Textile composites made of woven fabrics have demonstrated excellent mechanical properties for the production of high specific-strength products. Research efforts in the woven fabric sheet forming are currently at a point where benchmarking will lead to major advances in understanding both the strengths and the limitations of existing experimental and modeling approaches. Test results can provide valuable information for the material characterization and forming process design of woven composites if researchers know how to interpret the results obtained from varying test methods appropriately. An international group of academic and industry researchers has gathered to design and conduct benchmarking tests of interest to the composite sheet forming community. Shear deformation is the dominative deformation mode for woven fabrics in forming; therefore, trellis-frame (picture-frame) and biasextension tests for both balanced and unbalanced fabrics have been conducted and compared through this collaborative effort. Tests were conducted by seven international research institutions on three identical woven fabrics. Both the variations in the setup of each research laboratory and the normalization methods used to compare the test results are presented and discussed. With an understanding of the effects of testing variations on the results and the normalization methods, numerical modeling efforts can commence and new testing methods can be developed to advance the field.

No abstract

A finite-element model based on the classical laminated plate theory is developed for the active vibration control of a composite plate containing distributed piezoelectric sensors and actuators. The formulation is derived from the variational principle. The piezoelectrics' mass and stiffness are taken into account in the present model. A simple negative velocity feedback control algorithm coupling the direct and converse piezoelectric effects is used to actively control the dynamic response of an integrated structure through a closed control loop. The static analysis and active vibration suppression of a cantilever composite plate are performed as a numerical example to verify the proposed model. The modal superposition technique and the Newmark-β method are used in the numerical simulation to calculate the dynamic response of the laminated composite plate.

No abstract

No abstract