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ECMS

Source: vignettes/ecms/index.Rmd
index.Rmd

Overview

Unvalidated Experimental
Theory Implementation

These pages sit between the classical elastic-cylinder literature and later finite-length cylinder approximations used in fisheries acoustics (Faran 1951; Stanton 1988).

The elastic cylinder modal series solution (ECMS) is the package’s solid elastic-cylinder family. It combines the phase-shift treatment of an infinite elastic circular cylinder with the usual finite-length coherence factor used near broadside.

Core idea

Represent the elastic interior by longitudinal and transverse cylindrical waves, determine the phase shifts induced by the boundary conditions, and apply the near-broadside finite-length coherence factor to recover monostatic backscatter.

Best for

  • Solid elastic finite cylinders near broadside
  • Backbone-like cylindrical structures where shear-wave support matters
  • Canonical elastic-cylinder benchmarks and component models

Supports

  • ESS or compatible elastic-cylinder scatterers
  • Longitudinal and transverse elastic wave speeds in the cylinder interior
  • Straight and current bent broadside branches

Main assumptions

  • Circular cylinder with homogeneous elastic properties
  • Broadside or near-broadside incidence
  • Finite-length treatment through a coherence factor rather than a fully general 3D elastic solve

Validation status

  • ECMS is currently marked experimental because the documented checks are independent algebra reconstructions rather than an external benchmark or software-comparison ladder.

Family pages

  • Implementation: object setup and current comparison workflow
  • Theory: elastic cylindrical potentials, phase shifts, and finite-length closure

References

Faran, James J. 1951. “Sound Scattering by Solid Cylinders and Spheres.” The Journal of the Acoustical Society of America 23 (4): 405–18. https://doi.org/10.1121/1.1906780.
Stanton, T. K. 1988. “Sound Scattering by Cylinders of Finite Length. I. Fluid Cylinders.” The Journal of the Acoustical Society of America 83 (1): 55–63. https://doi.org/10.1121/1.396184.