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Capacity-design methodology requires a realistic estimate of the expected strength of the members or components intended to undergo inelastic deformations (designated yielding members). To reach this aim, the ratio of expected to nominal yield stress has been included in the Provisions as Ry. The expected capacity of the designated yielding member is defined as Ry times the nominal strength of the member based on the desired yield mode. This expected strength is amplified to account for strain-hardening in some cases.
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