http://web.mae.ufl.edu/nkim/Papers/paper19.pdf

Review of options for structural design sensitivity analysis. Part 1: Linear systems

The effectiveness of viscous and viscoelastic dampers for seismic response reduction of structures is quite well known in the earthquake engineering community. This paper deals with the optimal utilization of these dampers in a structure to achieve a desired performance under earthquake-induced ground excitations. Frequency-dependent and -independent viscous dampers and viscoelastic dampers have been considered as the devices of choice. To determine the optimal size and location of these dampers in the structure, a genetic algorithm is used. The desired performance is defined in terms of several different forms of performance functions. The use of the genetic approach is not limited to any particular form of performance function as long as it can be calculated numerically. For illustration, numerical examples for different building structures are presented showing the distribution and size of different dampers required to achieve a desired level of reduction in the response or a performance index. Copyright © 2002 John Wiley & Sons, Ltd.

Optimal placement of dampers for passive response control

Design strategies of viscous dampers for seismic protection of building structures: A review

Earthquake-resistant limit-state design for buildings

The usefulness of energy dissipation devices to reduce seismic response of structures is now well established. For a given installation of such devices in a structure, one can easily compute the level of response reduction achieved. However, the solution of an inverse problem of how many devices one would need to achieve a desired level of response reduction in a structure, or to achieve an expected level of performance from a structural system, is not quite as straightforward and well formulated. In this paper, a method is presented to obtain the amount of viscous and visco-elastic damping one would need to obtain a desired level of response reduction. The needed supplemental devices are also optimally distributed in the structure to achieve the best performance. To solve the optimal problem, a gradient-based optimization approach is used. To illustrate the application, numerical results for a 24-storey building structure are presented where the objective is to achieve the maximum reduction in the performance functions expressed in terms of the inter-storey drifts, base shear, or floor accelerations. Other forms of performance functions can also be treated similarly. Copyright © 2001 John Wiley & Sons, Ltd.

Optimal seismic response control with dampers

An efficient and systematic procedure is proposed for finding the optimal damper positioning to minimize the dynamic compliance of a 3-D shear building model. The dynamic compliance is expressed in terms of the transfer function amplitudes of the local interstorey drifts evaluated at the undamped fundamental natural frequency. The dynamic compliance is minimized subject to a constraint on the sum of the damping coefficients of added dampers. Optimality criteria are derived and the optimal damper positioning is determined via an original steepest direction search algorithm. This algorithm enables one to find an optimal damper positioning sequentially for gradually increasing damper capacity levels. A non-monotonic design path with respect to the total damper capacity level often appears in the application of this algorithm. A new augmented algorithm via parameter switching is devised to find this non-monotonic design path. Copyright © 1999 John Wiley & Sons, Ltd.

Non-monotonic optimal damper placement via steepest direction search

Application of an optimum design method to practical building frames with viscous dampers and hysteretic dampers

The secondary buckling and post-secondary-buckling behaviours of rectangular plates

A procedure of applying the perturbation method is presented for the incremental numerical analysis of materially and combined non-linear problems of discrete and discretized structral systems. Small but finite strain and stress increments are strictly distinguished from the strain rates and stress rates, respectively. It is shown that, by applying the perturbation procedure not only to the non-linear strain-displacement relations and equilibrium equations, but also to the constitutive equations in terms of rate quantities, all the governing equations can be satisfied to any desired accuracy at every instantaneous configuration in between the starting and terminal points of an incremental step. The proposed method provides also means of finding, to a desired accuracy, every point on an equilibrium path of a discrete system at which a new element will start yielding or unloading and possible critical points on the path. The significance of the proposed method is expected to be appreciated particularly in numerical investigations of critical behaviours and post-buckling behaviours.

Koji Uetani

Papers

Non-monotonic optimal damper placement via steepest direction search

Application of an optimum design method to practical building frames with viscous dampers and hysteretic dampers

The secondary buckling and post-secondary-buckling behaviours of rectangular plates

The incremental perturbation method for large displacement analysis of elastic‐plastic structures

Optimal damper placement for building structures including surface ground amplification