scholarly journals Microtomographic Analysis of Impact Damage in FRP Composite Laminates: A Comparative Study

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
M. Alemi-Ardakani ◽  
A. S. Milani ◽  
S. Yannacopoulos ◽  
L. Bichler ◽  
D. Trudel-Boucher ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Glass Fibers ◽  
Impact Testing ◽  
Frp Composites ◽  
Frp Composite ◽  
Flexural Testing ◽  
Close Relationship ◽  
High Level ◽  
Tomographic Analysis

With the advancement of testing tools, the ability to characterize mechanical properties of fiber reinforced polymer (FRP) composites under extreme loading scenarios has allowed designers to use these materials in high-level applications more confidently. Conventionally, impact characterization of composite materials is studied via nondestructive techniques such as ultrasonic C-scanning, infrared thermography, X-ray, and acoustography. None of these techniques, however, enable 3D microscale visualization of the damage at different layers of composite laminates. In this paper, a 3D microtomographic technique has been employed to visualize and compare impact damage modes in a set of thermoplastic laminates. The test samples were made of commingled polypropylene (PP) and glass fibers with two different architectures, including the plain woven and unidirectional. Impact testing using a drop-weight tower, followed by postimpact four-point flexural testing and nondestructive tomographic analysis demonstrated a close relationship between the type of fibre architecture and the induced impact damage mechanisms and their extensions.

Terahertz Ray Nondestructive Characterizations in FRP Composites

2010 ◽  
Vol 123-125 ◽  
pp. 839-842 ◽  
Author(s):  
Je Woong Park ◽  
Kwang Hee Im ◽  
David K. Hsu ◽  
Chien Ping Chiou ◽  
Daniel J. Barnard
Keyword(s):  
Composite Laminates ◽  
Electromagnetic Properties ◽  
Reflection Mode ◽  
Frp Composites ◽  
Frp Composite ◽  
Application Systems ◽  
Spectroscopy System ◽  
Terahertz Ray ◽  
Characterization Procedure ◽  
Good Agreement

Recently, terahertz ray imaging has emerged as one of the most promising new powerful nondestructive evaluation (NDE) techniques, and new application systems are under processing development for the area applications. In this study, a new time-domain spectroscopy system was utilized for detecting and evaluating layup effect and flaw in FRP composite laminates. Extensive experimental measurements in reflection mode were made to map out the T-ray images. Especially in this characterization procedure, we estimated the electromagnetic properties such as the refractive index. Estimates of properties are in good agreement with known data. Furthermore layup effect and flaw of FRP composite laminates were observed in reflection mode and limitations will be discussed in the T-ray processing.

scholarly journals The effect of temperature on fatigue strength and damage of FRP composite laminates

2021 ◽  
Author(s):  
Hossein Mivehchi
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Ultimate Tensile Strength ◽  
Fatigue Damage ◽  
Composite Laminates ◽  
Damage Model ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Frp Composites ◽  
Frp Composite

The present study intends to investigate the effect of temperature on cumulative fatigue damage of laminated fibre-reinforced polymer (FRP) composites. The effect of temperature on fatigue damage is formulated based on a previously proposed residual stiffness fatigue damage model. The fatigue strength of FRP composite laminates is also formulated to have temperature dependent parameters. The research work is divided into three main parts; the first part reviews the fatigue damage mechanism is fibre-reinforced composites based on stiffness degradation. The recent residual stiffness of Varvani-Shirazi was used as the backbone structure of damage analysis in this thesis. This model is capable of damage assessment while the effects of maximum stress, stress ratio and fibre orientation of FRP composites were recognized. The Varvani-Shirazi damage model was further developed to assess fatigue damage of FRP composites at various temperatures (T). Inputs of the damage model are temperature dependent parameters including Young's modulus (E), ultimate tensile strength(ðult) and fatigue life (Nf). As the next part of the proposed analysis, the temperature dependency of each parameter is formulated, and the relations of E-T and ðult-T are substituted in the Varvani-Shirazi fatigue model. Finally, all terms and equations are evaluated with the experimental data available in the literature. Six sets fatigue data were used in this thesis to evaluate fatigue of FRP specimens. The predicted results were found to be in good agreement with the experimentally obtained data. The proposed fatigue damage model was found promising to predict the fatigue damage of unidirectional (UD) and women FRP composites at different temperatures. Temperature dependant parameters of Young's modulus, ultimate tensile strength, and S-N diagram were also found to be responsive when used of UD, cross-ply, and quasi-isotropic FRP laminates.

Impact Damage Behavior of Glass/Epoxy Laminates for Railway Vehicle at Low Temperature

2006 ◽  
Vol 326-328 ◽  
pp. 1793-1796
Author(s):  
Ki Weon Kang ◽  
Seung Yong Yang ◽  
J.H. Kim ◽  
Jung Kyu Kim ◽  
Heung Seob Kim ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Testing Machine ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Railway Vehicle ◽  
Low Velocity ◽  
Damage Resistance ◽  
Damage Behavior ◽  
The Impact

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.

scholarly journals The effect of temperature on fatigue strength and damage of FRP composite laminates

2021 ◽  
Author(s):  
Hossein Mivehchi
Keyword(s):  
Tensile Strength ◽  
Fatigue Strength ◽  
Ultimate Tensile Strength ◽  
Fatigue Damage ◽  
Composite Laminates ◽  
Damage Model ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Frp Composites ◽  
Frp Composite

The present study intends to investigate the effect of temperature on cumulative fatigue damage of laminated fibre-reinforced polymer (FRP) composites. The effect of temperature on fatigue damage is formulated based on a previously proposed residual stiffness fatigue damage model. The fatigue strength of FRP composite laminates is also formulated to have temperature dependent parameters. The research work is divided into three main parts; the first part reviews the fatigue damage mechanism is fibre-reinforced composites based on stiffness degradation. The recent residual stiffness of Varvani-Shirazi was used as the backbone structure of damage analysis in this thesis. This model is capable of damage assessment while the effects of maximum stress, stress ratio and fibre orientation of FRP composites were recognized. The Varvani-Shirazi damage model was further developed to assess fatigue damage of FRP composites at various temperatures (T). Inputs of the damage model are temperature dependent parameters including Young's modulus (E), ultimate tensile strength(ðult) and fatigue life (Nf). As the next part of the proposed analysis, the temperature dependency of each parameter is formulated, and the relations of E-T and ðult-T are substituted in the Varvani-Shirazi fatigue model. Finally, all terms and equations are evaluated with the experimental data available in the literature. Six sets fatigue data were used in this thesis to evaluate fatigue of FRP specimens. The predicted results were found to be in good agreement with the experimentally obtained data. The proposed fatigue damage model was found promising to predict the fatigue damage of unidirectional (UD) and women FRP composites at different temperatures. Temperature dependant parameters of Young's modulus, ultimate tensile strength, and S-N diagram were also found to be responsive when used of UD, cross-ply, and quasi-isotropic FRP laminates.

TEMPERATURE EFFECT OF LOW VELOCITY IMPACT RESISTANCE OF GLASS/EPOXY LAMINATES

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2657-2663 ◽  
Author(s):  
KI-WEON KANG ◽  
HEUNG-SEOB KIM ◽  
TAE-JIN CHUNG ◽  
SEUNG-KEE KOH
Keyword(s):  
Composite Laminates ◽  
Impact Damage ◽  
Testing Machine ◽  
Impact Resistance ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Effect Of Temperature ◽  
Low Velocity ◽  
Damage Resistance ◽  
The Impact

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

scholarly journals Hybrid Bridge Structures Made of Frp Composite and Concrete

2017 ◽  
Vol 26 (3) ◽  
pp. 161-169
Author(s):  
Mateusz Rajchel ◽  
Tomasz Siwowski
Keyword(s):  
Failure Mode ◽  
Glass Fibers ◽  
Construction Materials ◽  
Bridge Engineering ◽  
Composite Failure ◽  
Frp Composites ◽  
Frp Composite ◽  
Hybrid Bridge ◽  
Bridge Structures ◽  
Contemporary Development

Abstract Despite many advantages over the conventional construction materials, the contemporary development of FRP composites in bridge engineering is limited due to high initial cost, low stiffness (in case of glass fibers) and sudden composite failure mode. In order to reduce the given limitations, mixed (hybrid) solutions connecting the FRP composites and conventional construction materials, including concrete, have been tested in many countries for 20 years. Shaping the hybrid structures based on the attributes of particular materials, aims to increase stiffness and reduce cost without losing the carrying capacity, lightness and easiness of bridges that includes such hybrid girders, and to avoid the sudden dangerous failure mode. In the following article, the authors described examples of hybrid road bridges made of FRP composite and concrete within the time of 20 years and presented the first Polish hybrid FRP-concrete road bridge. Also, the directions of further research, necessary to spread these innovative, advanced and sustainable bridge structures were indicated.

scholarly journals Impact response in polymer composites from embedded optical fibers

2018 ◽  
Vol 52 (25) ◽  
pp. 3415-3427 ◽  
Author(s):  
Lorianne K Batte ◽  
Rani W Sullivan ◽  
Vipul Ranatunga ◽  
Kevin Brown
Keyword(s):  
Optical Fibers ◽  
Composite Laminates ◽  
Composite Structures ◽  
Impact Damage ◽  
Energy Levels ◽  
Impact Testing ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Impact Surface ◽  
Post Impact

This study investigates the feasibility of using embedded optical fibers in polymer matrix composite laminates to characterize delaminations caused by low-velocity impacts with energies between 30 J and 50 J. Impact damage can occur in composite structures during manufacture, in-service, storage and routine maintenance. Because of their small size and light weight, optical fibers can be embedded in composite structures during the manufacture of composite parts, allowing the structure to be monitored for impact-induced delaminations without being removed from service. In this study, optical fibers are embedded in a grid configuration at four selected locations (one-third from impact surface, midplane, two-thirds from impact surface, and farthest ply from impact) in thick autoclave-cured graphite/epoxy laminates. Low-velocity impact testing is performed at four energy levels. Manufacturing procedures for embedding the optical fibers within the composite laminates are investigated. The strain distribution from the optical fibers is correlated with ultrasonic C-scans of the laminates in which they are embedded. X-ray computed tomography scan images are also compared to those from ultrasonic C-scans. Results indicate that embedded optical fibers can provide post-impact strain responses and delamination area from each embedded site within the impacted laminates.

Mechanical Properties of Structural Paper-Polypropylene Composite Laminates

2015 ◽  
Vol 825-826 ◽  
pp. 11-18 ◽  
Author(s):  
Martina Prambauer ◽  
Christian Paulik ◽  
Christoph Burgstaller
Keyword(s):  
Mechanical Properties ◽  
Composite Laminates ◽  
Natural Fiber ◽  
Glass Fibers ◽  
Cellulose Fiber ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Polypropylene Composites ◽  
Flexural Testing

Natural fiber reinforced polymers have gained increasing interest in research with the aim of replacing conventional reinforcements, such synthetic or glass fibers. In this work, whole paper sheets of copy, filter and newspaper were used for fabricating cellulose fiber reinforced polypropylene composites with MAPP as a coupling agent. By varying the amount and type of paper, the influence of these parameters on the mechanical properties was observed. The laminates were produced by a film hand stacking method and hot pressing. The characterization was carried out by tensile and flexural testing. Remarkable results were obtained for copy and newspaper composites at a fiber content of 30 and 40 vol.-%. In summary, structural paper reinforced composites with attractive mechanical properties were obtained, indicating the high potential of whole paper sheets as polymer reinforcement.

Development of Natural Fiber Reinforced Laminated Hybrid Composites

2012 ◽  
Vol 628 ◽  
pp. 15-20 ◽  
Author(s):  
Mustafa Bakkal ◽  
Mehmet Savas
Keyword(s):  
Glass Fiber ◽  
Composite Laminates ◽  
Natural Fiber ◽  
Hybrid Composites ◽  
Glass Fibers ◽  
Sem Analysis ◽  
Impact Testing ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
Positive Hybridization

In this study, mechanical properties of composite laminates reinforced with various forms of glass fibers have been investigated. Tensile testing, impact testing and optical microscopy and SEM analysis results were discussed. The results of glass fiber reinforced novel composite material have been compared with the results of a commercial car front bumper material tests performed in same conditions. Study concluds that glass fiber has positive hybridization effect and increased tensile strengths, elastic modules and impact strengths in laminar hybrid composites.

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