Abstract
In this article, a spectral finite element (SFE) model is presented for vibration analysis of a cracked viscoelastic beam subjected to moving loads. The dynamic shape functions are derived from the exact solution of the governing wave equations and are utilized for frequency-domain representation of a moving load. It is considered with either constant velocity or acceleration; then, the force vector for each spectral element is evaluated. The cracked beam is modeled as two segments connected by a massless rotational spring; thus, the beam dynamic stiffness matrix is extracted in frequency domain by considering compatibility conditions at the crack position. The effects of change in velocity and acceleration of moving load, crack parameters, and viscoelastic material properties on the dynamic response of the SFE beam model are investigated. The accuracy of SFE results is compared with that of finite elements. The results show the ascendency of the SFE model, as compared to FEM, for reducing the number of elements and computational effort, but increasing numerical accuracy.
Similar content being viewed by others
Abbreviations
- SFEM:
-
Spectral finite element method
- FEM:
-
Finite element method
- DSM:
-
Dynamic stiffness matrix
- FFT:
-
Fast Fourier transform
- a :
-
Acceleration of moving load (m/s2)
- b :
-
Width of beam (m)
- \({C_{\theta}}\) :
-
crack depth-to-beam height ratio-dependent function for rotational spring
- \({{\varvec{d}}({i\omega})}\) :
-
Spectral nodal displacement (\({4 \times 1}\)) (m, rad)
- \({F({x, i\omega})}\) :
-
Spectral components of loading (N)
- F 0 :
-
Amplitude of moving load (N)
- f 1 :
-
Fundamental frequency of beam (Hz)
- \({{\varvec{f}}_{c}({i\omega})}\) :
-
Equivalent spectral nodal force vector (\({4 \times 1}\)) (N, N m)
- \({{\varvec{f}}_{d} (\omega)}\) :
-
External spectral nodal force vector (\({4\times}\)) (N, N m)
- h :
-
Height of beam (m)
- k :
-
Complex-valued wave number (rad/m)
- L :
-
Length of beam (m)
- \({l_{{\rm c}}}\) :
-
Crack location in beam (m)
- \({l_{{\rm e}}}\) :
-
Length of spectral element (m)
- M(x, t):
-
Bending moment (N m)
- N :
-
Number of harmonic components of DFT
- \({{\varvec{N}}_{{\rm VB}} ({x, i\omega})}\) :
-
Dynamic shape functions for transverse displacement (\({1 \times 4}\))
- P(t):
-
Position of moving load in any spectral element as a general function (m)
- Q(x, t):
-
Transverse shear force (N)
- \({{\varvec{S}}_{{\rm VB}} ({i\omega})}\) :
-
Dynamic stiffness matrix
- t :
-
Time (s)
- V :
-
Velocity of moving load (m/s)
- w(x, t):
-
Transverse displacement (m)
- \({W_{n} ({x; i\omega_{n}})}\) :
-
Spectral components of transverse displacement (m)
- x :
-
Location coordinate (m)
- \({\delta (x)}\) :
-
Dirac delta function
- \({\varepsilon}\) :
-
Depth of crack (m)
- \({\lambda}\) :
-
Crack depth-to-beam height ratio (m/m)
- \({\tau_{{\rm d}}}\) :
-
Viscoelastic coefficient
- \({\omega}\) :
-
Sampling frequency (rad/s)
- FEM:
-
finite element method
- SFEM:
-
spectral finite element method
- DSM:
-
Dynamic stiffness matrix
- \({{\prime}}\) :
-
Partial differentiation with respect to x
- n :
-
Number of harmonic component of sampling
References
Timoshenko S., Young D.H., Weaver W.: Vibration Problems in Engineering, 4th edn. Wiley, New York (1974)
Lee H.P.: Dynamic response of a beam with a moving mass. J. Sound Vib. 191, 289–294 (1996)
Hasheminejad S.M., Rafsanjani A.: Two-dimensional elasticity solution for transient response of simply supported beams under moving loads. Acta Mech. 217, 205–218 (2011)
Fryba L.: Vibration of Solids and Structures Under Moving Loads, 3rd edn. Thomas Telford, Groningen (1999)
Di Paola M., Heuer R., Pirrotta A.: Fractional visco-elastic Euler–Bernoulli beam. Int. J. Solid Struct. 50, 3505–3510 (2013)
Lei Y., Murmu T., Adhikari S., Friswell M.I.: Dynamic characteristics of damped viscoelastic nonlocal Euler–Bernoulli beam. Eur. J. Mech. A Solid 42, 125–136 (2013)
Chondros T.G., Dimarogonas A.D., Yao J.: A continuous cracked beam vibration theory. J. Sound Vib. 215, 17–34 (1998)
Shifrin E.I., Routolo R.: Natural frequencies of a beam with an arbitrary number of cracks. J. Sound Vib. 222, 409–423 (1999)
Lee H.P., Ng T.Y.: Dynamic response of a cracked beam subject to a moving load. Acta Mech. 106, 221–230 (1994)
Mahmoud M.A., Zaid M.A.: Dynamic response of a beam with a crack subject to a moving mass. J. Sound Vib. 256, 591–603 (2002)
Patil D.P., Maiti S.K.: Experimental verification of a method of detection of multiple cracks in beams based on frequency measurements. J. Sound Vib. 281, 439–451 (2005)
Nahvi H., Jabbari M.: Crack detection in beams using experimental modal data and finite element model. Int. J. Mech. Sci. 47, 1477–1497 (2005)
Shafiei M., Khaji N.: Analytical solutions for free and forced vibrations of a multiple cracked Timoshenko beam subject to a concentrated moving load. Acta Mech. 221, 79–97 (2011)
Lin H.P., Chang S.C.: Forced responses of cracked cantilever beams subjected to a concentrated moving load. Int. J. Mech. Sci. 48, 1456–1463 (2006)
Rieker J.R., Trethewey M.W.: Finite element analysis of an elastic beam structure subjected to a moving distributed mass train. Mech. Syst. Signal Process. 13, 31–51 (1999)
Doyle J.F.: Wave Propagation in Structures, 2nd edn. Springer, New York (1997)
Doyle J.F.: A spectrally formulated finite element for longitudinal wave propagation. Int. J. Anal. Exp. Modal Anal. 3, 1–5 (1988)
Doyle J.F., Farris T.N.: A spectrally formulated finite element for flexural wave propagation in beams. Int. J. Anal. Exp. Modal Anal. 5, 13–23 (1990)
Gopalakrishnan S., Martin M., Doyle J.F.: A matrix methodology for spectral analysis of wave propagation in multiple connected Timoshenko beams. J. Sound Vib. 158, 11–24 (1992)
Hajheidari H., Mirdamadi H.R.: Frequency-dependent vibration analysis of symmetric cross-ply laminated plate of Levy-type by spectral element and finite strip procedures. Appl. Math. Model. 37, 7193–7205 (2013)
Hajheidari H., Mirdamadi H.R.: Free and transient vibration analysis of an un-symmetric cross-ply laminated plate by spectral finite elements. Acta Mech. 223, 2477–2492 (2012)
Roy Mahapatra D., Gopalakrishnan S.: A spectral finite element model for analysis of axial–flexural–shear coupled wave propagation in laminated composite beams. Compos. Struct. 59, 67–88 (2003)
Vinod K.G., Gopalakrishnan S., Ganguli R.: Free vibration and wave propagation analysis of uniform and tapered rotating beams using spectrally formulated finite elements. Int. J. Solids Struct. 44, 5875–5893 (2007)
Lee U., Oh H.: Dynamics of an axially moving viscoelastic beam subject to axial tension. Int. J. Solids Struct. 42, 2381–2398 (2005)
Azizi N., Saadatpour M.M., Mahzoon M.: Using spectral element method for analyzing continuous beams and bridges subjected to a moving load. Appl. Math. Model. 36, 3580–3592 (2012)
Lee U.: Spectral Element Method in Structural Dynamics. Wiley, Singapore (2009)
Ariaei A., Ziaei-Rad S., Ghayour M.: Repair of a cracked Timoshenko beam subjected to a moving mass using piezoelectric patches. Int. J. Mech. Sci. 52, 1074–1091 (2010)
Bathe K.J.: Finite Element Procedures. Prentice-Hall, Englewood Cliffs (1996)
Ariaei A., Ziaei-Rad S., Ghayour M.: Vibration analysis of beams with open and breathing cracks subjected to moving masses. J. Sound Vib. 326, 709–724 (2009)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Sarvestan, V., Mirdamadi, H.R., Ghayour, M. et al. Spectral finite element for vibration analysis of cracked viscoelastic Euler–Bernoulli beam subjected to moving load. Acta Mech 226, 4259–4280 (2015). https://doi.org/10.1007/s00707-015-1491-3
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00707-015-1491-3