Showing papers by "Rüdiger Schmidt published in 2019"

A review on modeling techniques of piezoelectric integrated plates and shells

Abstract: Piezoelectric materials embedded into plates and shells make the structures being capable of sensing and actuation, usually called smart structures, which are frequently used for shape and vibratio...

Nonlinear finite element modeling of vibration control of plane rod-type structural members with integrated piezoelectric patches

Abstract: This paper addresses modeling and finite element analysis of the transient large-amplitude vibration response of thin rod-type structures (e.g., plane curved beams, arches, ring shells) and its control by integrated piezoelectric layers. A geometrically nonlinear finite beam element for the analysis of piezolaminated structures is developed that is based on the Bernoulli hypothesis and the assumptions of small strains and finite rotations of the normal. The finite element model can be applied to static, stability, and transient analysis of smart structures consisting of a master structure and integrated piezoelectric actuator layers or patches attached to the upper and lower surfaces. Two problems are studied extensively: (i) FE analyses of a clamped semicircular ring shell that has been used as a benchmark problem for linear vibration control in several recent papers are critically reviewed and extended to account for the effects of structural nonlinearity and (ii) a smart circular arch subjected to a hydrostatic pressure load is investigated statically and dynamically in order to study the shift of bifurcation and limit points, eigenfrequencies, and eigenvectors, as well as vibration control for loading conditions which may lead to dynamic loss of stability.

Numerical static and dynamic analyses of improved equivalent models for corrugated sandwich structures

Abstract: In order to further improve the accuracy of the equivalent models of the trapezoidal corrugated core, a 3D homogenization method based on a representative unit cell (RUC) has been developed...

Disturbance rejection control with H∞ optimized observer for vibration suppression of piezoelectric smart structures

Abstract: In this paper, a disturbance rejection (DR) control with H ∞ optimized observer is developed for vibration suppression of smart structures considering model uncertainties and measurement noise. An electro-mechanically coupled dynamic finite element (FE) model of piezoelectric smart structures is firstly built for control design. Based on the dynamic FE model, the H ∞ optimized observer is designed with a dynamic feedback gain which is calculated by H ∞ mixed sensitivity optimization. Expected response speed and robustness to model uncertainties and measurement noise are obtained by configuring proper weighting functions. In the closed-loop system, estimated disturbances and state variables are fed back through a conventional DR controller to counteract disturbances and stabilize the system. In order to validate the DR control with H ∞ optimized observer, vibration suppression simulations of a piezoelectric smart beam are implemented in the absence and presence of model uncertainties and measurement noise, respectively. Furthermore, DR control with generalized proportional integral observer and DR control with high-gain proportional integral observer are added for comparison. Results show that excellent vibration suppression performance and better robustness to model uncertainties and measurement noise are achieved by the DR control with H ∞ optimized observer.