January 5, 2021 at 12:02 pm

peteroznewman

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ArraynYou should do a Mesh Convergence Study, changing the element size by a constant factor, such as 1.5 so do a series of element sizes such as: 0.4, 0.26, 0.18, 0.12, 0.08, 0.05 mmnResult quantities don't always change monotonically when the element sizes are much too large, but they should once they get smaller. Different results might converge from above or below the zero element size asymptote. nThe reason results converge as the element size is reduced is because the underlying physics is continuous, but finite elements is digitizing that continuum and introduces an approximation.nSome geometry, such as a sharp interior corner, or other boundary conditions such as Fixed Support, can have a Stress Singularity. The true solution at that point is infinite stress, so as the elements get smaller at that point, the stress continues to increase without limit. A crack tip is an example of a stress singularity. While the stress will not converge at a crack tip, other quantities will converge such as the J-integral, a quantity computed on a contour that encircles the crack tip.n