• Structural Engineering and Mechanics
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• v.5 no.1
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• pp.1-19
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• 1997

A numerical procedure for dynamic analysis of structures including lateral-torsional coupling, axial force effect and soil-structure interaction is presented in this study. A simple soil-structure system model has been designed for microcomputer applications capable of reflecting both kinematic and inertial soil-foundation interaction as well as the effect of this interaction on the superstructure response. A parametric study focusing on inertial soil-structure interaction is carried out through a simplified nine-degree of freedom building model with different foundation conditions. The inertial soil-structure interaction and axial force effects on a 20-storey building excited by an Australian earthquake is analysed through its top floor displacement time history and envelope values of structural maximum displacement and shear force.

• Journal of the Korean Geotechnical Society
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• v.38 no.6
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• pp.17-28
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• 2022

The effect of the soil-structure interaction (SSI) on has been recently evaluated in shaking table tests. However, most of these tests were conducted on single-degree-of-freedom (SDOF) superstructures and a single-pile. This study investigates the inertial interaction effect of a multi-degree-of-freedom (MDOF) superstructure system with a group piles on a large-scale shaking table test. Whereas the SDOF superstructure system shows a single-frequency amplification tendency, the MDOF superstructure system exhibited amplification tendencies of the acceleration phase and frequency responses for multiple frequencies. In addition, the amplification phenomenon between the footing and the column-type superstructure exceeded that between the footing and the wall-type superstructure, indicating a greater inertial interaction effect of the column-type superstructure. The relationship between shear force and inertial force, the relative vertical and horizontal displacements on the footing was figured out. Also, the ananlysis of dynamic p-y curve at each depth was conducted. In summary, the MDOF and SDOP superstructure systems exhibited different behaviors and the column-type superstructure exerted a higher interaction effect than the wall-type superstructure.

• Structural Engineering and Mechanics
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• v.8 no.1
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• pp.53-72
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• 1999

The most important features of linear soil-foundation-structure interaction are reviewed, using stochastic modeling and considering kinematic interaction, inertial interaction, and structural distortion as three separate stages of the dynamic response to the free-field motion. The way in which each of the three dynamic stages modifies the spectral density of the motion is studied, with the emphasis being on interpretation of these results, rather than on the development of new analysis techniques. Structural distortion and inertial interaction analysis are shown to be precisely modeled as linear filtering operations. Kinematic interaction, though, is more complicated, even though it has a filter-like effect on the frequency content of the motion.

• Geomechanics and Engineering
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• v.34 no.6
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• pp.649-664
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• 2023

Structural inertial interaction is a representative the effect of dynamic soil-foundation-structure interaction (SFSI), which leads to a relative displacement between soil and foundation, period lengthening, and damping increasing phenomena. However, for a system with a significantly heavy foundation, the dynamic inertia of the foundation influences and interacts with the structural seismic response. The structure-to-foundation mass ratio (MR) quantifies the distribution of mass between the structure and foundation for a structure on a shallow foundation. Although both systems exhibit the same vertical factor of safety (FS_v), the MR and corresponding seismic responses attributed to the structure and foundation masses may differ. This study explored the influence of MR on the permanent deformation and seismic response of soil-foundation-structure system considering SFSI via numerical simulations. Given that numerous dimensionless parameters of SFSI described its influence on the structural seismic response, the parameters, except for MR and FS_v, were fixed for the sensitivity analysis. The results demonstrated that the foundation inertia of heavier foundations induced more settlement due to sliding behavior of heavily-loaded systems. Moreover, the structural inertia of heavier structures evidently exhibited foundation rocking behavior, which results in a more elongated natural period of the structure for lightly-loaded systems.

• Journal of the Earthquake Engineering Society of Korea
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• v.1 no.1
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• pp.11-17
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• 1997

Seismic analyses of structures were carried out in the past assuming a right base and Ignoring the characteristics of foundations and the properties of the underlying soil. Resent soil-structure interaction studies show that seismic response of structure can be affected significantly by these fators. Typical effects of the soil-structure interaction are the kinematic interaction of a rigid massiess foundation and the inertial interaction between underlying soil and structure. The kinematic interaction effect is particularly important for embedded foundations and can be ignored for surface foundations with vertically propagating waves. In this study, seismic response of structure was investigated with four buildings in Mexico City considering only the inertial interaction effect and using the E-W components of the 1985 Mexico City earthquake records. The study was carried out for surface foundations and pile foundations with linear and nonlinear soil conditions, comparing the results with those of the rigid base.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.6
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• pp.641-652
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• 2000

The effect of block arrangement has been investigated on the particle deposition in the specified collecting cell of two-stage electrostatic precipitator by numerical analysis. Recirculation zone existed at the downstream of the block in the collecting cell, and the particles entering the recirculation zone were deposited on the collecting plate. Particle trajectory and deposition had considerably different phenomenon according to electrostatic and inertial effect, which depended on inlet mean velocity, electrostatic number, and particle diameter in the collecting cell. The total collection efficiency reached a minimum value through an interaction of electrostatic and inertial effect. In the computational domain, total collection efficiency for the case of two blocks in the computational domain was more than that of one block at the relative small electrostatic number. However as the block distance and inertial effect increased, the difference between the collection efficiency of two cases decreased. In the range of relatively small particle size total collection efficiency was always superior to particle collection efficiency that was predicted by Deutsch equation.

• Journal of the Korean Geotechnical Society
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• v.21 no.2
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• pp.37-46
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• 2005

In the field of earthquake engineering, recent improvements in many areas, such as seismological source modeling, analysis of travel path effects, and characterization of local site effects on strong shaking, have led to significant advances in both code-based and more advanced procedures for evaluating earthquake ground motions. A missing link, however, is empirically verified design procedures fur assessing the effects of soil-structure interaction (SSI). Available Soil-Structure Interaction (SSI) analysis techniques range from simple substructure-type procedures to relatively sophisticated finite element procedures. The most common substructure approach for foundation-soil interaction is to use a frequency-dependent and complex-valued impedance function. This study uniquely evaluates impedance functions for two well-instrumented sites w significant inertial SSI effects using a system Identification technique. The system identification analysis results are then compared to predictions from a simple theoretical model to gain insight into the inertial interaction effect in the subject sites.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.2
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• pp.165-178
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• 2000

In this study the effects of block distance have been investigated on the particle deposition efficiency in the collecting cell of two-stage electrostatic precipitator by numerical analysis. Particle trajectories have been changed by the electrostatic and inertial force of particle with the inlet velocity electrostatic number and particle diameter. The total deposition efficiency has a minimum value by the interaction between the effect of particle inertial force and electrostatic force in the collecting cell. The increase of block distance makes the total deposition efficiency decrease under the range of the particle size which has the minimum deposition efficiency. However beyond the range of particle size which has minimum deposition efficiency total deposition efficiency has no trend with the variation of block distance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.744-749
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• 2005

In this paper, a lens actuator for mobile devices is proposed using stack type piezoelectric materials. In general, the deformation of PZT actuators is not enough for lens motion when the allowed voltage is applied. The small stroke problem can be solved by accumulating a lot of small displacements in high frequency. In this paper, a new inch-worm type model for focusing actuator is suggested based on the interaction of inertial and frictional forces. Theoretical analysis and simulation using ANSYS are performed to verify the feasibility of the inch-worm PZT actuator model. Various types of clamps are considered to determine the effect of frictional force on the motion, and appropriate clamp-actuator models are proposed. The proposed models are experimentally verified and the experimental results show high correspondence with theoretical and simulated values. The inch-worm type focusing actuator enable a large stroke with 7.79 mm/sec with 10kHz and 10V.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.292-300
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• 2024

Kinetic simulations have been performed on an Inertial Electrostatic Confinement Fusion (IECF) device. These simulations were performed using the particle-in-cell (PIC) method to analyze the behavior of ions in an IEC device and the effects of some parameters on the Confinement Time (CT). CT is an essential factor that significantly contributes to the IEC's performance as a nuclear fusion device. Using the PIC method, the geometry of a two-grided device with variable grid radius, the number of cathode grid rings, variable pressure and different dielectric thickness for the feed stalk was simulated. In this research, with the development of previous works, the interaction of particles was simulated and compared with previous results. The simulation results are in good agreement with the previous results. In these simulations, it was found that with the increase of the dielectric thickness of the feed stalk, the electric field was weakened and as a result, the confinement time was reduced. On the other hand, with the increase of the cathode radius, the confinement time increased. Using the results, an IEC device can be designed with higher efficiency and more optimal CT for ions.