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11.2: Loading/Unloading Condition

  • Page ID
    33956
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    In the 1-D case the plastic flow rule is reduced to the following statement:

    \[\dot{\epsilon}^p > 0 \quad \sigma = \sigma_o \]

    \[\dot{\epsilon}^p < 0 \quad \sigma = −\sigma_o \]

    \[\dot{\epsilon}^p = 0 \quad \sigma_o < \sigma < −\sigma_o \]

    11.2.1.png
    Figure \(\PageIndex{1}\): The flow stress \(|\sigma_o|\) is assumed to be identical in tension and compression in the rigid-perfectly plastic material model.

    In the case of unloading, the stress follow the path CD on the \(\sigma-\epsilon^p\) graph. If the strain rate is an independent variable, the path of all unloading cases is the same CBO, as shown in Figure (\(\PageIndex{1}\))


    This page titled 11.2: Loading/Unloading Condition is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Tomasz Wierzbicki (MIT OpenCourseWare) via source content that was edited to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.