Towards a general statistical theory of imperfection-sensitivity in elastic post-buckling

1967 ◽  
Vol 15 (6) ◽  
pp. 413-417 ◽  
Author(s):  
J.M.T. Thompson
Keyword(s):  
Statistical Theory ◽  
Imperfection Sensitivity ◽  
Post Buckling ◽  
General Statistical

Post-buckling Behavior of Stiffened Cross-Ply Cylindrical Shells

1994 ◽  
Vol 61 (4) ◽  
pp. 998-1000 ◽  
Author(s):  
M. Savoia ◽  
J. N. Reddy
Keyword(s):  
Axial Compression ◽  
Carrying Capacity ◽  
Shell Theory ◽  
Load Carrying Capacity ◽  
Imperfection Sensitivity ◽  
Buckling Modes ◽  
Geometric Imperfection ◽  
Buckling Behavior ◽  
Load Carrying ◽  
Post Buckling

The post-buckling of stiffened, cross-ply laminated, circular determine the effects of shell lamination scheme and stiffeners on the reduced load-carrying capacity. The effect of geometric imperfection is also included. The analysis is based on the layerwise shell theory of Reddy, and the “smeared stiffener” technique is used to account for the stiffener stiffness. Nu cylinders under uniform axial compression is investigated to merical results for stiffened and unstiffened cylinders are presented, showing that imperfection-sensitivity is strictly related to the number of nearly simultaneous buckling modes.

Towards imperfection insensitive buckling response of shell structures-shells with plate-like post-buckled responses

2016 ◽  
Vol 120 (1224) ◽  
pp. 233-253 ◽  
Author(s):  
S. C. White ◽  
P. M. Weaver
Keyword(s):  
Variable Stiffness ◽  
Axial Stiffness ◽  
Asymptotic Model ◽  
Imperfection Sensitivity ◽  
Asymptotic Results ◽  
Buckling Mode ◽  
Design Variables ◽  
Non Linear ◽  
Buckling Stability ◽  
Post Buckling

ABSTRACTThe imperfection sensitivity of cylindrical panels under compression loading is shown to be not only reduced but effectively eliminated using stiffness tailoring techniques. Shells are designed with variable angle-tow (VAT) laminae, giving their laminates variable-stiffness properties over the surface co-ordinates. By employing an asymptotic model of the non-linear shell behaviour and a genetic algorithm, the post-buckling stability was maximised with respect to the VAT design variables. Results for optimised straight-fibre and VAT shells are presented in comparison with quasi-isotropic designs. In the straight-fibre case, small improvements in the post-buckling stability are shown to be possible but at the expense of the buckling load. In the VAT case, on the other hand, considerable improvements in the post-buckling stability are obtained and drops in axial stiffness and load associated with buckling are reduced to negligible levels. The improvements are shown to be a result of a benign membrane stress distribution prior to buckling and a localisation of the buckling mode. The asymptotic results are compared with non-linear finite-element analyses and are found to be in good agreement. Potential future multi-objective optimisation studies are discussed.

Local Buckling of Outstands in Stiffened Plates

1976 ◽  
Vol 27 (4) ◽  
pp. 277-291 ◽  
Author(s):  
W C Fok ◽  
J Rhodes ◽  
A C Walker
Keyword(s):  
Local Buckling ◽  
Strain Range ◽  
Maximum Load ◽  
Simple Expression ◽  
Stiffened Plates ◽  
Elastic Buckling ◽  
Analytical Prediction ◽  
Imperfection Sensitivity ◽  
Post Buckling ◽  
Overall Buckling

SummaryThis paper reports on an investigation of the effect of local elastic buckling of stiffener outstands on the overall behaviour of stiffened plates. A simplified mathematical model has been developed, based on the post-buckling analysis of the stiffener, and gives a simple expression which indicates that, for the plate geometry investigated, the maximum load carried varies asymptotically between the local critical load of the stiffener and a reduced Euler load. Also, there is a marked imperfection sensitivity arising from the interaction of the local and overall buckling modes. Experiments were carried out to confirm the analytical prediction for the elastic buckling behaviour of the stiffened plates. The models were constructed of Araldite, to allow large deformation within the elastic strain range. Experimental results showed very good agreement with the theory.

Appendix F: General Statistical Theory

2016 ◽  
pp. 503-521
Author(s):  
Karl G. Jöreskog ◽  
Ulf H. Olsson ◽  
Fan Y. Wallentin
Keyword(s):  
Statistical Theory ◽  
General Statistical
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