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EXAMPLE 7, Slide 3: Part of a model of the truss-core sandwich wall of the cylindrical shell used for the analysis of general buckling

This is Fig. 1b from the 2011 GENOPT paper. This slide shows part of the 46-module model used for the prediction of general buckling of the axially compressed cylindrical shell by GENOPT/BIGBOSOR4.

The truss-core sandwich cross section is discretized, and variation of the general buckling modal displacement in the direction normal to the plane of the paper is trigonometric.

A true prismatic shell model is used for the analysis by BIGBOSOR4.

In this slide the centroid of each "noodle" is indicated by a small green square.

A "noodle" is a tightly rolled up unidirectional ply of composite material. It is rolled up so that the unidirectional fibers are oriented in the axial direction of the "noodle", that is, the "noodle" fibers will be oriented in the axial direction of the truss-core sandwich cylindrical shell wall after the noodle has been inserted into a "noodle gap" in the cross section of the truss-core sandwich wall.

Each tightly rolled up "noodle" is inserted into a "noodle gap". Similar "noodles" are inserted in each "noodle gap" in the cross section of the truss-core sandwich wall of the cylindrical shell.

Noodle gaps are shown in the BIGBOSOR4 prismatic model displayed two slides hence.

In the general buckling model there are no little curved and little flat shell segments that enclose each noodle, as is shown two slides hence in the figure that depicts a single module of one of the local buckling models.

See the next slide for a typical general buckling mode obtained with the type of GENOPT/BIGBOSOR4 model shown here. The segment numbering scheme for each of the 46 general buckling modules is given in the top of Fig. 6 of the 2011 GENOPT paper.

For viewing figures and tables referred to here but not shown here, please download the 2011 GENOPT paper from this website.

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