A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Optimization of supplemental damping in civil engineering structures
In the last decades the number of applications in civil engineering of special anti-seismic devices such as isolators and supplemental damping systems has been continuously growing thanks to their capability to provide higher safety levels to both new mission critical and existing structures. Passive control systems still appear very attractive with respect to active or semi-active control systems thanks to their capability to work without any external power source. The design of such systems, i.e. supplemental damping systems or seismic isolation ones, usually involves a trial and error process for the achievement of a satisfactory performance of the structural system. To improve competitiveness and effectiveness of passive control systems, their design should be tuned to an optimal value corresponding to a target performance. Aim of the thesis is the investigation of the effects of supplemental damping on the definition of its optimal value in typical passively controlled civil engineering structures, such as damper braced frames or isolated bridges. In case of supplemental damping systems, these are usually inserted in a bracing configuration into new or existing structures, thus being activated by interstory drifts. Structural dynamics of the damping-braced frame may be strongly affected not only in terms of damping but also eigenvalues and eigenvectors. In addition to this, the effect of the brace stiffness in energy dissipation mechanism of supplemental dampers is still not fully addressed in most design and optimization procedures. Even if it is well known that stiffer braces improve damping capacity, the exact value of the brace stiffness is usually neglected, while in practice brace dimensions have to be limited for functional or aesthetic requirements. This thesis properly addresses the effects of the frame to brace relative stiffness parameter on the dynamic behavior and the optimization procedure of single story and multistory frames. In case of seismic isolation, large displacements are usually ...
Optimization of supplemental damping in civil engineering structures
In the last decades the number of applications in civil engineering of special anti-seismic devices such as isolators and supplemental damping systems has been continuously growing thanks to their capability to provide higher safety levels to both new mission critical and existing structures. Passive control systems still appear very attractive with respect to active or semi-active control systems thanks to their capability to work without any external power source. The design of such systems, i.e. supplemental damping systems or seismic isolation ones, usually involves a trial and error process for the achievement of a satisfactory performance of the structural system. To improve competitiveness and effectiveness of passive control systems, their design should be tuned to an optimal value corresponding to a target performance. Aim of the thesis is the investigation of the effects of supplemental damping on the definition of its optimal value in typical passively controlled civil engineering structures, such as damper braced frames or isolated bridges. In case of supplemental damping systems, these are usually inserted in a bracing configuration into new or existing structures, thus being activated by interstory drifts. Structural dynamics of the damping-braced frame may be strongly affected not only in terms of damping but also eigenvalues and eigenvectors. In addition to this, the effect of the brace stiffness in energy dissipation mechanism of supplemental dampers is still not fully addressed in most design and optimization procedures. Even if it is well known that stiffer braces improve damping capacity, the exact value of the brace stiffness is usually neglected, while in practice brace dimensions have to be limited for functional or aesthetic requirements. This thesis properly addresses the effects of the frame to brace relative stiffness parameter on the dynamic behavior and the optimization procedure of single story and multistory frames. In case of seismic isolation, large displacements are usually ...
Optimization of supplemental damping in civil engineering structures
Losanno, Daniele (author)
2015-03-31
Losanno, Daniele (2015) Optimization of supplemental damping in civil engineering structures. [Tesi di dottorato]
Theses
Electronic Resource
Italian , English
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