Modeling Moisture Gradient Effects On Bending Properties
Keywords:Finite elements, moisture gradients, stress-strain curves, mechanical properties, bimodu-larity, yellow-poplar
AbstractMoisture gradients are known to affect the bending properties of small clear beams, but no successful attempts have been made to quantify the influence of varying gradients. A three-dimensional, nonlinear finite element program was written for this purpose. Changes in compression and tension stress-strain relationships with varying equilibrated moisture contents were modeled from experimental results. These models were used with a paraboloid representation of moisture distribution to assign properties to individual elements in the finite element model. Comparisons with tests of equilibrated and non-equilibrated yellow poplar beams showed that the finite element model predicted expected trends, but moduli of rupture were consistently overpredicted.
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