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.

Damage Characterization of Carbon and Glass Fiber Composite Plates Subjected to Low-Velocity Impact Using Thermography

2018 ◽  
Author(s):  
Khaled S. Al-Athel ◽  
Ahmed Alomari ◽  
Abul Fazal M. Arif
Keyword(s):  
Glass Fiber ◽  
Composite Laminates ◽  
Impact Damage ◽  
Fiber Composite ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Damage Characterization ◽  
Post Impact

Composites are prone to delamination damage when impacted by low velocity projectiles because of the poor through-thickness strength. Therefore, some of the problems with composites are their poor impact damage resistance, weak post-impact mechanical properties, and the difficulty to inspect the impacted area by nondestructive means. Damage characterization of composite materials requires a scientific methodology, knowledge of polymeric materials, and direct field experience. In this work, low-velocity impact response of composite laminates was experimentally studied using drop-tower to determine the energy absorption. Three types of composites were used: carbon fiber, glass fiber, and mixed fiber composite laminates. In addition, these composites were characterized using thermography to quantify their post impact damage. It was found with the 3D temperature distribution that a strong correlation can be determined between the measured temperatures at the impact region with the quantification of the damage using thermal imaging with advanced mid-wave camera.

scholarly journals Isogeometric analysis for simulation of progressive damage in composite laminates

2018 ◽  
Vol 52 (25) ◽  
pp. 3471-3489 ◽  
Author(s):  
Marco S. Pigazzini ◽  
Yuri Bazilevs ◽  
Andrew Ellison ◽  
Hyonny Kim
Keyword(s):  
Composite Laminates ◽  
Isogeometric Analysis ◽  
Composite Structures ◽  
Low Velocity Impact ◽  
Stiffened Panel ◽  
Progressive Damage ◽  
Low Velocity ◽  
New Class ◽  
Aerospace Applications ◽  
Post Impact

The increasing popularity of composite materials in aerospace applications is creating the need for a new class of predictive methods and tools for the simulation of progressive damage in laminated fiber-reinforced composite structures. The unique challenges associated with modeling damage in these structures may be addressed by means of thin-shell formulations which are naturally developed in the context of Isogeometric Analysis. In this paper, we further validate our recently developed Isogeometric Analysis-based multi-layer shell model for progressive damage simulations using experimental data for low-velocity impact on a 24-ply flat panel. The validation includes a careful comparison of delamination and matrix damage patterns predicted by the Isogeometric Analysis-based simulation and those obtained from post-impact non-destructive evaluation of the damaged coupon. The Isogeometric Analysis-based formulation is then deployed on two additional examples: a stiffened panel and a full-scale UAV wing, to demonstrate its suitability for, and ease of application to, typical aerospace composite structures.

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.

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

Delamination Threshold Load of Composite Laminates under Low-Velocity Impact

2012 ◽  
Vol 525-526 ◽  
pp. 521-524
Author(s):  
Y.G. Xu ◽  
Z. Shen ◽  
W. Tiu ◽  
Y.Z. Xu ◽  
Yong K. Chen ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Composite Laminates ◽  
Impact Damage ◽  
Energy Levels ◽  
Low Velocity Impact ◽  
Thickness Effect ◽  
Low Velocity ◽  
Velocity Impact ◽  
Key Factor ◽  
Laminate Thickness

A key factor affecting the use of carbon fibre reinforced composite laminates is the low velocity impact damage which may be introduced accidentally during manufacture, operation or maintenance of the component. Among the several barely visible impact damages, interlaminar delamination is the dominant failure mode and may reduce the post-impact compressive strength of the component significantly. This paper focuses on the study of the delamination threshold load (DTL) above which significant increase of delamination and thus large reduction of the residual compressive strength of the component may occur. Instrumented drop weight tests were carried out under various impact energy levels to determine the delamination threshold load. Efforts are directed to the study of the laminate thickness effect on the reliability of the detection of the DTL. The validity of the concept of DTL has been investigated and possible implications on the measurement of the DTL has been discussed. It is demonstrated that DTL exists but its detection requires proper testing conditions.

Impact Damage Research of Sandwich Composite Laminates

2013 ◽  
Vol 710 ◽  
pp. 136-141
Author(s):  
Li Jun Wei ◽  
Fang Lue Huang ◽  
Hong Peng Li
Keyword(s):  
Compressive Strength ◽  
Composite Laminates ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Sandwich Composite ◽  
Low Velocity ◽  
Compression Process ◽  
Velocity Impact ◽  
Residual Compressive Strength ◽  
Core Materials

Sandwich composite laminates structure is a classic application of composite material on actual aircraft structural. Dealing with low-velocity impact damage and residual compressive strength of sandwich composite laminates, explicit finite element method of ABAQUS/Explicit software was adopted to simulate low-velocity impact and compression process. Impact response and invalidation on compression between sandwich composite laminates with different core materials and regular composite laminates were compared. The simulation results indicated that softer core materials can absorb more impact energy, reduce the structure damage and enhance the residual compressive strength after impact.

Experimental investigation on a fully thermoplastic composite subjected to repeated impacts

2019 ◽  
Vol 233 (19-20) ◽  
pp. 6985-7002
Author(s):  
S Boria ◽  
A Scattina ◽  
G Belingardi
Keyword(s):  
Composite Laminates ◽  
Mechanical Performance ◽  
Impact Damage ◽  
Energy Levels ◽  
Thermoplastic Composite ◽  
Thermoplastic Composites ◽  
Low Velocity ◽  
Repeated Impacts ◽  
Structural Parts ◽  
The Impact

In the last years, the spread of composite laminates into the engineering sectors was observed; the main reason lies in higher values of strength/weight and stiffness/weight ratios with respect to conventional materials. Firstly, the attention was focused on fibres reinforced with thermosetting matrix. Then, the necessity to move towards low density and recyclable solutions has implied the development of composites made with thermoplastic matrix. Even if the first application of thermoplastic composites can be found into no structural parts, the replacement of metallic structural parts with such material in areas potentially subjected to impact has become worthy of investigation. Depending on the field of application and on the design geometry, in fact, some components can be subjected to repeated impacts at localized sites either during fabrication, activities of routine maintenance or during service conditions. When composite material was adopted, even though the impact damage associated to the single impact event can be slight, the accumulation of the damage over time may seriously weaken the mechanical performance of the structure. In this overview, the capability of energy absorption of a new composite completely made of thermoplastic material was investigated. This material was able to combine two conflicting requirements: the recyclability and the lightweight. In particular, repeated impacts at low velocity, on self-reinforced laminates made of polypropylene (PP), were conducted by experimental drop dart tests. Repeated impacts up to the perforation or up to 40 times were performed. In the analysis, three different energy levels and three different values of the laminate thicknesses were considered in order to analyse the damage behaviour under various experimental configurations. A visual observation of the impacted specimens was done, in order to evaluate the damage progression. Moreover, the trend of the peak force interchanged between specimen and dart and the evolution of both the absorbed energy and of the bending stiffness with the impacts number were studied. The results pointed out that the maximum load and the stiffness of the specimens tended to grow increasing the number of the repeated impacts. Such trend is opposite compared to the previous results obtained by other researchers using thermosetting composites.

Comparison of the impact damage resistance of non-hybrid and intra-ply hybrid carbon/E-glass/polypropylene non-crimp thermoplastic composites

2018 ◽  
Vol 38 (1) ◽  
pp. 31-45 ◽  
Author(s):  
Gaye Kaya
Keyword(s):  
Damage Tolerance ◽  
Impact Damage ◽  
Low Velocity Impact ◽  
Thermoplastic Composites ◽  
Low Velocity ◽  
Impact Properties ◽  
Compression After Impact ◽  
Post Impact ◽  
The Impact ◽  
Hybrid Carbon

This study aims to compare the low-velocity impact and post-impact properties of intra-ply hybrid carbon/E-glass/polypropylene non-crimp thermoplastic composites with non-hybrid carbon/PP and E-glass/PP non-crimp thermoplastic composites. Impact test was performed at four energy levels as 15 J, 30 J, 45 J and 60 J. Post-impact properties of hybrid thermoplastic composites were tested by compression after impact method for each energy level to understand the impact damage tolerance of intra-ply hybrid carbon/E-glass/PP non-crimp thermoplastic composites. The effect of hybridization on energy absorption of composites was not significant, while C-scan results showed that the intra-ply hybrid non-crimp thermoplastic composites had smaller impact damage areas in comparison to the non-hybrid samples. Compression and compression after impact tests results confirmed that the intra-ply hybridization increased the toughness of the composite laminates. Also, the residual compression strength/modulus increased with hybridization which indicated to damage tolerance.

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