Effective Shear Deformable Shell Elements for Adaptive Laminated Structures

An effective mixed interpolation approach for shell elements is here extended to the analysis of adaptive shells consisting of a sequence of active and passive layers. An active layer – made by a piezoelectric material or a similar active medium – is assumed to be included in the stacking sequence of a laminated shell. The actuation capability of the layer is represented by a given inplane strain field that can be thought of as being produced by the converse piezoelectric effect or other induced strain actuation mechanism. In this way, the actuation mechanism is included in the formulation of shear deformable shell element that has been demonstrated not to suffer of shear locking effects. A four node element was developed. Several comparisons have been performed to verify the accuracy of the formulation and to check the predicting capability of the element in comparison with both numerical and experimental results of the recent available literature. Also an application to a real composite structure is illustrated in order to demonstrate the possible use of the proposed element in the engineering practice.