Impact Damage Resistance of Glass/Epoxy Laminates with Embedded Shape Memory Alloy

2007 ◽  
Vol 345-346 ◽  
pp. 1529-1532 ◽  
Author(s):  
Ki Weon Kang ◽  
H.J. Kim ◽  
J.H. Kim ◽  
Heung Seob Kim ◽  
Yong Su Kim ◽  
...  

This paper deals with the damage resistance of glass/epoxy laminates with embedded shape memory alloy (SMA) subjected to low-velocity impact at various temperatures. For this goal, the impact tests were performed by using an instrumented impact-testing machine at three temperatures: +20°C, -10°C and -40°C. And the resultant damages were inspected through the scanning acoustic microscope (SAM). Also, based on the impact force history and the damage configuration, the impact resistance parameters were employed to evaluate damage resistance of laminates with embedded SMA wires. As results, it was found that the damage resistance of glass/epoxy laminates with embedded SMA wires is dependent on the service temperature.

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2657-2663 ◽  
Author(s):  
KI-WEON KANG ◽  
HEUNG-SEOB KIM ◽  
TAE-JIN CHUNG ◽  
SEUNG-KEE KOH

This paper aims to evaluate the effect of temperature on impact damage resistance of glass/epoxy laminates. A series of impact tests were performed using an instrumented impact-testing machine at temperature ranging from -40°C to +80°C. The resulting impact damage was measured using back light method. The impact resistance parameters were employed to understand the damage resistance. It was observed that temperature has a little effect on the impact responses of composite laminates. The damage resistance of glass/epoxy laminates is somewhat deteriorated at two opposite extremes of the studied temperature range and this behavior is likely due to the property change of glass/epoxy laminates under extreme temperatures


2006 ◽  
Vol 326-328 ◽  
pp. 1793-1796
Author(s):  
Ki Weon Kang ◽  
Seung Yong Yang ◽  
J.H. Kim ◽  
Jung Kyu Kim ◽  
Heung Seob Kim ◽  
...  

This paper deals with the damage behavior of glass/epoxy composite laminates subjected to low-velocity impact at various temperatures. For this goal, the impact tests were performed by using an instrumented impact-testing machine at three temperatures: +20°C, -10°C and -40°C. And the resultant damages were inspected through the scanning acoustic microscope (SAM). Also, based on the impact force history and the damage configuration of the laminates, the impact resistance parameters were employed to evaluate damage resistance of glass/epoxy laminates. As results, it was found that the temperature changes affect the damage resistance capacity of glass/epoxy laminates.


2006 ◽  
Vol 306-308 ◽  
pp. 279-284
Author(s):  
Ki Weon Kang ◽  
Jung Kyu Kim ◽  
Heung Seob Kim

The goals of the paper are to identify the impact damage and strength reduction behavior of sandwich structure, composed of carbon/epoxy laminates skin and Nomex core with two kinds of thickness (10 and 20mm). For these, low velocity impact tests were conducted using the instrumented impact-testing machine and damages are inspected by SAM. And then, subsequent static tests are conducted under flexural loading to identify the strength reduction behavior of the impacted sandwich structures. The impact damages are mainly delamination in carbon/epoxy skin and their behavior is mostly independent of core thickness. Also, their energy absorbing behavior is identified through calculating the energy absorbed by impact damage. Finally, the strength reduction behavior is evaluated through Caprino’s model, which was proposed on the unidirectional laminates.


Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1026 ◽  
Author(s):  
Hao Li ◽  
Jingbiao Liu ◽  
Zhenqing Wang ◽  
Zhengwei Yu ◽  
Yanfei Liu ◽  
...  

Polymer composites are sensitive to impact loading due to their low impact resistance. Shape memory alloy (SMA) wires have been used to improve the impact resistance of the polymer composite materials because of their unique superelasticity performance. In this study, a new SMA hybrid basalt fiber-reinforced polymer composite embedded with two perpendicular layers of superelastic SMA wires is designed and the low-velocity impact behavior is experimental investigated. For contrast, the conventional polymer composite without SMA wires is also tested as the reference laminate. The tests are carried out at three different impact energy levels (30, 60 and 90 J). Moreover, to find out indications for manufacturing of SMA hybrid composites with high impact resistance, four different SMA wires embedded modes are investigated. Visual inspection and scanning electron microscope methods are adopted to identify the damage modes of the impacted samples. Results show that the impact resistance of the hybrid laminates is improved due to the hybridization of SMA wires. The most effective impact resistance of the SMA hybrid composites can be obtained by incorporating the SMA wires with one layer between the front two plies and another layer between the bottom two plies into the composite structure.


2012 ◽  
Vol 445 ◽  
pp. 959-964
Author(s):  
Z. Khan ◽  
Necar Merah ◽  
A. Bazoune ◽  
S. Furquan

Low velocity drop weight impact testing of CPVC pipes was conducted on 160 mm long pipe sections obtained from 4-inch (100 mm) diameter schedule 80 pipes. Impact test were carried out for the base (as received) pipes and after their exposure to out door natural weathering conditions in Dhahran, Saudi Arabia. The results of the impact testing on the natural (outdoor exposure) broadly suggest that the natural outdoor exposures produce no change in the impact resistance of CPVC pipe material for the impact events carrying low incident energies of 10 and 20J. At the impact energies of 35 and 50J the natural outdoor exposures appear to cause appreciable degradation in the impact resistance of the CPVC pipe material. This degradation is noted only for the longer exposure periods of 12 and 18 months.


2019 ◽  
Vol 26 (1) ◽  
pp. 517-530 ◽  
Author(s):  
Ye Wu ◽  
Yun Wan

AbstractDue to the properties of shape memory effect and super-elasticity, shape memory alloy (SMA) is added into glass fiber reinforced polymer (GFRP) face-sheets of foam core sandwich panels to improve the impact resistence performance by many researchers. This paper tries to discuss the failure mechanism of sandwich panels with GF/ epoxy face-sheets embedded with SMA wires and conventional 304 SS wire nets under low-velocity impact and compression after impact (CAI) tests. The histories of contact force, absorbed energy and deflection during the impact process are obtained by experiment. Besides, the failure modes of sandwich panels with different ply modes are compared by visual inspection and scanning electron microscopy (SEM). CAI tests are conducted with the help of digital image correlation (DIC) technology. Based on the results, the sandwich panels embedded with SMA wires can absorb more impact energy, and show relatively excellent CAI performance. This is because the SMA wires can absorb and transmit the energy to the outer region of GFRP face-sheet due to the super-elasticity-behavior. The failure process and mechanism of the CAI test is also discussed.


2019 ◽  
Vol 809 ◽  
pp. 9-14
Author(s):  
Florian Schimmer ◽  
Sven Ladewig ◽  
Nicole Motsch ◽  
Joachim M. Hausmann ◽  
Ingo Ehrlich

This paper investigates the damage behavior of thermoset and thermoplastic fiber-reinforced composites. The specimens were subjected to low-velocity impacts (LVI) to produce barely visible impact damages (BVID). To compare the dependency of the matrix system and the laminate lay-up on the impact damage, four test series were set up. Therefore, laminates with an epoxy (EP) and a polyether ether ketone (PEEK) matrix in a quasi-isotropic (QI) [+45/0/-45/90]2s and an orthotropic (OT) fiber lay-up [0/90]4s were manufactured. To eliminate the influence of variant fiber systems, the thermoplastic tape and the thermoset prepreg contain similar carbon fibers (CF). After impact testing with three different impact energies, inner damages were investigated by using ultrasonic analyses. To get a deeper understanding of the interior damage mechanisms, cross sections of the damaged areas were examined via reflected light microscopy. By using these destructive and non-destructive test methods, significant differences in the damage behavior of composites with thermoplastic and thermoset matrix systems were identified for both laminate lay-ups.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
J. T. Ruan ◽  
F. Aymerich ◽  
J. W. Tong ◽  
Z. Y. Wang

The delamination buckling and growth behaviors of a cross-ply composite laminate with damage induced by low velocity impact are investigated optically using three-dimensional digital image correlation (3D-DIC) method. For the 3D deformation measurement, the 3D-DIC setup comprised of two CCD cameras was adopted. The rectangle specimen was impacted under the impact energy of 7.0 J using a drop-weight testing machine, and the impact damage was detected by means of X-ray nondestructive evaluation (NDE) technique. The 3D deformation field measured with the optical system clearly reveals that the delamination buckling characteristic of the specimen mainly appears local deformation mode under compression after impact test. Moreover, the behavior of delamination growth evaluated by the 3D-DIC optical method reasonably agrees with the NDE observed damage result after compression.


2011 ◽  
Vol 117-119 ◽  
pp. 954-957
Author(s):  
Li Yan ◽  
Xue Feng An ◽  
Chen Qian Zhang ◽  
Xiao Su Yi

Damage behavior of composite stiffened plates of structure I and structure II at different positions and under different impact energy subjected to low-velocity impact testing was studied in this paper. Visual observation and ultrasonic C-scanning were also employed to inspect the damage size. The results showed that damage behavior of composite stiffened plates was not only related to damage behavior of laminates, but also related to damage between stringer and laminate and damage of stringer itself. It was found that the mechanism of absorbing energy varies with the impact position, as well as the damage behavior. When the impact position was near stringer, partial energy was absorbed by stringer to make stringer and laminate disengage and damage area of laminates was smaller. Damage behavior of composite stiffened plates varies with the structure. Damage area of samples of structure II was smaller than that of samples of structure I. It was estimated preliminarily that design of structure II was better than that of structure I.


2016 ◽  
Vol 23 (6) ◽  
pp. 699-710 ◽  
Author(s):  
Yucheng Zhong ◽  
Sunil Chandrakant Joshi

AbstractThe effects of hygrothermal conditioning and moisture on the impact resistance of carbon fiber/epoxy composite laminates were investigated. Specimens were fabricated from carbon fiber/epoxy woven prepreg materials. The fabricated specimens were either immersed in water at 80°C or subjected to hot/wet (at 80°C in water for 12 h) to cold/dry (at -30°C in a freezer for 12 h) cyclic hygrothermal conditions, which resulted in different moisture contents inside the laminates. It was found that the absorbed moisture did not migrate out from composite materials at -30°C. Neither of the hygrothermal conditions in this study had detrimental effects on the microstructure of the laminates. Low-velocity impact testing was subsequently conducted on the conditioned specimens. When attacked by the same level of impact energy, laminates with different moisture levels experienced different levels of impact damage. Moisture significantly alleviated the extent of damage in carbon fiber/epoxy woven laminates. The elastic response of the laminate under impact was improved after hygrothermal conditioning. The mechanism behind the improved impact resistance after absorbing moisture was proposed and deliberated.


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