Effect of Imperfections on the Collapse of Rectangular Plates Using Variational Calculus.
Abstract
An analysis is made of the effect of initial imperfections in geometry on the collapse of simply-supported rectangular plates. A Reissner-type variational principle is employed to evaluate the load versus lateral displacement of elastic, elastic-plastic and orthotropic plates subject to compressive loading along two edges. Imperfection size and shape, plate thickness and aspect ratio, and for orthotropic material, the ply orientation is examined. The results indicate that the load-displacement curve is sensitive to the initial imperfection, particularly for elastic-plastic materials. The effect of plate size and aspect ratio are similar for all the plates considered with the collapse stresses higher for elastic plates than for elastic-plastic plates. The effect of plasticity becomes insignificant for thin plates when compared with plates with elastic properties. In general, it can be stated that the imperfection function determines the plate's collapse load. For orthotropic plates the effect of ply orientation is significant at aspect ratios less than 1 but relatively insignificant at higher values when comparing the minimum collapse stresses. The difference is dependent upon the magnitude of the ratio of Young's moduli in the major material axes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1979
- Accession Number
- ADA079905
Entities
People
- Lyle G. Peck
Organizations
- Air Force Institute of Technology