Abstract
This paper begins with solving the linear elastodynamic equation with forcing by expanding it into Fourier series. We then proceed to prove the conservation laws of momentum, angular momentum, and energy. We intend the paper to provide a computational demonstration for modal analysis by showing that eigenmodes and frequencies of vibration of a free-suspending horse match with the modal analysis results of the horse after a short-impulse impact of the horse with a wall. The horse CAD model has to be modified to contain a rigid body portion to prevent the rotational-tumbling modes. A fast Fourier transform is applied to the sensorial time series data in the calculation of the vibration frequencies. One can see that many low-frequency modes and data match these modal analysis results.
Similar content being viewed by others
References
Chen, G., Huang, J., Wei, C.-Q., Yang, J., Scully, M.M., Sergeev, A., Chen, M.-C., Krantz, S.G., Yao, P.-F., Guo, T., Wang, J.-M.: Animal shapes, modal analysis, and visualization of motion (I): horse and camel. J Geom Anal. (2023). https://doi.org/10.1007/s12220-023-01339-1
Accelerometers: https://en.wikipedia.org/wiki/Accelerometer
Velocimeters/speedometers: https://en.wikipedia.org/wiki/Speedometer
Position sensors: https://en.wikipedia.org/wiki/Position_sensor
Piezoelectric sensors: https://en.wikipedia.org/wiki/Piezoelectric_sensor
Pazy, A.: Semigroups of Linear Operators and Applications to Partial Differential Equations, vol. 44. Springer, Berlin (1983)
Philippe, G.C.: Mathematical Elasticity, vol. I: Three-Dimensional Elasticity. North-Holland, Amsterdam (1988)
Lagnese, J.: Boundary stabilization of linear elastodynamic systems. SIAM J. Control Optim. 21(6), 968–984 (1983)
LSTC: LS-DYNA Keyword User’s Manual, Volume II—Material Models (Version 971 R6.1.0). https://ftp.lstc.com/anonymous/outgoing/jday/manuals/LS-DYNA_manual_Vol_II_R6.1.0.pdf
LSTC: Ansys LS-DYNA Multiphysics solver. https://www.ansys.com/products/structures/ansys-ls-dyna/
Lebeau, G., Schatzman, M.: A wave problem in a half-space with a unilateral constraint at the boundary. J. Differ. Equ. 53(3), 309–361 (1984)
Nowak, M., Sokołowski, J., Żochowski, A.: Biomimetic approach to compliance optimization and multiple load cases. J. Optim. Theory Appl. 184, 210–225 (2020)
Nowak, M., Sokołowski, J., Żochowski, A.: Justification of a certain algorithm for shape optimization in 3d elasticity. Struct. Multidiscip. Optim. 57, 721–734 (2018)
Acknowledgements
We thank Prof. Jan Sokolowski for helpful suggestions. Tiexin Guo is supported by the National Natural Science Foundation of China (No.11671278 and No.11971483) and the Science and Technology Research Project of Chongqing Municipal Education Commission(KJ1706154). Pengfei Yao is supported in part by the National Science Foundation of China, grant No. 12071463, and by the special fund for Science and Technology Innovation Teams of Shanxi Province, Grants # 202204051002015. Junmin Wang is supported in part by the National Natural Science Foundation of China No. 62073037 and 12131008. Chunqiu Wei is supported by the Research Ability Improvement Program for Young Teachers of BUCEA (Grant No. X21031).
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
G. Chen—on Development Leave from Texas A &M University.
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
About this article
Cite this article
Chen, G., Wei, C., Sergeev, A. et al. Animal Shapes, Modal Analysis, and Visualization of Motion (II): Dynamics and Fourier Decomposition. J Geom Anal 33, 309 (2023). https://doi.org/10.1007/s12220-023-01342-6
Received:
Accepted:
Published:
DOI: https://doi.org/10.1007/s12220-023-01342-6