FE for Damped Composite Shell Structures
An 8-node specialty damped shear shell finite element was developed for predicting the damping of laminated composite structures of arbitrary laminations and shapes. The FE encompasses a series of mechanics models enabling integrated modeling of damping from ply to structural level. Evaluations of the developed FE with results from other FEs, analytical solutions and conducted experiments have demonstrated its excellent performance, accuracy and unique predictive capabilities.
Related Publication(s): Plagianakos T. S. and Saravanos D. A., "Mechanics and Finite Element for the Damped Dynamic Characteristics of Curvilinear Laminates and Composite Shell Structures", Journal of Sound and Vibration
Composite Damping Characterization
We have developed a unique testing system for measuring Damping Coefficients and Elastic Constants of a composite material from dynamic tests on composite specimens. The system comprises of a series of hardware and software modules enabling dynamic testing of beam specimens, measurement of frequency response functions, extraction of modal values and subsequent extraction of the 3 in-plane damping coefficients and the 4 in-plane elastic coefficients of the composite. There is also capability for characterizing the dependence of damping and elastic coefficients on frequency and temperature.
A novel Composite Bridge was designed and developed through research funding from National Research and Technology Secretariat. Among the many project challenges faced, two were the certification of the developed infrastructure components and the validation of critical design procedures and objectives.
To resolve these issues, a portable modal testing system was developed and set-up for the specific application. A complete dynamic characterization of the bridge was conducted by measuring natural frequencies and dynamic deflection FRFs. Moreover, the system readily enables periodic inspections of the bridge, thus monitoring "structural health signatures" at a fraction of required time and cost.
- Damped Composite Blades
- Passive Vibration Control