Frequency‐domain optimal viscous damper placement using lower‐bound transfer function and multimodal adaptability

Abstract

Summary A new concept of a “lower‐bound transfer function (LBTF)” and a new frequency‐domain optimal damper design method are presented. LBTF expresses an ideal performance for response control in the frequency domain under a constant sum of added damping coefficients (or the total cost of dampers). The effectiveness of the damper design for each mode can be captured visually through plotting the transfer function amplitudes of the model and the LBTF. An efficient generation method of LBTFs is also proposed. The proposed design method provides designs with multimodal adaptability (effective for multimodes). It does not require much computational load to implement the method since the optimization is conducted in the frequency domain, and the first‐order or second‐order sensitivities of the objective function can be derived analytically. The proposed design and the fundamental mode optimal damper placement are compared for shear‐mass systems and moment‐resisting frames through the transfer functions and the incremental dynamic analysis (IDA). It is demonstrated that the proposed designs effectively reduce the floor acceleration responses and the elastic deformation responses. Moreover, it is shown that the proposed designs can effectively reduce the elastic–plastic responses although the optimization is conducted for linear elastic models.

Rubber effect on metallic dampers used on the supports of steel cross members

“…As a result of these researches, many studies have been developed on linear dampers. Some of the most important of these are Wongprasert and Symans, 7 Lavan and Levy, 8,9 Attard, 10 Aydin et al, 11 Cimellaro and Retamales, 12 Lavan et al, 13 Cimellaro et al, 14 Lavan and Levy, 9 Lavan and Avishur, 15 Aguirre et al, 16 Lavan, 17 Elias et al, 18 Akehashi and Takewaki, [19][20][21][22][23][24] de Domenico et al, 25 Idels and Lavan, 26 and Pauletta et al 27,28 These linear dampers are still being studied by many researchers.…”