Response analysis

Abstract: Modelling response processes response curves and surfaces efficiency in response duality of response relationships estimation of response in a world where risk is unimportant response efficiency under risk difficulties in field research aggregate response analysis economics of response research.

Abstract: An analytical modeling scheme is developed to assess the damageability of reinforced concrete buildings experiencing inelastic behavior under earthquake loads. The structural model used to discretize a building is capable of integrating ductile moment-resisting frames with shear-wall models and out-of-plane transverse elements to allow simulation of special interactions that are important in modeling overall structural behavior. The structural model is achieved using a combination of concentrated plasticity at member ends and a distributed flexibility rule that accounts for the spread of plasticity based on the variation of the contraflexure point during dynamic response. The inelastic behavior of components is monitored using a new hysteretic model that utilizes a nonsymmetric trilinear envelope and permits the modeling of stiffness degradation, strength deterioration, and pinching, respectively. The structural parameters, such as moment-curvature envelopes, etc., required for the inelastic seismic response analysis are computed in-core, using mechanical models and empirical equations that emerge from identification studies. The results of the response analysis are expressed as damage indices using a calibrated damage model based on energy and ductility. This enables the estimation of energy and strength reserves in the structure before collapse. Several examples are presented to illustrate the versatility of the proposed modeling schemes.

Abstract: This paper presents the first application of a semi-active damper system to an actual building. The Semi-active Hydraulic Damper (SHD) can produce a maximum damping force of 1000 kN with an electric power of 70 W. It is compact, so a large number of them can be installed in a single building. It is thus possible to control the building's response during a severe earthquake, because a large control force is obtained in comparison with a conventional active control system. This paper outlines the building, the control system configuration, the SHD, the control method using a Linear Quadratic Regulator, the response analysis results of the controlled building, and the dynamic loading test results of the actual SHD. The simulation analysis shows that damage to buildings can be prevented in a severe earthquake by SHD control. The dynamic loading test results of the SHD are reported, which show that the specified design values were obtained in the basic characteristic test. The control performance test using simulated response time histories, also shows that the damping force agrees well with the command. Finally, it is confirmed that the semi-active damper system applied to an actual building effectively controls its response in severe earthquakes. Copyright © 1999 John Wiley & Sons Ltd.