Abstract
A prevalent problem of mechanics is the differentiation of experimental information with respect to various directions, including the determination of cross derivatives. Simple methods for evaluating such derivatives along straight and curved directions are described. The concepts are demoinstrated at boundary and internal locations of in-plane and transversely loaded plates.
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Abbreviations
- f, F :
-
general function or dependent variable
- x, y, s, y, h :
-
coordinates
- Δξ:
-
arc length along ξ-direction
- u, v, w :
-
displacements
- θɛ, θη :
-
tangent angles to the ξ- and ν-coordinates and measured counterclockwise from the positive x-axis
- r, θ :
-
polar coordinates
- a :
-
radius of plate
- i, 1,2:
-
denote directions as subscripts
- ϕ, ψ:
-
angles
- N :
-
fringe order
- N :
-
fringe order
- λ:
-
wavelength
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Rowlands, R.E., Jensen, J.A. & Winters, K.D. Differentiation along arbitrary orientations. Experimental Mechanics 18, 81–86 (1978). https://doi.org/10.1007/BF02325001
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DOI: https://doi.org/10.1007/BF02325001