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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. |
Testing configuration of composite beam specimen for extraction of damping and elastic coefficients |
Extracted Elastic Parameters (longitudinal, transverse, shear moduli and Poisson's ratio) yield perfect fitting with measured axial modulus values of the composite specimen |
Likewise, extracted composite damping coefficients (longitudinal, transverse, shear loss factors) yield perfect fitting with measured axial damping of the composite specimen |
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1. Measurement of Damped Dynamic Characteristics of Composite Panels: |
| Dynamic testing of Glass/Polyester cylindrical panel. |
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| Experimental configuration for measurement of Modal Frequencies, Modal Damping and Mode Shapes. |
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| Measured natural frequencies and modal loss factors of a Glass/Polyester cylindrical panel perfectly match analytically predicted values using our newly developed damped shell element. Numbers in parenthesis indicate predicted mode number. |
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| 2. Dynamic Testing of Large-Scale Structures: |
On Site Modal Testing of a Novel Composite Highway Overpass Bridge.
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. |
| Preparation for on-site Dynamic Testing of Composite Bridge. |
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| Impact Force Excitation and Response Measurement at Specific Bridge Location(s). |
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