Register now After registration you will be able to apply for this opportunity online.
This opportunity is not published. No applications will be accepted.
Concept for Experimental Validation of Corrugated Laminates Structural Transverse Stiffness
A newly developd planar finite element model can efficiently calculate substitute-plate trasnverse stiffness values. It is very difficult to validate the results with static experiments, wherefore eigenfrequency measurement of laminates is preferable.The work searches for the right configurations.
High-amplitude vorrugated laminates possess much higher bending than transverse-shear stiffness, where the ratio between the two may be much higher than in sandwich plates. As of yet, no previous model for calculating transverse shear stiffness for corrugated laminates exists. We are currently developing a numerically efficient planar finite-element formulation for the problem and need a concept for experimental validation of it. We are thinking of measuring and interpreting the influence of transverse shear compliance on the Eigen-frequency spec-trum as a means for model validation; however, corrugated laminates with high corrugation amplitude exhibit non-classical vibration modes which must be taken into account. The chal-lenge lies in the selection of geometric parameters to excite the very modes whose Eigen frequencies depend on transverse-shear compliance.
High-amplitude vorrugated laminates possess much higher bending than transverse-shear stiffness, where the ratio between the two may be much higher than in sandwich plates. As of yet, no previous model for calculating transverse shear stiffness for corrugated laminates exists. We are currently developing a numerically efficient planar finite-element formulation for the problem and need a concept for experimental validation of it. We are thinking of measuring and interpreting the influence of transverse shear compliance on the Eigen-frequency spec-trum as a means for model validation; however, corrugated laminates with high corrugation amplitude exhibit non-classical vibration modes which must be taken into account. The chal-lenge lies in the selection of geometric parameters to excite the very modes whose Eigen frequencies depend on transverse-shear compliance.
The possibilities of using the Eigen-frequency spectrum for obtaining structural transverse-shear stiffness values of corrugated plates shall be explored by numerical simulation of ex-perimental test situations. Because of the existence of non-classical vibration modes, a de-tailed geometry mapping of the corrugated laminates by use of general-purpose FEM soft-ware will be necessary. The vibration behavior will be influenced by the corrugation shape, plate dimensions, and laminate design. The desired outcome of the parameter study is the specification of suitable test specimens and boundary conditions which would function over a desired frequency spectrum as to identify structural transverse shear stiffness values.
The possibilities of using the Eigen-frequency spectrum for obtaining structural transverse-shear stiffness values of corrugated plates shall be explored by numerical simulation of ex-perimental test situations. Because of the existence of non-classical vibration modes, a de-tailed geometry mapping of the corrugated laminates by use of general-purpose FEM soft-ware will be necessary. The vibration behavior will be influenced by the corrugation shape, plate dimensions, and laminate design. The desired outcome of the parameter study is the specification of suitable test specimens and boundary conditions which would function over a desired frequency spectrum as to identify structural transverse shear stiffness values.
Daniel Filipovic & Gerald Kress
ETH Z CLA E 32.2 / E 31
Tannenstrasse 3
CH 8092 Zürich
fidaniel@ethz.ch & gkress@ethz.ch
Daniel Filipovic & Gerald Kress ETH Z CLA E 32.2 / E 31 Tannenstrasse 3 CH 8092 Zürich fidaniel@ethz.ch & gkress@ethz.ch
Prof. W. Becker TU Darmstadt Franziska-Braun-Straße 7 64287 Darmstadt becker@fsm.tu-darmstadt.de