Abstract
In this chapter, wave propagation in a thin rod struck by a rigid mass is considered and a finite element simulation of the system is developed. Both cases of free–free and fixed-free rods are considered. Though impact generates a propagating stress wave in both cases, the free–free rod is going to have a rigid-body motion. The analytical equations of motion are presented and the corresponding finite element equations are derived. A numerical scheme is constructed and solutions are obtained using Newmark implicit integration method and Newton–Raphson iterative technique. Solutions include time histories of displacement, velocity, stress, and contact force. The contact force is calculated, according to St. Venant’s impact model. Numerical results of the simulation are compared to traditional analytical results. A simulated visualization of the propagation of the stress wave in the rod is presented, which enhances the understanding of this complicated physical phenomenon. The achieved results are accurate enough to have confidence in using this model for practical applications in wave propagation simulation and analysis.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Abbreviations
- A :
-
Cross-sectional area (m2)
- c :
-
Wave propagation velocity (m/s)
- E :
-
Young’s modulus (N/m2)
- F :
-
Contact force (N)
- \( \{ f\} \) :
-
Global force vector (N)
- \( \{ f\}_{el} \) :
-
Force vector for element in contact with the rigid mass (N)
- \( \left[ K \right] \) :
-
Global stiffness matrix (N/m)
- l :
-
Length (m)
- L :
-
Lagrangean (J)
- m :
-
Mass of the rod (kg)
- \( m_{0} \) :
-
Mass of the rigid mass (kg)
- \( \left[ M \right] \) :
-
Global mass matrix (kg)
- \( \left[ N \right] \) :
-
Finite element shape functions (m/m)
- q :
-
Displacement of the rigid mass (m)
- \( \dot{q} \) :
-
Velocity of the rigid mass (m/s)
- t :
-
Time (s)
- \( t_{c} \) :
-
Contact period (s)
- T :
-
Kinetic energy (J)
- u :
-
Displacement of the rod at position x(m)
- \( \{ U\} \) :
-
Nodal displacement vector (m)
- \( \{ \dot{U}\} \) :
-
Velocity vector (m/s)
- \( \{ \mathop U\limits^{..} \} \) :
-
Acceleration vector (m/s2)
- \( \left\{ U \right\}_{el} \) :
-
Nodal displacement vector element in contact with the rigid mass (m)
- \( U_{s} \) :
-
Strain energy (J)
- \( \upsilon_{0} \) :
-
Initial velocity of the rigid mass (m/s)
- W :
-
Work done (J)
- x :
-
Position in the rod (m)
- ε:
-
Strain in the rod (m/m)
- Π :
-
Potential energy (J)
- ρ :
-
Density (kg/m3)
- σ :
-
Stress in the rod (N/m2)
- τ:
-
Time for the wave to travel across the rod from one end to the other end (s)
- \( \left( {} \right)_{N} \) :
-
Value at the previous time step (N = 0,1,2,…)
- \( \left( {} \right)_{N + 1} \) :
-
Value at the current time step (N = 0,1,2,…)
References
Goldsmith, W.: Impact: The Theory and Physical Behaviour of Colliding Solids. Edward Arnold, Ltd, London (1960)
Timoshenko, S.P., Goodier, J.N.: Theory of Elasticity. McGraw Hill, New York (1970)
Shi, P.: Simulation of impact involving an elastic rod. Comput. Met. Appl. Mech. Eng. 151, 497–499 (1997)
Hu, B., Eberhard, P.: Symbolic computation of longitudinal impact waves. Comput. Met. Appl. Mech. Eng. 190, 4805–4815 (2001)
Hu, B., Eberhard, P.: Simulation of longitudinal impact waves using time delayed systems. J. Dyn. Syst., Meas. Control (Special Issue) 126(3), 644–649 (2004)
Keskinen, E., Kuokkala, V.-T., Vuoristo, T., Martikainen, M.: “Multi-body wave analysis of axially elastic rod systems,” Proc. Instn. Mech. Engrs, Part K. J. Multi-body Dyn. 221, 417–428 (2007)
Maekawa, I., Tanabe, Y., Suzuki, M.: Impact stress in a finite rod. JSME Int. J. Ser. I 31, 554–560 (1988)
Hu, B., Schiehlen, W., Eberhard, P.: Comparison of analytical and experimental results for longitudinal impacts elastic rods. J. Vib. Control 9, 157–174 (2003)
Al-Mousawi, M.M.: On experimental studies of longitudinal and flexural wave propagations: an annotated bibliography. Appl. Mech. Rev 39, 853–864 (1986)
Ueda, K., Umeda, A.: Characterization of shock accelerometers using Davies bar and strain-gages. Exp. Mech. 33(3), 228–233 (1993)
Rusovici, R.: “Modeling of shock wave propagation and attenuation in viscoelastic structure,” Ph.D. Dissertation, Virginia polytechnic institute and state university (1999)
Ramirez, H., Rubio-Gonzalez, C.: Finite-element simulation of wave propagation and dispersion in Hopkinson bar test. Mater. Des. 27, 36–44 (2006)
Allen, D.J., Rule, W.K., Jones, S.E.: Optimizing material strength constants numerically extracted from Taylor impact data. Exp. Mech. 37(3), 333–338 (1997)
El-Saeid Essa, Y., Lopez-Puente, J., Perez-Castellanos, J.L.: Numerical simulation and experimental study of a mechanism for Hopkinson bar test interruption. J. Strain Anal. Eng. Des. 42(3), 163–172 (2007)
Seifried, R., Schiehlen, W., Eberhard, P.: Numerical and experimental evaluation of the coefficient of restitution for repeated impacts. Int. J. Impact Eng. 32(1–4), 508–534 (2005)
Seifried, R., Eberhard, P.: Comparison of numerical and experimental results for impacts. ENOC-2005, pp. 399–408. Eindhoven, Netherlands, (2005) 7–12 August
Krawczuk, M.: Application of spectral beam finite element with crack and iterative search technique for damage detection. Finite Elements Anal. Des. 38(6), 537–548 (2002)
Krawczuk, M., Palacz, M., Ostachowicz, W.: Wave propagation in plate structures for crack detection. Finite Elements Anal. Des. 40(9–10), 991–1004 (2004)
Bathe, K.-J.: Finite Element Procedures. Prentice Hall, Upper Saddle River (1996)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2012 Springer-Verlag Berlin Heidelberg
About this chapter
Cite this chapter
Elkaranshawy, H.A., Bajaba, N.S. (2012). A Finite Element Simulation of Longitudinal Impact Waves in Elastic Rods. In: Öchsner, A., da Silva, L., Altenbach, H. (eds) Materials with Complex Behaviour II. Advanced Structured Materials, vol 16. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-22700-4_1
Download citation
DOI: https://doi.org/10.1007/978-3-642-22700-4_1
Published:
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-22699-1
Online ISBN: 978-3-642-22700-4
eBook Packages: Chemistry and Materials ScienceChemistry and Material Science (R0)