1616.9.3 Energy Methods

Static inelastic analysis using energy equilibrium may also be used. The structure does not need to remain elastic; however, the response ratio and rotation limits obtained from Table 1616.9.3 shall not be exceeded.

TABLE 1616.9.3 RESPONSE RATIO AND ROTATION LIMITS

ELEMENT	RESPONSE RATIO	ROTATION
Concrete slabs	µ < 10	θ< 4°
Post-tensioned beams	µ < 2	θ< 1.5°
Concrete beams	µ < 20	θ< 6°
Concrete columns	µ < 2	θ< 6°
Long span acoustical deck	µ < 2	θ< 3°
Open web steel joists	µ < 2	θ< 6°
Steel beams	µ < 20	θ< 10°
Steel columns	µ < 5	θ< 6°

For SI: 1 degree = 0.01745 rad.

Note: Table 1616.9.3 is intended for SDOF and simplified MDOF response calculations and a low level of protection. Table 1616.9.3 does not apply for explicit finite element methods that calculate the performance of the structural elements in response to the specified loading intensity. Steel joists: downward loading 6 degrees, upward loading ductility of 2.