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Significant axial-force discrepancy between adjacent columns expected to demonstrate similar response indicates excessive damping from the c K K j damping contribution. This effect will magnify with shorter columns because their axial stiffness, and K j value, is larger. Given a dynamic loading condition, the cyclic bending of concrete sections will generate axial velocity. As axial extension increases with cracking and the ratcheting of yielding tensile rebar, velocity can become significant. This will cause improper damping to further effect results.
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