THE EFFECT OF MICROWAVE ELECTROMAGNETIC FIELD ON THE HARDNESS OF CARBON FIBER-REINFORCED PLASTIC WITH LIGHTNING PROTECTION GRID DISTRIBUTED IN THE SURFACE LAYER

2020 ◽  
Vol 0 (4) ◽  
pp. 5-11
Author(s):  
I.V. ZLOBINA ◽  
Keyword(s):  
Electromagnetic Field ◽  
Surface Layer ◽  
Carbon Fiber ◽  
Surface Hardness ◽  
Lightning Protection ◽  
Fiber Reinforced ◽  
Short Term Exposure ◽  
Structural Density ◽  
Carbon Fiber Reinforced ◽  
The Impact

Based on the analysis of scientific and technical literature and trends in the development of multi-purpose aircrafts, we can see a steady extension of the use of polymer composite materials (PCM) in their design. The importance of lightning protection is noted for aircrafts, the skin of which consists mainly of the PCM, and it is shown that one of the common means is a lightning protection coating (LPC) in the form of a metal grid distributed in the PCM surface layer. Anisotropy of PCM properties and reduced fracture toughness in comparison with metals necessitates the improvement of PCM compositions and technologies of their formation as well as the development of methods for final hardening treatment in the cured state, which can be effectively performed under the effect of microwave electromagnetic field. Consideration is given to the influence of a short-term exposure to microwave electromagnetic field on the stability of carbon fiber-reinforced PCM with PLC against impact loads, as well as on the surface hardness. Our findings show a decrease in the damaged area of the impact zone by 40-60% and the absence of microcracking and delamination as well as an increase in hardness by 7.8%. Particular emphasis is placed on a 3-fold decrease in the spread of hardness values after the microwave exposure, this indicating a significant increase in the uniformity of this important characteristic for the component performance. As a mechanism of these modifications, it is proposed to reduce the pore size and porosity and to increase the number of points of contact interaction between matrix and fiber agglomerates that ensure an increase in the structural density.

STUDYING THE EFFECT OF THE SCHEME OF EXPOSURE TO MICROWAVE ELECTROMAGNETIC FIELDS ON THE HARDNESS OF THE CURED CARBON FIBER-REINFORCED PLASTIC WITH LIGHTNING-PROTECTION GRID APPLIED ON ITS SURFACE

2020 ◽  
Vol 0 (4) ◽  
pp. 12-18
Author(s):  
I.V. ZLOBINA ◽  
Keyword(s):  
Electromagnetic Field ◽  
Carbon Fiber ◽  
Wind Turbines ◽  
Field Research ◽  
Carbon Plastic ◽  
Lightning Protection ◽  
Fiber Reinforced ◽  
Short Term ◽  
Short Term Exposure ◽  
Carbon Fiber Reinforced

Currently, the use of fiber-reinforced polymer composite materials (PCM), in particular, carbon plastic and fiberglass, is much promising in manufacturing structural elements of aircrafts and wind turbines. In order to increase the resistance of these materials to static electricity and lightning strikes when passing storm fronts, the structure of the PCM includes various lightning protection coatings (LPC). The most common LPC are in the form of copper grids. The fin assembly and planes of aircrafts and also large-sized blades of wind turbines are exposed to cyclic high-amplitude and low-frequency bending loads as well as vibrations. Collisions with solid objects are quite possible. Thus, hardness is one of the key characteristics of PCM that determines their performance properties. Strength and endurance of PCM components can be increased by short-term exposure to a microwave electromagnetic field. The presence of a built-in metallic structure brings additional uncertainty in the tolerance to operating loads by anisotropic PCM, as well as in the process of their interaction with an ultrahigh frequency electromagnetic field. Research was performed on the hardness of carbon fiber-reinforced plastics with built-in LPC using various exposure schemes to a microwave electromagnetic field: from the side of the LPC, from the side opposite to the LPC and sequential processing from both sides. It was found that short-term processing in a microwave electromagnetic field with energy flux density of (17-18)×104mW/cm2 did not lead to any change in the initial hardness of the surface of the samples. However, the uniformity of hardness distribution on the surface of the samples in- creased by 35.8-70%, thus ensuring a more adequate tolerance to loads of different nature. The obtained results can be used in the development of finishing technologies to post-process PCM components and improve the latter’s stability to dynamic loading.

scholarly journals Experimental analysis of composite scarf adhesive joints modified with multiwalled carbon nanotubes under bending and thermomechanical impact loads

2019 ◽  
Vol 234 (1) ◽  
pp. 48-64 ◽  
Author(s):  
UA Khashaba ◽  
Ramzi Othman ◽  
IMR Najjar
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Fiber ◽  
Multiwalled Carbon Nanotubes ◽  
Adhesive Joints ◽  
Impact Loads ◽  
Fiber Reinforced ◽  
Multiwalled Carbon ◽  
Impact Tests ◽  
Carbon Fiber Reinforced ◽  
The Impact

Scarf adhesive joints have attracted an increasing attention in joining/repairing of carbon fiber reinforced epoxy composite structures due to their zero eccentricity, which provides lower stress distribution across the adhesive layer and better aerodynamic surfaces compared to other bonded joints. The main objective of this study is to evaluate the performance of the scarf adhesive joints in carbon fiber reinforced epoxy composites under thermomechanical impact loads, which is very important for the aerospace and automotive industries. The adhesive was modified with optimum percentage of multiwalled carbon nanotubes. The impact tests were performed at 25 ℃, 50 ℃, and 75 ℃. The residual flexural properties of the unfailed impacted joints were measured using three-point bending test. Results from impact tests at 25 ℃, 50 ℃, and 75 ℃ showed improvement in the impact bending stiffness of the modified scarf adhesive joints by 8.3%, 7.4%, and 11.8% and maximum contact force by 15.6%, 21.3%, and 18.9%, respectively. The energy at failure of the modified scarf adhesive joints with multiwalled carbon nanotubes was improved by 15.2% and 16.4% respectively at 25 ℃ and 50 ℃. At test temperature of 75 ℃, the scarf adhesive joints have hysteresis load–displacement behavior and energy–time curve with rebound energy of 35% and absorbed (damage) energy of 65%. The residual flexural strength of the modified and unmodified scarf adhesive joints is 98.2% and 86.1% respectively, while their residual moduli have remarkable decrease to 71.7% and 81.3%.

Effect of superelastic shape memory alloy wires on the impact behavior of carbon fiber reinforced in situ polymerized poly(butylene terephthalate) composites

2011 ◽  
Vol 65 (5) ◽  
pp. 863-865 ◽  
Author(s):  
J. Aurrekoetxea ◽  
J. Zurbitu ◽  
I. Ortiz de Mendibil ◽  
A. Agirregomezkorta ◽  
M. Sánchez-Soto ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Impact Behavior ◽  
Fiber Reinforced ◽  
Butylene Terephthalate ◽  
Carbon Fiber Reinforced ◽  
The Impact

scholarly journals Dynamic analysis of hybrid basalt and carbon fiber reinforced Bismaleimide composites suited for high temperature structural applications

2021 ◽  
Vol 8 (12) ◽  
pp. 125302
Author(s):  
N Prasanaa Iyer ◽  
N Arunkumar
Keyword(s):  
Carbon Fiber ◽  
Composite Laminates ◽  
Basalt Fiber ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Structural Applications ◽  
Carbon Fiber Reinforced ◽  
The Impact

Abstract The main aim of this work is to study thedamage tolerance of hybrid basalt and carbon fiber-reinforced composite subjected to low velocity impact (LVI) at different velocities, 2.89 m s−1 and 4.42 m s−1, simulated using a CEAST drop hammer testing machine and Dynamic Mechanical Analysis(DMA) were conducted to characterize the sample. In this article, the detailed failure mechanism of seven composite laminates (Basalt fiber/Bismaleimide(BMI)-diallyl Bisphenol A(DABA), Carbon fiber/BMI-DABA, Carbon and basalt fiber(hybrid fibers)/BMI-DABA) were studied under loading of LVI. Through the experiment, it was also substantiated that the hybrid fiber-reinforced composites possessed better damage tolerance and thermo mechanical properties than the homogenous fiber-reinforced composites. The hybrid fiber composites that were produced vary in the number of carbon fiber to basalt fiber ratio and stacking sequence. The impacted surface was analyzed at macro level by using Image J software. The impact force, the energy absorbed, and the deformation of the laminates under impact load were scrutinized extensively, and it was inferred that the basalt fiber intercalated with carbon fiber with BMI/DABA possessed the highest damage resistance than the other composite laminates under study. The highest peak force 5702 N and 9241 N with the highest elastic energy 4.8 J, 11.7 J and with lower deformation (3.85 mm, 6.09 mm) and deformation area (22.79 mm2, 28.09 mm2) was observed in the intercalated hybrid laminate.

scholarly journals Optimization Simulation of the Light Aircraft’s Cockpit Made of Carbon Fiber Reinforced Composites

2017 ◽  
Author(s):  
Pu-Woei Chen ◽  
Chia-Hung Liu
Keyword(s):  
Aluminum Alloy ◽  
Topology Optimization ◽  
Carbon Fiber ◽  
Energy Absorption ◽  
Fiber Reinforced Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Carbon Fiber Reinforced Composites ◽  
Carbon Fiber Reinforced ◽  
The Impact

Due to the demands of personal travels and entertainments, light airplanes and small business aircrafts are developing rapidly. Light airplane structure is simple; however, it lacks crashworthiness design, especially the considerations on the impact of energy absorption. Therefore, in an event of accident, significant damage to passengers will be usually incurred. Airplanes made of composite materials structurally have high specific strength and good aerodynamic configuration. These materials have become the primary choice for new airplane development. This study mainly explores the topology optimization analysis of the light aircraft’s cockpit made of carbon fiber reinforced composites. This paper compares the compression amounts in the original models of composite material and aluminum alloy fuselages with the models after optimization during the crash-landing, in order to investigate the safety of fuselages made of different materials after structural optimization under the dynamic crashing. This study found that the energy absorbed by the aluminum alloy fuselage during crash-landing is still higher than that by the carbon fiber reinforced composites fuselage. On the other hand, the aluminum alloy fuselage after topology optimization could have an energy absorption capability enhanced by 40%, as compared to the that of the original model of aluminum alloy fuselage.

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