On Dynamics of Rigid Sphere-reinforced Metacomposite Beams and Rods

• Author / Creator

  Meng, Jiacen

• An analytical model is presented to study dynamic behaviors of rigid sphere-reinforced random metacomposites. The model is based on the concept that the deviation of the displacement field of embedded rigid spheres from the displacement field of the composite is responsible for novel dynamic behaviors of stiff sphere-reinforced metacomposites. Compared to the existing models, the present model offers a simple general method to analyze dynamic problems of rigid sphere-reinforced random metacomposites, and its validity and efficiency are demonstrated by comparing the predicted results for bandgap with known experimental or numerical data on several typical steel/glass/lead-polymer metacomposites. Several basic dynamic problems of rigid sphere-reinforced metacomposite beams and rods are investigated, and some novel dynamic phenomena (such as vibration isolation, localized buckling, and natural frequency within the bandgap caused by an attached concentrated mass) are demonstrated. The main results include: 1). natural frequencies of a rigid sphere-reinforced metacomposite beam or rod always stay outside of the bandgap, independent of all other material and geometrical parameters, while a concentrated mass attached to the free end of a rod may cause a natural frequency within the bandgap. 2). a rigid sphere-reinforced metacomposite beam or rod can exhibit vibration isolation phenomena so that the forced vibration is highly localized near the site of the applied external periodic excitation and vanishing small in all other parts of the beam or rod when the external excitation frequency falls within the bandgap, while the forced vibration does spread into the entire beam or rod when the excitation frequency is out of the bandgap. 3). a hinged rigid sphere-reinforced metacomposite beam under a constant compressive load can exhibit localized buckling at the critical buckling state when the mass ratio of the rigid-sphere phase to the matrix phase is vanishingly small.

• Subjects / Keywords

  • metacomposite
  • locally resonant
  • rigid sphere
  • dynamic
  • effective mass density
  • bandgap
  • vibration isolation
  • random

• Graduation date

  Fall 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-c44d-as83

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.