Question

Describe the response of concrete subjected to repeated loading and unloading with the help of a graph

Answer 1

Stress- Strain Curve under repeated loading and on looding reloading Stress C fuppor a (Cyclic loading ) huprolun Strouin (E) # From the graph the loading and unloading Curres do not coincide and also not parallel to the mitial loadng Curves. * The average slope of Curves is to the the einbading and cloading plastic strain [inversely proportion * The reloading Curves are linear up to the unloading Curve intersection then after there is softening in response. * The unloading carve is strongly dependent on the rather than the unloading plastic strain sation of unloading strain * This stres-strain graph suggests that there is Suffiness degradation for entire stress - Strain care beyond clastic.

* There is no additional strain accumulation in the reloading Curve until the stress carceed stability limit. $ Concrete shows hysteretic behaviour cohore with in tho hystergis loop: the area ☆ It represents the energy dissipated during a Gydle, become more when the unloading strain mcrcases. * From this esperimental graph the Strain is always grater than the Strain (partially or fall unloading). envelope rcoading envelope anloading