FINITE ELEMENT FORMULATION AND ACTIVE VIBRATION CONTROL STUDY ON BEAMS USING SMART CONSTRAINED LAYER DAMPING (SCLD) TREATMENT
✍ Scribed by V. BALAMURUGAN; S. NARAYANAN
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 471 KB
- Volume
- 249
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
This work deals with the active vibration control of beams with smart constrained layer damping (SCLD) treatment. SCLD design consists of viscoelastic shear layer sandwiched between two layers of piezoelectric sensors and actuator. This composite SCLD when bonded to a vibrating structure acts as a smart treatment. The sensor piezoelectric layer measures the vibration response of the structure and a feedback controller is provided which regulates the axial deformation of the piezoelectric actuator (constraining layer), thereby providing adjustable and signi"cant damping in the structure. The damping o!ered by SCLD treatment has two components, active action and passive action. The active action is transmitted from the piezoelectric actuator to the host structure through the viscoelastic layer. The passive action is through the shear deformation in the viscoelastic layer. The active action apart from providing direct active control also adjusts the passive action by regulating the shear deformation in the structure. The passive damping component of this design eliminates spillover, reduces power consumption, improves robustness and reliability of the system, and reduces vibration response at high-frequency ranges where active damping is di$cult to implement. A beam "nite element model has been developed based on Timoshenko's beam theory with partially covered SCLD. The Golla}Hughes}McTavish (GHM) method has been used to model the viscoelastic layer. The dissipation co-ordinates, de"ned using GHM approach, describe the frequency-dependent viscoelastic material properties. Models of PCLD and purely active systems could be obtained as a special case of SCLD. Using linear quadratic regulator (LQR) optimal control, the e!ects of the SCLD on vibration suppression performance and control e!ort requirements are investigated. The e!ects of the viscoelastic layer thickness and material properties on the vibration control performance are investigated.