scholarly journals Experimental and Finite Element Studies on Free Vibration of Skew Plates

2014 ◽  
Vol 19 (2) ◽  
pp. 365-377 ◽  
Author(s):  
C.V. Srinivasa ◽  
Y.J. Suresh ◽  
W.P. Prema Kumar
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Free Vibration ◽  
Composite Laminates ◽  
Natural Frequencies ◽  
Experimental Studies ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Skew Angle ◽  
Experimental Values

Abstract The present paper deals with the experimental studies carried out on free vibration of isotropic and laminated composite skew plates. The natural frequencies were also determined using QUAD8 finite element of MSC/NASTRAN and a comparison was made between the experimental values and the finite element solution. The effects of the skew angle and aspect ratio on the natural frequencies of isotropic skew plates were studied. The effects of the skew angle, aspect ratio, fiber orientation angle and laminate sequence (keeping the number of layers constant) on the natural frequencies of antisymmetric composite laminates were also studied. The experimental values of natural frequencies are in good agreement with the FE solutions. The natural frequencies are found to increase with an increase in the skew angle. The variation of natural frequencies with the aspect ratio is small and negligible both for isotropic and laminated composite skew plates.

scholarly journals Modal Characterization of Sandwich Skew Plates

2021 ◽  
Vol 15 (3) ◽  
pp. 143-153
Author(s):  
Dhotre Pavan Kumar ◽  
Chikkol V. Srinivasa
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Edge Condition ◽  
Skew Angle ◽  
Composite Sandwich ◽  
Fiber Orientation Angle ◽  
Experimental Values ◽  
Element Free

Abstract The current work focuses on the experimental and finite element free vibration studies of laminated composite sandwich skew plates. The comparison was made between the experimental values obtained by the Fast Fourier transform (FFT) analyzer and a finite element solution obtained from CQUAD8 finite element of The MacNeal-Schwendler Corporation (MSC) / NASA STRucture Analysis (NASTRAN) software. The influence of parameters such as aspect ratio (AR) (a/b), skew angle (α), edge condition, laminate stacking sequence, and fiber orientation angle (θ°) on the natural frequencies of sandwich skew plates was studied. The values obtained by both the finite element and experiment approaches are in good agreement. The natural frequencies increase with an increase in the skew angle for all given ARs.

scholarly journals Finite Element Studies on Free Vibration of Laminated Composite Cylindrical Skew Panels

2014 ◽  
Vol 6 ◽  
pp. 174085
Author(s):  
Srinivasa Chikkol Venkateshappa ◽  
Suresh Yalaburgi Jayadevappa ◽  
Premakumar Wooday Puttiah
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Fundamental Frequency ◽  
Composite Laminates ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Skew Angle ◽  
Element Analysis ◽  
Number Of Layers ◽  
Fiber Orientation Angle

This paper presents the finite element studies made on free vibration of isotropic and laminated composite cylindrical skew panels. A finite element analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN software. The effects of the panel angle, skew angle, aspect ratio, and length-to-thickness-ratio on fundamental natural frequency of vibration of isotropic cylindrical skew panels are studied. The effects of additional parameters such as fiber orientation angle, numbers of layers (keeping total thickness constant), and laminate stacking sequence on the fundamental frequency of vibration of antisymmetric composite laminates have also been studied. During validation and convergence study, it is found that the CQUAD8 element yields more accurate results than the CQUAD4 element. Hence the CQUAD8 element has been employed for the remaining part of the investigation. The fundamental frequency is found to increase with the panel angle and skew angle. The variation of the fundamental frequency with the number of layers is not appreciable when the number of layers is greater than about 6. It is also seen that the boundary conditions have significant influence on the fundamental frequency.

scholarly journals Finite element studies on free vibration of laminated composite cylindrical skew panels

2014 ◽  
Vol 19 (1) ◽  
pp. 165-180
Author(s):  
C.V. Srinivasa ◽  
Y.J. Suresh ◽  
W.P. Prema Kumar
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Fundamental Frequency ◽  
Composite Laminates ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Skew Angle ◽  
Fundamental Frequencies ◽  
Number Of Layers ◽  
Fiber Orientation Angle

Abstract This paper presents the finite element studies on free vibration of isotropic and laminated composite cylindrical skew panels. The analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN. The effects of the panel angle, skew angle, aspect ratio and length-to-thickness-ratio on fundamental frequency of isotropic cylindrical skew panels are studied. The effects of additional parameters such as the fiber orientation angle, numbers of layers and stacking sequence on the fundamental frequency of antisymmetric composite laminates are also studied. It is found that the CQUAD8 element yields better results than the CQUAD4 element in the validation and convergence studies. The CQUAD8 element is employed for the remaining part of the studies. The fundamental frequencies are found to increase with the panel angle and skew angle. When the number of layers in the laminate is large, the variation of the fundamental frequency with the number of layers is not appreciable. The boundary conditions are found to have a significant influence on the fundamental frequency

Buckling of laminated composite cylindrical skew panels

2015 ◽  
Vol 30 (9) ◽  
pp. 1175-1199
Author(s):  
Srinivasa Venkateshappa Chikkol ◽  
Prema Kumar Puttiah Wooday ◽  
Suresh Jayadevappa Yelaburgi
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Laminated Composite ◽  
Buckling Load ◽  
Finite Element Solution ◽  
Element Solution ◽  
Skew Angle ◽  
Critical Buckling Load ◽  
Aluminum 7075 ◽  
Experimental Values

Experimental studies were made on isotropic cylindrical skew panels made of Aluminum 7075-T6 and laminated composite cylindrical skew panels under uniaxial compression. The experimental values of the critical buckling load ( Pcr) were determined using five different methods. The values of Pcr were also determined using MSC/Nastran and CQUAD8 finite element. The experimental values of the Pcr obtained by different methods were compared with the finite element solution. The effects of the skew angle and aspect ratio on the critical buckling load of isotropic cylindrical skew panels made of Aluminum 7075-T6 were studied. The effects of the skew angle, aspect ratio, and the laminate stacking sequence on the critical buckling load of laminated composite cylindrical skew panels were also studied. It is found that the method IV (based on a plot of applied load ( P) vs. average axial strain) yields the highest value for Pcr and method III (based on a plot of P vs. square of out-of-plane-deflection) the lowest value for Pcr. The experimental values given by method IV are seen to be closest to the finite element solution, the discrepancy being in the range of 5–23% for laminated composite cylindrical skew panels. For isotropic panels, it is found that the value Pcr initially increases with an increase in the skew angle and later decreases as the skew angle increases beyond 15°. For laminated composite panels, the Pcr value decreases as the aspect ratio increases for all laminate stacking sequences.

Experimental and finite element studies on buckling of skew plates under uniaxial compression

2015 ◽  
Vol 22 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Srinivasa Chikkol Venkateshappa ◽  
Suresh Yalaburgi Jayadevappa ◽  
Prema Kumar Wooday Puttiah
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Uniaxial Compression ◽  
Laminated Composite ◽  
Buckling Load ◽  
Element Solution ◽  
Skew Angle ◽  
Critical Buckling Load ◽  
Aluminum 7075 ◽  
Experimental Values

AbstractExperimental studies were made on isotropic skew plates made of aluminum 7075-T6 and laminated composite skew plates under uniaxial compression with unloaded edges completely free and one loaded edge restrained completely and the other loaded edge restrained except translationally in the direction of loading. Experimental values of the buckling load have been determined using five different methods. The buckling load has also been determined using CQUAD8 finite element of MSC/NASTRAN. Comparison is made between the various experimental values of buckling load and the finite element solution. The effects of the skew angle and the aspect ratio on the critical buckling load of isotropic skew plates made of aluminum 7075-T6 have been studied. The effects of the skew angle, aspect ratio, and the laminate stacking sequence on the critical buckling load of laminated composite skew plates have also been studied. The critical buckling load is found to increase with the increase in the skew angle and decrease with the increase in aspect ratio. Method IV yields the highest value for critical buckling load and Method III the lowest value for critical buckling load. Among the various experimental values, the one given by Method IV is closest to the finite element solution, and the discrepancy between them is less than about 5% in the case of isotropic skew plates and about 10–15% in the case of laminated composite skew plates.

scholarly journals The Effect of Various Fiber Orientations and Boundary Conditions on Natural Frequencies of Laminated Composite Beam

2018 ◽  
Vol 7 (3.11) ◽  
pp. 67 ◽  
Author(s):  
M Arif Mat Norman ◽  
M Amiruddin Zainuddin ◽  
Jamaluddin Mahmud
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
Aspect Ratio ◽  
Free Vibration ◽  
Boundary Conditions ◽  
Composite Beam ◽  
Natural Frequencies ◽  
Laminated Composite ◽  
Mode Shapes ◽  
Laminated Composite Beam

This paper investigates the free vibration characteristics of laminate composite beam for various lamination schemes and under various boundary conditions. A beam model with the aspect ratio (length to thickness) of 25 to 150 made of carbon/ epoxy laminates under free vibration were constructed using a commercially available finite element software (ANSYS). The varied parameters are the lamination schemes (cross ply, angle ply and unidirectional ply) and boundary conditions (Clamp-Free (C-F), Clamp-Clamp (C-C), Clamp-Hanger (C-H), Free-Free (F-F) and Hanger-Hanger (H-H) ). For each case, finite element simulations were performed and the natural frequencies were determined. Mode shapes were also analyzed to observe the beam’s deformation behavior. Results showed that increasing aspect ratio will decrease natural frequencies for the first seven mode shapes. In terms of lamination scheme, the unidirectional ply produced the highest frequency (34.26 Hz), followed by cross ply (34.05 Hz) and angle ply (13.60 Hz) at the aspect ratio of 25. In terms of boundary conditions, the Hanger-Hanger boundary condition produced the highest natural frequency (2272.52  Hz) at the aspect ratio of 25, while Clamped-Free boundary condition produced the lowest frequency (2.28 Hz) at the aspect ratio of 150. In general, it can be concluded that the current study is useful and has contributed significant knowledge to better understand of effect of various fiber orientations and boundary conditions on the natural frequencies of laminated composite beam. 

scholarly journals Vibration Analysis of Carbon Fiber Reinforced Laminated Composite Skin with Glass Honeycomb Sandwich Beam Using HSDT

2017 ◽  
Vol 61 (3) ◽  
pp. 213 ◽  
Author(s):  
Mageshwaran Subramani ◽  
Ananda Babu Arumugam ◽  
Manoharan Ramamoorthy
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Sandwich Beam ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Sandwich ◽  
The Core ◽  
Core Thickness

In this paper, the vibration analysis of uniform laminated composite sandwich beam with a viscoelastic core was studied. The governing equation of motion of the laminated composite sandwich beam has been derived based on higher order shear deformation theory (HSDT) in finite element model (FEM). The developed finite element model has been validated in terms of natural frequencies with the experimental values and the available literature. Various parametric studies have been performed to examine the impact of the core thickness, ply orientation and aspect ratio of the uniform laminated composite sandwich beam in response to free vibration for various boundary conditions. From the results it was concluded that that natural frequencies could be increased with increasing the core thickness and decreased with increasing the aspect ratio.

Finite element studies on buckling of laminated cylindrical skew panels

2014 ◽  
Vol 21 (4) ◽  
pp. 551-558 ◽  
Author(s):  
Chikkol Venkateshappa Srinivasa ◽  
Yalaburgi Jayadevappa Suresh ◽  
Wooday Puttiah Prema Kumar
Keyword(s):  
Finite Element ◽  
Fiber Orientation ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Buckling Load ◽  
Stacking Sequence ◽  
Skew Angle ◽  
Buckling Loads ◽  
Critical Buckling Load ◽  
Fiber Orientation Angle

AbstractThe present paper presents the finite element studies made on critical buckling load of isotropic and laminated composite cylindrical skew panels. Analysis is performed using CQUAD4 and CQUAD8 elements of MSC/NASTRAN. It is found that the CQUAD8 element yields better results compared to the CQUAD4 element in terms of accuracy and convergence. Using the CQUAD8 element, the effects of the panel angle, skew angle, aspect ratio, and length-to-thickness ratio on the critical buckling load of isotropic cylindrical skew panels have been studied. The effects of additional parameters such as fiber orientation angle, numbers of layers (NL), and stacking sequence on the critical buckling load of laminated composite cylindrical skew panels have also been studied. The critical buckling loads are found to increase with the increase in panel angle and skew angle. When the NL in the laminate is large, the variation of the critical buckling load with the NL is not appreciable. The boundary conditions are found to have significant influence on the critical buckling load.

Free Vibration of Rectangular Composite Laminates With Delamination

2007 ◽  
Author(s):  
L. C. Shiau ◽  
S. T. Hwang
Keyword(s):  
Aspect Ratio ◽  
Free Vibration ◽  
Composite Laminates ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Considerable Effect ◽  
Finite Strip ◽  
Finite Strip Method ◽  
Natural Modes ◽  
Contact Impact

In this paper, the effect of delamination on natural frequencies and natural modes of a simply supported rectangular symmetric composite plate with through-width delamination was investigated by the finite strip method. The delamination was assumed to be located at mid-plane of the laminate so that the contact/impact phenomenon between delaminated interfaces does not exist for the free vibration of the laminate. A finite strip with bending and in-plane stiffnesses was derived for the free vibration analysis. The effects of delamination length, delamination location, fiber angle, stacking sequence, and aspect ratio of the laminate on the natural frequencies of the laminate were studied and presented. Results show that the above mentioned factors have considerable effect on the natural frequencies of the laminate. The aspect ratio of the plate is also having significant effect on the frequency of the laminates, especially on the mode 2 frequency of the cross-ply laminate.

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.

Sign in / Sign up

Export Citation Format

Share Document