• International Journal of CAD/CAM
• /
• v.9 no.1
• /
• pp.79-83
• /
• 2010

Tidal bore is a peculiar nature phenomenon which is caused by the lunar and solar gravitation. Based on the physical characters of tidal bores, in this paper we propose a novel method to model and render this phenomenon, especially the tidal waves in Qiantang estuary. According to Boltzmann equation for tidal waves, we solve it with the novel triangle mesh of Kinectic Flux Vector Splitting (KFVS) mode. Then a method combining a curve forecasting wave and particles model is proposed to render the dynamic scenes of overturning tidal waves. Finally, with some rendering technologies, various realistic tidal waves under diversified conditions is rendered in real time.

• Structural Engineering and Mechanics
• /
• v.64 no.4
• /
• pp.461-472
• /
• 2017

The dynamic tests of recycled aggregate concrete (RAC) are carried out, the rate-dependent mechanical models of RAC are proposed. The dynamic mechanical behaviors of RAC frame structure are investigated by adopting the numerical simulation method of the finite element. It is indicated that the lateral stiffness and the hysteresis loops of RAC frame structure obtained from the numerical simulation agree well with the test results, more so for the numerical simulation which is considered the strain rate effect than for the numerical simulation with strain rate excluded. The natural vibration frequency and the lateral stiffness increase with the increase of the strain rate. The dynamic model of the lateral stiffness is proposed, which is reasonably applied to describe the effect of the strain rate on the lateral stiffness of RAC frame structure. The effect of the strain rate on the structural deformation and capacity of RAC is analyzed. The analyses show that the inter-story drift decreases with the increase of the strain rate. However, with the increasing strain rate, the structural capacity increases. The dynamic models of the base shear coefficient and the overturning moment of RAC frame structure are developed. The dynamic models are important and can be used to evaluate the strength deterioration of RAC structure under dynamic loading.

• Journal of the Korean Society of Industry Convergence
• /
• v.26 no.6_3
• /
• pp.1315-1323
• /
• 2023

Rehabilitation assistive devices not only assist the rehabilitation therapy and daily life of the disabled and the elderly, but also assist the labor of their caregivers, so various functions are required to improve their quality of life. In this study, a design method considering its practicality is introduced for an active rehabilitation assistive device that can perform both standing and walking assistance by driving various actuators. For this purpose, the force required to assist standing was calculated using statics with the body segmentation method. Also, the overturning stability of the device was verified for various physical conditions and postures. The actuator in the active rehabilitation assistive device was operated by a patient using a graphical user interface in an embedded computer and a touch panel for easy usage. The detailed design was performed for implementation through the help of 3D-CAD and the finite element analysis, and a prototype was produced. Finally, it was proven that the design goal was satisfied by experimental validation.

• Journal of the Korean Geotechnical Society
• /
• v.29 no.11
• /
• pp.85-97
• /
• 2013

Electric pole foundations for overhead catenary system of railroad should be designed so that they may resist significant overturning moment but relatively small vertical forces. Also they should have proper shapes to be installed at restricted narrow areas adjacent to railroad track. In this paper the moment responses of rectangular pole foundations according to their shapes were investigated numerically. A three-dimensional finite element method was developed and verified so that the numerical behaviors of the foundation resisting the overturning moments were compared reasonably well with those from an existing real-scale load test. The influences of aspect ratio, varying section with depth and loading directions for rectangular section were investigated using the developed numerical method. From the numerical results, the optimized shapes of pole foundation for more effective and economic installation adjacent to railroad track are proposed.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2000.10a
• /
• pp.215-223
• /
• 2000

In this study, the effect of stiffness ratio between base frame and anchorgae is evaluated and the seismic verification of nuclear power plant equipment anchorage is performed for typical equipment. The stiffness ratio between base frame and anchorage is mainly controlled by the effective height of side wall plate. And, the change of that stiffness ratio cause the large shift or ovreturning axis of equipment base. This shift of overturning axis of equipment base is able to reduce the factor of safety about 10%. Therefore, the adequate method for evaluating of effective height of side wall is required as further study.

• Proceedings of the Korean Geotechical Society Conference
• /
• 1992.10a
• /
• pp.75-86
• /
• 1992

The elevation of reclamation work in the coastal area for the industrial complex is determined through the investigation and review of marine conditions, drainage plan and fill materials. The embankment to be constructed with crushed stone on the soft soil should be safe against the wave force, immediate and long term consolidation settlement, overturning and sliding due to self-weight and other forces. Because of lack of fill material from the borrow pit, the soft marine clay to be dredged shall be used as the reclamation material. And Paper Drain Board is used as the improvement method for the deep soft clay strata.

• Geotechnical Engineering
• /
• v.4 no.2
• /
• pp.15-24
• /
• 1988

To identify the stability of cantilever retaining wall in safe state by the deterministic method, these potential modes of such geotechnical failures as bearing capacity, horizontal sliding and overturning are analysed using Advanced First Order Second Moment (AFOSM) method. All design variables are assumed of the normal distribution and to be statistically independent. Considering the correlations between the single modes, structural system reliability index is 2. 05. Even if the safety factors are larger than the required value in the codes' by the conventional deterministic method, the system reliability of this structure may not be Judged to be safe state since the system reliability index is much lower than general value of 3.

• Journal of Drive and Control
• /
• v.11 no.3
• /
• pp.22-30
• /
• 2014

In this research, the energy stability level method is used for examining the stable state of Field Robot under effects of swing motion, at particular postures of manipulator, and terrain conditions. The energy stability level is calculated by using the dynamic models of Field Robot, subjected to the concept of equilibrium plane and support boundary. The results, simulated by using computing program for estimating the potential overturning of Field Robot, supply useful predictions of stability analysis for designers and operators.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.1
• /
• pp.411-417
• /
• 2013

The moment responses of electric pole foundations for a railroad were investigated using real-scale load tests. Large overturning moments were applied to two square rigid piles with a 1.1 m width and a 2.2 m embedded depth. Two different installation methods-with and without a form-were applied to evaluate the influence of the form work on the moment capacities of the foundations. The reduction of ground strength caused by the excavation without a form is more pronounce than the decrease of frictional strength due to the smooth concrete surface with a form. From the test results, it is found that the current design method which applies a proportional coefficient to consider the effect of a form work is not appropriate. When the normal and frictional stressed is considered separately, the effect of a form work can be estimated reasonably by reducing the friction angle between soil and foundation by 20%.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.11a
• /
• pp.338-344
• /
• 2003

The seismic analysis method of spent fuel storage structures for PHWR plant is introduced in comparison with the method for PWR plant. Investigating the structural characteristics of the storage structures, the former is vertically stacked fuel storage trays, while the latter is welded honeycomb type structure. However, as both structures are submerged and free standing, the analysis methods to anticipate the seismic response of both structures are complicated. For the better estimation of actual seismic response, how to model the dynamic properties and the structural behaviour is the key issue. In this paper, the overall procedures of the seismic modelling and stability check for seismic sliding and overturning of the two different storage structures are discussed in the viewpoint of analysis reliability