agreement with the experimental results.


Sign in / Sign up

Export Citation Format

Share Document