Ductile failure dynamic load

Anchor ductility is desirable for preventing brittle failure in the connection for two reasons 1) It provides greater margin against failure because it permits redistribution of load to adjacent anchors and 2) It reduces the maximum dynamic loads by energy absorption and reduction in stiffness. (Refer to ACI 349.) An anchor that is to be characterized as a ductile element should be shown by calculation to have adequate stretch length that is compatible with the ductility required. (See 3.11.5 for an example of how to do this.)... 

Flowever, should the elastic hmit be reached, the lack of an appreciable ductile range in the stress—strain curve for typical FRP laminates is likely to cause failure by direct rupture or tearing, particularly at locations of stress concentration or where free movement of the laminate is prevented, such as at joints or points of connection. In stmctures which rely on flexible dynamic response to attenuate the blast loading, joints should be designed ... 

FIG. II-5. Conversion of a triangular dynamic pressure into an equivalent static load. peak of the dynamic triangular puke (Pa) P static pressure (Pa) t duration of the triangular pulse (ms) T first excited period of the one-degree-of-freedom structure (ms) iax- tnaximum displacement at failure (m) Ay maximum elastic dkplacement (m) p maximum ductility. 

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