Resistance-foil strain-gage technology as applied to composite materials
A general review of existing strain-gage technologies as applied to orthotropic-composite materials is given. The specific topics addressed are gage-bonding procedures, transverse-sensitivity effects, errors due to gage misalignment, and temperature-compensation methods. The discussion is supplemented by numerical examples where appropriate. It is shown that the orthotropic behavior of composites can result in experimental error which would not be expected based on practical experience with isotropic materials. In certain cases, the transverse sensitivity of strain gages and/or slight gage misalignment can result in strain-measurement errors exceeding 50 percent.
On the birefringent-coating method of stress analysis for fiber-reinforced laminated composites
A general relation based upon laminated-plate theory is developed which relates the state of stress throughout the thickness of the fiber-reinforced composite laminate to experimentally determined surface strains. The usefulness of the developed relation is discussed through an example given for a typical graphite-epoxy structural laminate. Birefringent coatings employed as a method to determine laminate surface strains are investigated. Isochromatic disturbances in the vicinity of a laminate free-edge, due to a Poisson's ratio mismatch between coating and laminate and interlaminar stress transfer between discrete lamina of the laminate, are investigated through exact elasticity solutions.
The structure of Ibibio death prevention names
This paper examines death prevention names among the Ibibio in South-eastern Nigeria, from their structural perspectives. Ibibio death prevention names can generate and maintain some level of assurance and security that is vital for a child’s survival, given the implicit assumption that spiritual forces of some kind are at work. These names are believed to link their bearers to their past, ancestors and spirituality. This paper argues that these names represent enriching morphosyntactic properties that provide a window to the grammatical description of the Ibibio language. Their syntax is not constrained to a limited set of structures, thus they are structurally versatile and open ended, representing the various types and functions of sentences in the Ibibio language. The paper concludes with the claim that, in addition to the referential contents and metaphysical presuppositions of these names, they have other formal structural properties that distinguish them from ordinary Ibibio names.