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- Period – Generally, the period (T) of the TMD is chosen to closely match the structural period to be counteracted, taken as the first period of vibration of control model. Note that, although the mass does not affect the period of the TMD, it does affect how strongly the TMD affects the rest of the structure, with larger masses typically having a larger effect. The period of the TMD is given by:
Once the period of the TMD is derived, TMD length is calculated from this value and gravity. This length, along with gravity and the arbitrary mass value, are then converted into the effective link stiffness of the U2 and U3 directions, given as Mg/L. This being the case, the length of the TMD in the real structure is not explicitly modeled, but is accounted for in the link property.
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