Papers by Rüdiger Schmidt
“Static resonance” in cylindrical shells with periodical initial imperfections under external pressure
Shell Structures: Theory and Application, 2013
On a moderate rotation theory of laminated anisotropic shells—Part 1. Theory
International Journal of Non-Linear Mechanics, 1990
ABSTRACT A moderate rotation theory of laminated anisotropic shells, proposed by Schmidt and Redd... more ABSTRACT A moderate rotation theory of laminated anisotropic shells, proposed by Schmidt and Reddy [J. appl. Mech. 55, 611–617.1988], is developed and its application is presented. All aspects of the derivations are explicitly developed and specific forms of the equations are derived in this part. The finite-element formulation and its applications are presented in Part 2 of the paper.
Deformation and buckling of axially compressed cylindrical shells with local loads in numerical simulation and experiments
Thin-Walled Structures, 2011
ABSTRACT By means of geometrically non-linear modeling of the test process for high-quality speci... more ABSTRACT By means of geometrically non-linear modeling of the test process for high-quality specimens of thin-walled cylinders using a shell finite element implemented in ANSYS, it has been proved that this numerical approach is applicable for design of real axially compressed circular cylindrical shells under external local quasi-static loads.
A Refined Small Strain and Moderate Rotation Theory of Elastic Anisotropic Shells
Journal of Applied Mechanics, 1988
A general refined shell theory that accounts for the transverse deformation, small strains, and m... more A general refined shell theory that accounts for the transverse deformation, small strains, and moderate rotations is presented. The theory can be reduced to various existing shell theories including: the classical (i.e., linear Kirchhoff-Love) shell theory, the Donnell-Mushtari-Vlasov shell theory, the Leonard-Koiter-Sanders moderate rotations shell theory, the von Ka´rma´n type shear-deformation shell theory and the moderate-rotation shear-deformation plate theory developed by Reddy. The present theory is developed from an assumed displacement field, nonlinear strain-displacement equations that contain small strain and moderate rotation terms, and the principle of virtual displacements. The governing equations exhibit strong coupling between the membrane and bending deformations, which should alter the bending, stability, and post-buckling behavior of certain shell structures predicted using the presently available theories.
Thin elastic shells undergoing small strain and large rotations. - A simple consistent theory and variational principles
In the present paper the deflections of viscoplastic plates subjected to repeated impulsive surfa... more In the present paper the deflections of viscoplastic plates subjected to repeated impulsive surface loads are studied and compared with those of quasistatically loaded structures. Experiments are carried out in a shock tube on clamped circular steel and copper plates. Parallely, numerical simulations are performed by Finite-Element analysis based on a geometrically nonlinear shell theory. Two different possibilities for the plate response to repeated dynamic loads are considered. In one case the permanent deflections exceed, in the other case they tend towards the quasi-static deflections.
Geometrically Nonlinear FE Analysis of Composite Laminated Cylindrical Shells
Anisotropic Damage Evolution and Failure of Dynamically Loaded Thin-Walled Structures: Modelling, Finite Element Simulation and Experimental Study
Proceedings of the Eleventh International Conference on Civil, Structural and Environmental Engineering Computing
Mechanics Research Communications, 1984
j(3)(u ;Uc ..) + i (4)(Uc ;. .. c 2Vc 7 O Vc~) + Ac[d(3)(Uc;U<>V. v.) + d(4)(a ;uOu 3) ]
Journal of Vibration and Control, 2017
Flexible structures have been increasingly utilized in many applications because of their light-w... more Flexible structures have been increasingly utilized in many applications because of their light-weight and low production cost. However, being flexible leads to vibration problems. Vibration suppression of flexible structures is a challenging control problem because the structures are actually infinite-dimensional systems. In this paper, an adaptive control scheme is proposed for the vibration suppression of a piezo-actuated flexible beam. The controller makes use of the configuration of the prominent proportional-integral-derivative controller and is derived using an infinite-dimensional Lyapunov method. In contrast to existing schemes, the present scheme does not require any approximated finite-dimensional model of the beam. Thus, the stability of the closed loop system is guaranteed for all vibration modes. Experimental results have illustrated the feasibility of the proposed control scheme.
Higher-Order Moderate Rotation Theories for Elastic Anisotropic Plates
Lecture Notes in Engineering, 1986
A great deal of interest in the substantiation of refined theories of elastic an-isotropic plates... more A great deal of interest in the substantiation of refined theories of elastic an-isotropic plates and shells has been manifested in the specialized literature in the last two decades. This interest is largely due to the need for more adequate methods of analysis of structural elements exposed to severe and complex operational conditions in various branches of the advanced technology. In addition, the increased use of new exotic composite materials has provided a new impetus for such refined theories. As it was conclusively shown, the classical methods of analysis based on the Kirchhoff-Love assumptions are inadequate in many important instances. This is especially true whenever the material of the structure exhibits high degrees of anisotropy in its physical and mechanical properties. Such features are typical for the composite and refractory type materials used with increased frequency in the aerospace, naval, nuclear industries, etc. In such cases, refined models allowing a more adequate description of the structural response are needed. They should include transverse shear and transverse normal deformations and should account for the higher-order effects.
Geometrically Nonlinear FE Instability Simulations of Hinged Composite Laminated Cylindrical Shells
A large rotation shell theory with six independent parameters considering arbitrary rotations is ... more A large rotation shell theory with six independent parameters considering arbitrary rotations is implemented for buckling and post-buckling analysis of panels based on first-order shear deformation (FOSD) hypothesis. The results obtained by the proposed large rotation theory are compared with those by moderate rotation theory.
Computational Simulation of the Transient Elastic-Viscoplastic Response of Structural Components at High Temperature
Variationsprinzipe für geometrisch Nichtlineare Schalentheorien bei rotationen mittlerer Grössenordnung /
Thesis (doctoral)--Ruhr-Universität Bochum, 1980.
Variational Principles for General and Restricted Geometrically Non-Linear Kirchhoff-Love Type Shell Theories
Finite Element Simulation of Damage Evolution in Dynamically Loaded Structures
Thin Elastic Shells Undergoing Small Strains and Large Rotations - A Simple Consistent Theory and Associated Variational Principles
A Geometrically Nonlinear Finite Element for Transient Analysis of Piezolaminated Shells
On Nonlinear Thermo-Electro-Elasticity Theory and Finite Element Analysis of Piezolaminated Thin-Walled Structures
Geometrically nonlinear theory of laminated anisotropic composite plates featuring interlayer slips
A geometrically nonlinear theory of laminated composite anisotropic plates featuring nonrigidly b... more A geometrically nonlinear theory of laminated composite anisotropic plates featuring nonrigidly bonded interfaces is presented. The theory incorporates transverse shear effects and fulfills the static continuity conditions of tangential tractions at the layer interfaces. The effect of an arbitrary temperature field is also incorporated. The pertinent equations of equilibrium/motion are derived by means of Hamilton’s variational principle which also supplies the boundary conditions. For completeness, the paper concludes with some remarks on several general theorems which are counterparts of the three-dimensional elasticity theory.
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Papers by Rüdiger Schmidt