Biaxial strength testing also has some disadvantages compared with uniaxial testing. First, friction between the T here is widespread use of biaxial testing of ceramics, test piece and the loading and support parts of the test jig but relatively little information concerning the accuracy has been widely recognised in uniaxial flexural testing, of testing, and the pitfalls that can arise unless the test and has been eliminated in recently standardised tests is carefully prescribed. T he present paper reviews (CEN EN 843-1, ASTM C1161) by requiring the use of recent work in measuring elastic moduli using a biaxial freely rolling contact rollers. In biaxial testing, friction natural f requency method, and in investigating some of is usually ignored in the analysis, but will clearly play the potential sources of error in strength testing.a similar if not larger role in biaxial testing. There is BCT /335 no simple equivalent to rolling rollers, and the nearest equivalent is to use freely rolling balls captive in a ring.

The anisoparametric three-node MIN6 shallow shell element is extended for modeling Macro-Fiber Composite/Active Fiber Composites (MFCTM/AFC) actuators for active vibration and acoustic control of curved and flat panels. The recently developed MFCTM/AFC actuators exhibit enhanced performance, they are anisotropic and highly conformable as compared to the traditional monolithic isotropic piezoceramic actuators. The extended MIN6 shell element includes embedded or surface bonded MFCTM/AFC laminae. The fully coupled electrical-structural formulation is general and it is able to handle arbitrary doubly curved laminated composite and isotropic shell structures. A square and a triangular cantilever isotropic plates are modeled using the MIN6 elements to demonstrate the anisotropic actuation of a surface bonded MFCTM actuator for coupled bending and twisting plate motions. Steady state modal bending and twisting amplitudes of the cantilever square and triangular plates with MFCTM actuator are compared with the plate’s steady state modal amplitudes with traditional PZT 5A actuator for different angle orientations. Frequency Response Functions (FRF) for the square plate with MFCTM and PZT 5A actuators are also obtained and their actuation performance is compared. The actuation performance of the MFCTM at different locations is also investigated.

Piezoceramic actuator placement is investigated to minimize structurally radiated noise of flat and curved panels subjected to a uniform random acoustic disturbance. The flat panels use traditional PZT actuators, while the curved panels incorporate anisotropic macro fiber composite (MFC) PZT actuators. A linear quadratic regulator (LQR) feedback control augmented with acoustic radiation filters is used to minimize the radiated noise. A coupled finite element model is used in conjunction with a genetic algorithm to determine the optimum actuator location for two PZT actuators. Experiments are conducted to verify analytical simulation results.

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