Christian Schenk

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Buckling analysis of cylindrical shells with random boundary and geometric imperfections. ABSTRACT: In this paper the individual and combined effects of random boundary and geometric imperfections on the limit loads of isotropic, thin-walled, cylindrical shells under axial compression are presented. Second moment characteristics of these imperfections are(More)
Realistic and efficient reliability estimation for aerospace structures. Abstract In this paper an efficient procedure for calculating non-exceedance probabilities of the structural response is presented, with emphasis on structures modeled by large finite element systems with many uncertain parameters. This is a problem which receives considerable(More)
In this paper the effect of random geometric imperfections on the critical load of isotropic, thin-walled, cylindrical shells under axial compression with rectangular cutouts is presented. Second moment characteristics of geometric imperfections are estimated by data of available measurements, a simulation procedure based on the Karhunen-Lò eve expansion is(More)
A numerical procedure to compute the mean and covariance matrix of the response of nonlinear structures modeled by large FE models is presented. Non-white, non-zero mean, nonstationary Gaussian distributed excitation is represented by the well known Karhunen-Loéve expansion, which allows to describe any type of non-white Gaussian excitation in contrast to(More)
In this paper an efficient procedure for calculating non-exceedance probabilities of large finite element systems with a large number of uncertain parameters is presented, a problem which receives considerably attention in space engineering. For this purpose, a novel sampling procedure is introduced, which allows a significant reduction of the variance of(More)
This paper introduces the CableRobot simulator, which was developed at the Max Planck Institute for Biological Cybernetics in cooperation with the Fraunhofer Institute for Manufacturing Engineering and Automation IPA. The simulator is a completely novel approach to the design of motion simulation platforms in so far as it uses cables and winches for(More)
In this paper we study if approximated linear models are accurate enough to predict the vibrations of a cable of a Cable-Driven Parallel Robot (CDPR) for different pretension levels. In two experiments we investigated the damping of a thick steel cable from the Cablerobot simulator [1] and measured the motion of the cable when a sinusoidal force is applied(More)
In this paper we consider the application problem of a redundant cable-driven parallel robot, tracking a reference trajectory in presence of uncertainties and disturbances. A Super Twisting controller is implemented using a recently proposed gains adaptation law [1], thus not requiring the knowledge of the upper bound of the lumped uncertainties. The(More)
On the analysis of thin shell structures with random imperfections. Abstract. In this paper a stochastic model of random imperfections of cylindrical shells is presented. For this purpose an extensive data bank has been used to estimate second-moment characteristics of these imperfections. The imperfections are then modeled as a two-dimensional ,(More)
Buckling analysis of cylindrical shells with cutouts including random geometric imperfections. Abstract In this paper the effect of random geometric imperfections on the critical load of isotropic, thin-walled, cylindrical shells under axial compression with rectangular cutouts is presented. Second moment characteristics of geometric imperfections are(More)