Semi-Analytical Finite Element Modeling

Attenuation dispersion curves, energy velocity dispersion curves, and strain cross-sectional mode shapes at 200 kHz for [0/±45/0]S CFRP panel bonded to CFRP woven spar
Mode shapes of flexural waves in railroad tracks at 150 kHz
Phase velocity dispersion curves, group velocity dispersion curves and strain energy cross-sectional mode shapes in railroad track at high frequency
High-frequency mode shapes of railroad track
Phase velocity dispersion curves and cross-sectional mode shapes for 0.6-in seven-wire steel strand
Phase velocity dispersion curves, group velocity dispersion curves and displacement cross-sectional mode shapes for [0/±45/90]S T800/924 CFRP laminate
Forced solution for [0/±45/0]S T800/924 CFRP panel- broadband excitation (with and without delamination defect)
Forced solution for 5mm-dia. steel rod - broadband excitation

Funding:

  • National Science Foundation
  • Department of Transportation/Federal Railroad Administration
  • Air Force Office of Scientific Research
  • Office of Naval Research

Collaborators:

  • Prof. Alessandro Marzani, University of Bologna

Purpose:

To develop a computational tool to predict guided wave propagation in waveguides of arbitrary cross-sections, including multilayers.

Synopsis:

We are using extensively Semi-Analytical Finite Element (SAFE) models to predict dispersive wave solutions in waveguides. SAFE only requires the discretization of the cross-section of the waveguide, thereby greatly improving the computational efficiency compared to conventional 3-D FEA. Moreover, SAFE solves an eigenvalue problem with a numerically stable solution. Our SAFE code can extract phase/group velocity curves, cross-sectional mode shapes, and response time histories, in both unforced and forced cases. The code can also account for multilayered geometries and anisotropic viscoelastic materials (e.g. composites).

SAFE is the primary guided wave modeling tool used at UCSD to study the dynamics of cables, pipes, aerospace panels, adhesive joints and rail tracks for NDE and SHM purposes. The SAFE code is also being used in an inverse manner to determine the magnitude of unknown impact forces on aerospace panels.

A user-friendly interface is currently being added to our SAFE code in collaboration with the University of Bologna.

Selected publications:

Nucera, C. and Lanza di Scalea, F., “Modeling of Nonlinear Guided Waves and Applications To Structural Health Monitoring,” ASCE Journal of Computing in Civil Engineering, Special Issue on Computing, SangHyun Lee, Burcin Becerik-Gerber, and Ioannis Brilakis, eds., in press, 2014. (invited paper)

Nucera, C. and Lanza di Scalea, F., “Nonlinear Semi-Analytical Finite Element Algorithm for the Analysis of Internal Resonance Conditions In Complex Waveguides,” ASCE Journal of Engineering Mechanics, 140(3), pp. 502-522, 2014.

Nucera, C. and Lanza di Scalea, F., “Modeling of Nonlinear Guided Waves And Applications To Structural Health Monitoring,” Computing in Civil Engineering, Proceedings of the 2013 ASCE International Workshop on Computing in Civil Engineering (IWCCE), University of Southern California, Los Angeles, pp. 105-112, June 23-25, 2013.

Nucera, C. and Lanza di Scalea, F., “Higher Harmonic Generation Analysis in Complex Waveguides via a Nonlinear Semi-Analytical Finite Element Algorithm,” Mathematical Problems in Engineering, Special Issue on New Strategies and Challenges in SHM for Aerospace and Civil Structures, Hindawi Publishing Corporation, vol. 2012, doi:10.1155/2012/365630, 16 pgs., 2012.

Bartoli, I., Salamone, S., Phillips, R., Lanza di Scalea, F. and Sikorsky, C., “Use of Interwire Ultrasonic Leakage to Quantify Loss of Prestress in Multiwire Tendons,” ASCE Journal of Engineering Mechanics, 137(5), pp. 324-333, 2011.

Coccia, S., Bartoli, I., Marzani, A., Lanza di Scalea, F., Salamone, S. and Fateh, M., “Numerical and Experimental Study of Guided Waves for Detection of Rail Head Defects,” NDT&E International, 44(1), pp. 93-100, 2011.

Srivastava, A., Bartoli, I., Salamone, S. and Lanza di Scalea, F., “Higher Harmonic Generation in Nonlinear Waveguides of Arbitrary Cross-section,” Journal of the Acoustical Society of America, Vol. 127(5), pp. 2790-2796, 2010.

Srivastava, A. and Lanza di Scalea, F., “Quantitative Structural Health Monitoring by Ultrasonic Guided Waves,” ASCE Journal of Engineering Mechanics, 136(8), pp. 937-944, 2010.

Srivastava, A. and Lanza di Scalea, F., “Quantitative Structural Health Monitoring by Ultrasonic Guided Waves,” International Journal of Condition Monitoring and Diagnostic Engineering Management (COMADEM), Special Issue on Structural Health Monitoring, 13(1), pp. 26-33, 2010 (invited).

Bartoli, I., Salamone, S., Phillips, R., Lanza di Scalea, F., Coccia, S., and Sikorsky, C., “Monitoring Prestress Level in Seven-wire Prestressing Tendons by Inter-wire Ultrasonic Wave Propagation,” Journal of Advances in Science and Technology – Embodying Intelligence in Structures and Integrated Systems, 56, pp. 200-205, 2008.

Marzani, A., Viola, E., Bartoli, I., Lanza di Scalea, F., and Rizzo, P., “A Semi-analytical Finite Element Formulation for Modeling Stress Wave Propagation in Axisymmetric Damped Waveguides,” Journal of Sound and Vibration, Vol. 318(3), pp. 488-505, 2008.

Bartoli, I., Marzani, A., Lanza di Scalea, F., and Viola, E., “Modeling Wave Propagation in Damped Waveguides of Arbitrary Cross-section,” Journal of Sound and Vibration, Vol. 295(3-5), pp. 685-707, 2006.