Vibration correlation technique for predicting the buckling load of imperfection-sensitive isotropic cylindrical shells: An analytical and numerical verification

Franzoni, Felipe; Degenhardt, Richard; Albus, Jochen; Arbelo, Mariano A.

doi:10.1016/j.tws.2019.03.041

Cited by 31 publications

(25 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The functional form of Equation (2), with C 2 = C 0 =1 and C 1 = −2, has been noted to comply with that of a perfect simply supported shell given by Equation (1), and Equation (3) shown to provide a correct buckling condition of f m = 0 in such a case [ 24 ]. A similar derivation for a clamped shell has been performed in [ 32 ].…”

Section: Empirical Vct Techniquesmentioning

confidence: 99%

“…A graphical interpretation of the procedure is as follows [ 23 ]: the experimental load–natural frequency data are presented as a plot of (1 − P / P cr ) 2 versus 1 − ( f m / f 0 ) 2 , the data points are approximated by fitting a second-order polynomial, the minimum value of this polynomial, ξ 2 , is found, and the VCT estimate of the buckling load P VCT is obtained from the equality 1 − P VCT / P cr = ξ . The described approach has also been validated numerically [ 24 ], although only considering one specific imperfection group, namely, geometrical imperfections.…”

Section: Introductionmentioning

confidence: 99%

“…However, a sufficiently detailed characterization of shell imperfections may be overly complicated in industrial applications. The advantage of VCT is that only a relatively uncomplicated nondestructive mechanical test of a shell is required [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ] instead of a detailed inspection of different imperfections of the shell. However, the boundary conditions of the structural element have to be accurately recreated in the shell test.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Robustness of Empirical Vibration Correlation Techniques for Predicting the Instability of Unstiffened Cylindrical Composite Shells in Axial Compression

et al. 2020

View full text Add to dashboard Cite

Thin-walled carbon fiber reinforced plastic (CFRP) shells are increasingly used in aerospace industry. Such shells are prone to the loss of stability under compressive loads. Furthermore, the instability onset of monocoque shells exhibits a pronounced imperfection sensitivity. The vibration correlation technique (VCT) is being developed as a nondestructive test method for evaluation of the buckling load of the shells. In this study, accuracy and robustness of an existing and a modified VCT method are evaluated. With this aim, more than 20 thin-walled unstiffened CFRP shells have been produced and tested. The results obtained suggest that the vibration response under loads exceeding 0.25 of the linear buckling load needs to be characterized for a successful application of the VCT. Then the largest unconservative discrepancy of prediction by the modified VCT method amounted to ca. 22% of the critical load. Applying loads exceeding 0.9 of the buckling load reduced the average relative discrepancy to 6.4%.

show abstract

Section: Empirical Vct Techniquesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Robustness of Empirical Vibration Correlation Techniques for Predicting the Instability of Unstiffened Cylindrical Composite Shells in Axial Compression

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Natural frequency vs. hydrostatic pressure characteristic is useful for predicting critical buckling pressure of shells using vibration correlation technique 21,22 . It is a non-destructive technique for predicting the critical buckling pressure.…”

Section: Modal Testing Under Hydrostatic Pressurementioning

confidence: 99%

Study of Vibration Behaviour of Stiffened Polymer Composite Shells for Underwater Structural Applications

Patil¹,

Murthy²,

Srivatsa³

et al. 2020

Def. Sc. Jl.

View full text Add to dashboard Cite

This paper presents vibration behavior of ring stiffened polymer composite thick shells used for underwater structures. Filament wound shells stiffened with internal and external rings and with hemispherical ends were tested for vibration in air and water in free-free boundary condition using roving hammer and fixed response method. Modal testing of the shells was performed under hydrostatic loading in a custom designed buckling tester for determining natural frequency at higher sea depths. Accelerometer was mounted on the inner surface of the shell. It was excited using a plumbob, rope and pulley arrangement. Experimental results were validated by modal analysis using Hyperworks and ANSYS. Vibration behavior in water was simulated by Fluid structure interaction approach. Experimental first natural frequency in water was lesser than that in air. With increase in hydrostatic pressure, the shell showed moderate variation in natural frequency. The experimental and numerical results of natural frequency and mode shapes were in good agreement with each other. Natural frequencies were lower in long and thick shells.

show abstract

“…Franzoni et al [ 12 ] presented various modifications to the standard relationship between vibrations and buckling proposed by researchers throughout the years.…”

Section: Introductionmentioning

confidence: 99%

Impact of Geometrical Imperfections on Estimation of Buckling and Limit Loads in a Silo Segment Using the Vibration Correlation Technique

Żmuda-Trzebiatowski

Iwicki

2021

Materials

View full text Add to dashboard Cite

The paper examines effectiveness of the vibration correlation technique which allows determining the buckling or limit loads by means of measured natural frequencies of structures. A steel silo segment with a corrugated wall, stiffened with cold-formed channel section columns was analysed. The investigations included numerical analyses of: linear buckling, dynamic eigenvalue and geometrically static non-linear problems. Both perfect and imperfect geometries were considered. Initial geometrical imperfections included first and second buckling and vibration mode shapes with three amplitudes. The vibration correlation technique proved to be useful in estimating limit or buckling loads. It was very efficient in the case of small and medium imperfection magnitudes. The significant deviations between the predicted and calculated buckling and limit loads occurred when large imperfections were considered.

show abstract

Vibration correlation technique for predicting the buckling load of imperfection-sensitive isotropic cylindrical shells: An analytical and numerical verification

Cited by 31 publications

References 17 publications

Robustness of Empirical Vibration Correlation Techniques for Predicting the Instability of Unstiffened Cylindrical Composite Shells in Axial Compression

Robustness of Empirical Vibration Correlation Techniques for Predicting the Instability of Unstiffened Cylindrical Composite Shells in Axial Compression

Study of Vibration Behaviour of Stiffened Polymer Composite Shells for Underwater Structural Applications

Impact of Geometrical Imperfections on Estimation of Buckling and Limit Loads in a Silo Segment Using the Vibration Correlation Technique

Contact Info

Product

Resources

About