Novel development of dynamic behavior of carbon fiber reinforced polymer sandwich panels with stepwise graded adhesive layer

2018 ◽  
Vol 91 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Majed Mokhtari ◽  
M. Shahravy ◽  
M. Zabihpoor
Keyword(s):  
Dynamic Loading ◽  
Sandwich Panel ◽  
Adhesive Layer ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Structural Damping ◽  
Content Type ◽  
Transient Dynamic ◽  
Reinforced Polymer ◽  
Homogenous Case

Purpose The purpose of this study is to focus on the developments of carbon fiber reinforced polymer (CFRP) panels with stepwise graded properties on adhesive layer. The various arranges of the graded properties of the adhesive layer have been checked according to experimental results of the literatures and based on applicability. Design/methodology/approach The finite element (FE) models and experimental modal tests of the manufactured CFRP sandwich panel specimens have been investigated. The core thickness, core density and orientation of the fiber direction of the sandwich panel face – sheets have been parametrically checked based on modal behavior. Two fully free and fully clamped boundary conditions (BC) have been checked in stepwise graded adhesive zone (SGAZ) cases and first five non-zero natural frequencies (NF) have been compared. Dynamic response of the SGAZ includes modal analysis and transient dynamic loading have been performed numerically with ABAQUS 6.12 well-known FE code. Findings The first non-zero NF of SGAZ Case 4 was 11.69 per cent higher than homogenous Case 2 and 7.06 per cent lower than Case 1 in fully free boundary conditions. A total of 26.38 per cent is the greatest discrepancy between fist five non-zero NFs of all cases with two BCs (Case 1 vs Case 2 in fully clamped BC). Maximum structural damping behavior and minimum stress picks have been studied during transient dynamic loading analysis of CFRP panel with SGAZ. SGAZ Case 3 (middle adhesive with lower modulus) has increased the maximum structural damping while reducing the minimum out of plain tip displacements during transient dynamic loading by 111.26 per cent in comparison with homogenous Case 2. Also, Case 3 has reduced the Mises stress picks on the adhesive region by 605.68 per cent. Practical implications Making a stepwise graded adhesive region (without any added mass) has been shown that it is a novel and useful way to achieve a wide range of stiffness on CFRP panels. Originality/value Development of the sandwich panels with various stiffness and damping properties.

Investigation of crevice corrosion of metallic fastened joints in carbon fiber reinforced polymer (CFRP) exposed to coastal seawater

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammed I. Abdulsalam ◽  
Francisco Presuel-Moreno
Keyword(s):  
Corrosion Resistance ◽  
Carbon Fiber ◽  
Carbon Fibers ◽  
Crevice Corrosion ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Content Type ◽  
Coastal Seawater ◽  
High Impedance ◽  
Reinforced Polymer

Purpose The purpose of this paper is to study the susceptibility of these three commonly used corrosion resistance fasteners in seawater. For a more practical scenario, a local Atlantic coastal seawater as received was used. Design/methodology/approach Carbon fiber reinforced polymer (CFRP) was fabricated with T700 carbon fiber (Toray Inc.) and VE8084 vinyl ester resin (Ashland) to make a unidirectional composite panel of thickness 1.8 mm. A conductive paint was applied to one of the sample edges that was perpendicular to the fiber direction, providing an electrical contact with carbon fibers to connect a copper wire. This external electric connection was used for potential measurements of both the open circuit potential (OCP) of the CFRP sample, and the mixed potential of the fastened set: consisting of the CFRP and the metallic fastener fastened to it. Three common fastener alloys were selected: 316SS, Monel and Titanium. For this purpose, a high impedance voltmeter was used in conjunction with a saturated calomel reference electrode. Measurements were taken daily. For longer time measurements, a four-channel high impedance analog data logger was used with 30 min sampling rate. Findings For both 316SS and Monel fastened sets, crevice corrosion occurred inside the occluded regions of the set, when immersed in coastal seawater. The attack was more severe for 316 stainless steel set. An isolated island attack of faceted surfaces morphology was seen for 316SS set. While, a circular ring of preferential grain boundary attack appeared for Monel set, indicating an IR (voltage) drop mechanism is more likely operating. Titanium-fastened sets showed high resistance to crevice corrosion when simmered in seawater. However, for long-time exposure, the sets became more susceptible to crevice corrosion attack supported by CFRP attachment (oxygen reduction reaction taking place at the carbon fibers). Originality/value Evidently, titanium, stainless steels and Monel are good candidates for galvanic corrosion resistance. However, their susceptibility to crevice corrosion when coupled with CFRP is a new challenging topic that needs further investigation. This is very important today because the vast application witnessed for CFRP material. This work involves developing an original methodology for this kind of investigation and was done at advanced laboratories of SeaTech at Florida Atlantic University by the Atlantic coastline.

scholarly journals Modeling and Assessment of Rotation and Gravity in a Piezoelectric Viscothermoelastic Multilayered Composite LEMV / CFRP Cylinder

2021 ◽  
Vol 8 (4) ◽  
pp. 611-616
Author(s):  
Jeyaraman Poongkothai ◽  
Samydurai Mahesh ◽  
Rajendran Selvamani
Keyword(s):  
Gravitational Force ◽  
Adhesive Layer ◽  
Theory Of Elasticity ◽  
Fiber Reinforced Polymer ◽  
Wave Number ◽  
Carbon Fiber Reinforced Polymer ◽  
Phase Lag ◽  
Linear Elastic ◽  
Reinforced Polymer ◽  
Lag Model

A mathematical model is developed to analysis the effects of gravitational force and rotation in a composite multilayered hollow cylinder which contain inner and outer piezo-thermoelasticity layers bonded by Linear Elastic Material with Voids (LEMV) is performed within the frame of dual-phase-lag model. The equation of displacement components, temperature, and electric are obtained using linear theory of elasticity. The dispersion equations are derived based on traction free boundary conditions and are numerically examined for CdSe material. The enumerated frequency, thermal and electrical nature against wave number is presented graphically. Adhesive layer LEMV is compared with Carbon Fiber Reinforced Polymer (CFRP) in the presence of gravity and rotation.

Investigation and optimization of machining parameters in drilling of carbon fiber reinforced polymer (CFRP) composites

2017 ◽  
Vol 46 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Shunmugesh K. ◽  
Panneerselvam Kavan
Keyword(s):  
Surface Roughness ◽  
Cutting Speed ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Direction ◽  
Machining Parameters ◽  
Taguchi Technique ◽  
Content Type ◽  
Reinforced Polymer ◽  
Delamination Factor

Purpose This paper aims to attempt to use grey relational analysis (GRA) coupled with Taguchi technique for the optimization of machining parameters (cutting speed, feed rate and drill bit type) with multiple performance characteristics of delamination factor, surface roughness and circularity in drilling of carbon fiber-reinforced polymer (CFRP) along the fiber direction. Design/methodology/approach Machining trials involved drilling of 6-mm diameter holes on 8-mm-thick CFRP plates was performed according to L27 (313) Taguchi’s orthogonal array technique using the drill material of high speed steel (HSS), Titanium Nitride (TiN) and Titanium Aluminium Nitride (TiAlN). Analysis of variance has been used find the effect, percentage contribution and significance of the process parameters, namely, cutting speed, feed rate and drill bit type. Findings The Taguchi technique is combined with the GRA to find the optimum process parameter which minimizes the delamination factor, surface roughness and circularity within the range of parameters investigated. The effective implementation of the hybrid approach helps to produce quality and defect free holes. Originality/value Experimental investigation on delamination factor, surface roughness and circularity in drilling of CFRP along the fiber direction using Taguchi-GRA was seldom reported.

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