Free-Vibration Analysis of Clamped Antisymmetrically Laminated Elliptical Plates

1998 ◽  
Vol 65 (2) ◽  
pp. 341-345 ◽  
Author(s):  
K. Hosokawa ◽  
Y. Yamada ◽  
T. Sakata
Keyword(s):  
Free Vibration ◽  
Natural Frequency ◽  
Mode Shape ◽  
Orientation Angle ◽  
Free Vibration Analysis ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Plastic Composite ◽  
Reinforced Plastic

In a previous paper, a numerical approach for analyzing the free vibration problem of an unsymmetrically laminated fiber-reinforced plastic composite plate was proposed by the authors. In the present paper, this approach is applied to the clamped antisymmetrically laminated elliptical plate. As numerical examples, the natural frequencies and the mode shapes of the circular and elliptical plates are estimated. The effects of the fiber orientation angle on natural frequency and mode shape are studied. Furthermore, the vibration tests of the clamped antisymmetrically laminated circular and elliptical plates made of carbon fiber-reinforced plastic are carried out, and the experimental natural frequency and mode shape are compared with the numerical results.

scholarly journals Comparison of Mode Shapes of Carbon-Fiber-Reinforced Plastic Material Considering Carbon Fiber Direction

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 311
Author(s):  
Chan-Jung Kim
Keyword(s):  
Carbon Fiber ◽  
Modal Analysis ◽  
Dynamic Behavior ◽  
Mode Shapes ◽  
Modal Parameters ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Direction ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic

Previous studies have demonstrated the sensitivity of the dynamic behavior of carbon-fiber-reinforced plastic (CFRP) material over the carbon fiber direction by performing uniaxial excitation tests on a simple specimen. However, the variations in modal parameters (damping coefficient and resonance frequency) over the direction of carbon fiber have been partially explained in previous studies because all modal parameters have only been calculated using the representative summed frequency response function without modal analysis. In this study, the dynamic behavior of CFRP specimens was identified from experimental modal analysis and compared five CFRP specimens (carbon fiber direction: 0°, 30°, 45°, 60°, and 90°) and an isotropic SCS13A specimen using the modal assurance criterion. The first four modes were derived from the SCS13A specimen; they were used as reference modes after verifying with the analysis results from a finite element model. Most of the four mode shapes were found in all CFRP specimens, and the similarity increased when the carbon fiber direction was more than 45°. The anisotropic nature was dominant in three cases of carbon fiber, from 0° to 45°, and the most sensitive case was found in Specimen #3.

scholarly journals Effects of Elliptical Hole on the Correlation of Natural Frequency with Buckling Load of Basalt Laminates Composite Plates

2020 ◽  
Vol 27 (1) ◽  
pp. 216-225
Author(s):  
Buntheng Chhorn ◽  
WooYoung Jung
Keyword(s):  
Free Vibration ◽  
Natural Frequency ◽  
Natural Frequencies ◽  
Basalt Fiber ◽  
Orientation Angle ◽  
Elliptical Hole ◽  
Composite Plates ◽  
Buckling Load ◽  
Mode Shapes ◽  
Geometric Ratio

AbstractRecently, basalt fiber reinforced polymer (BFRP) is acknowledged as an outstanding material for the strengthening of existing concrete structure, especially it was being used in marine vehicles, aerospace, automotive and nuclear engineering. Most of the structures were subjected to severe dynamic loading during their service life that may induce vibration of the structures. However, free vibration studied on the basalt laminates composite plates with elliptical cut-out and correlation of natural frequency with buckling load has been very limited. Therefore, effects of the elliptical hole on the natural frequency of basalt/epoxy composite plates was performed in this study. Effects of stacking sequence (θ), elliptical hole inclination (ϕ), hole geometric ratio (a/b) and position of the elliptical hole were considered. The numerical modeling of free vibration analysis was based on the mechanical properties of BFRP obtained from the experiment. The natural frequencies as well as mode shapes of basalt laminates composite plates were numerically determined using the commercial program software (ABAQUS). Then, the determination of correlation of natural frequencies with buckling load was carried out. Results showed that elliptical hole inclination and fiber orientation angle induced the inverse proportion between natural frequency and buckling load.

scholarly journals Recycling of Waste Fiber-Reinforced Plastic Composites: A Patent-Based Analysis

Recycling ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 72
Author(s):  
Beatrice Colombo ◽  
Paolo Gaiardelli ◽  
Stefano Dotti ◽  
Flavio Caretto ◽  
Gaetano Coletta
Keyword(s):  
Future Development ◽  
Industrial Applications ◽  
Growth Potential ◽  
Chemical Recycling ◽  
Fiber Reinforced ◽  
Mechanical Recycling ◽  
Fiber Reinforced Plastic ◽  
Technology Roadmap ◽  
Plastic Composite ◽  
Reinforced Plastic

Fiber-reinforced plastic composite materials are increasingly used in many industrial applications, leading to an increase in the amount of waste that must be treated to avoid environmental problems. Currently, the scientific literature classifies existing recycling technologies into three macro-categories: mechanical, thermal, and chemical; however, none are identified as superior to the others. Therefore, scholars and companies struggle to understand where to focus their efforts. Patent analysis, by relying on quantitative data as a precursor to new technological developments, can contribute to fully grasping current applications of each recycling technology and provide insights about their future development perspectives. Based on these premises, this paper performs a patent technology roadmap to enhance knowledge about prior, current, and future use of the main recycling technologies. The results show that recycling macro-categories have different technology maturity levels and growth potentials. Specifically, mechanical recycling is the most mature, with the lowest growth potential, while thermal and chemical recycling are in their growth stage and present remarkable future opportunities. Moreover, the analysis depicts several perspectives for future development on recycling technologies applications within different industries and underline inter- and intra-category dependencies, thus providing valuable information for practitioners and both academic and non-academic backgrounds researchers interested in the topic.

Enhancement of vibration characteristics in filament wound FRP composite shafts using nitinol wires

2018 ◽  
Vol 47 (5) ◽  
pp. 377-385 ◽  
Author(s):  
Kannan Murugesan ◽  
Kalaichelvan K. ◽  
M.P. Jenarthanan ◽  
Sornakumar T.
Keyword(s):  
Natural Frequency ◽  
Damping Ratio ◽  
Filament Winding ◽  
Fiber Reinforced ◽  
Content Type ◽  
Fiber Reinforced Plastic ◽  
Damping Characteristics ◽  
Filament Wound ◽  
Reinforced Plastic ◽  
Hollow Shafts

Purpose The purpose of this paper is to investigate the use of embedded Shape Memory Alloy (SMA) nitinol wire for the enhancement of vibration and damping characteristics of filament-wound fiber-reinforced plastic composite hollow shafts. Design/methodology/approach The plain Glass Fiber-Reinforced Plastic (GFRP) and plain Carbon Fiber-Reinforced Plastic (CFRP) hollow shafts were manufactured by filament winding technique. Experimental modal analysis was conducted for plain hollow shafts of C1045 steel, GFRP and CFRP by subjecting them to flexural vibrations as per ASTM standard C747, with both ends clamped (C-C) end condition to investigate their vibration and damping behavior in terms of first natural frequency, damping time and damping ratio. Nitinol wires pre-stressed at various pre-strains (2, 4 and 6 per cent) were embedded with CFRP hollow shafts following same manufacturing technique, and similar experimental modal analysis was carried out by activating nitinol wires. The first natural frequencies of all the shaft materials were also predicted theoretically and compared with experimental measurements. Findings Among the three materials C1045 steel, plain GFRP and plain CFRP, the vibration and damping behavior were found to be the best for plain CFRP. Hence, CFRP shafts were considered for further improvement by embedding nitinol wires at pre-stressed condition. For CFRP shafts embedded with nitinol wires, the damping time decreased; and damping ratio and first natural frequency increased with increase in percentage of pre-strain. In comparison with plain CFRP, 7 per cent increase in first natural frequency and 100 per cent increase in damping ratio were observed for nitinol embedded CFRP shafts with 6 per cent pre-strain. Theoretical predictions of the first natural frequencies agree well with the experimental results for all the shaft materials. Originality/value The effect of nitinol on vibration and damping characteristics of filament wound hollow CFRP composite shafts with different pre-strains has not been studied extensively by the previous researchers. This paper addresses the effect of embedded nitinol wires pre-stressed at three varied pre-strains, that is, 2, 4 and 6 per cent on the vibration and damping characteristics of composite hollow CFRP shafts manufactured by filament winding technique.

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