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On wave equations for elastic rods. (English) Zbl 0958.74029

Summary: We derive one-dimensional wave equations for axially symmetric waves in elastic rods. By using series expansions in the radial coordinate, we obtain a hierarchy of wave equations. As the lowest reasonable approximation, the usual simple wave equation for the rod is recovered. At the next level, we derive a fourth-order wave equation. The dispersion relation and displacements for these approximations and for Love’s equation are compared with the lowest branch of the exact Pochhammer-Chree equation. We also consider an excitation problem with a shear force, and compare the results with other theories.

MSC:

74J05 Linear waves in solid mechanics
74K10 Rods (beams, columns, shafts, arches, rings, etc.)
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