High Gain Observer for the Estimation of Nonlinear Restoring Forces in Single Degree of Freedom Shear Buildings

Abstract To investigate the behavior of components and piping systems subjected to seismic loadings, the maximum restoring forces and maximum deformations of inelastic single-degree-of-freedom (SDOF) systems due to harmonic excitations and seismic floor motions are calculated and presented as diagrams. These systems have restoring forces characterized by a bilinear skeleton curve of a kinematic hardening rule. The diagrams show two types of characteristics, based upon which sinusoidal loadings can be categorized into force- and displacement-controlled loadings, and seismic loadings can be categorized into force- and displacement-dominant loadings, which are newly proposed herein. The characteristics of force- and displacement-dominant loadings are almost equal to those of force- and displacement-controlled loadings, respectively.

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Categorization of Dynamic Loading Into Force-Controlled Loading and Displacement-Controlled Loading

Volume 8: Seismic Engineering ◽

10.1115/pvp2018-85098 ◽

2018 ◽

Author(s):

Ichiro Tamura ◽

Shinichi Matsuura ◽

Ryuya Shimazu ◽

Koji Kimura

Keyword(s):

Dynamic Loading ◽

Kinematic Hardening ◽

Harmonic Excitation ◽

Degree Of Freedom ◽

Skeleton Curve ◽

Single Degree Of Freedom ◽

Single Degree ◽

Dynamic Loadings ◽

Restoring Forces

To investigate the behavior of inelastic single-degree-of-freedom systems, the maximum restoring forces and maximum deformations of the systems due to a harmonic excitation are calculated and drawn as a diagram. These systems have restoring forces characterized by bilinear skeleton curve of the kinematic hardening type. The diagram shows two types of characteristics, and the dynamic loadings can be categorized into force-controlled loading and displacement-controlled loading.

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The Study of a Single Degree of Freedom System with Time Dependent Parameters

Journal of the Royal Aeronautical Society ◽

10.1017/s0001924000055548 ◽

1967 ◽

Vol 71 (678) ◽

pp. 439-440 ◽

Cited By ~ 2

Author(s):

B. V. Dasarathy ◽

P. Srinivasan

Keyword(s):

Differential Equation ◽

General Solution ◽

Differential Equations ◽

Equations Of Motion ◽

Degree Of Freedom ◽

Time Dependent ◽

Single Degree Of Freedom ◽

Single Degree ◽

Stochastic Nature ◽

Restoring Forces

The equations of motion of many mechanical systems reduce to ordinary differential equations with time dependent parameters. A single degree of freedom system, with the damping and restoring forces varying with time according to the law … m (t+k)nhas been studied using the WKBJ approximation. The general solution of the differential equation can be used to arrive at the response of such time dependent systems, subjected to excitations which are specified to be of either deterministic or stochastic nature.

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