• The korean journal of orthodontics
• /
• v.15 no.1
• /
• pp.43-54
• /
• 1985

Recently, rapid palatal expansion technique is widely used for the correction of the skeletal imbalance in Cl III malocclusion patients. There were many studies about the cephalometric changes to rapid palatal expansion but quantitative analysis were small. The purpose of this study was to analysis the stresses and displacement of the maxilla in human dry skull to rapid palatal expansion. The results were as follows: 1. The anterior portion of palate show more lateral and inferior displacement than the posterior portion. But the posterior portion show more anterior displacement. 2. In transpalatal suture area, the medial portion show more anterior and inferior displacement than the lateral portion. But the lateral portion show more lateral displacement than the medial portion. 3. In mid-sagittal plane, the lower portion (palatal area) of maxilla show more anterior, lateral, inferior displacement than the upper portion (frontamaxillary stuture area). 4. In zygomatic arch, the adjacent area to maxilla show tonsil. stresses and the adjacent area to frontal bone show compressive stresses. 5. The sequence of stress bearing area to R.P.E. is upper retromolar area, upper 1st molar, 1st premolar, 2nd premolar, anterior segment of teeth.

• Structural Engineering and Mechanics
• /
• v.80 no.6
• /
• pp.737-747
• /
• 2021

The objective of seismic resilience is to maintain or rapidly restore the function of a building after an earthquake. An efficient tilt mechanism at the member level is crucial for the restoration of the main structure function; however, the damage resistance of the members should be the main focus. In this study, through a comparison with the classical Flamant theory of local loading in the elastic half-space, an elastomechanical solution for the axial-stress distribution of a reinforced-concrete (RC) rocking column was derived. Furthermore, assuming that the lateral displacement of the rocking column is determined by the contact surface rotation angle of the column end and bending and shear deformation of the column body, the load-lateral displacement mechanical model of the RC rocking column was established and validated through a comparison with finite-element simulation results. The axial-compression ratio and column-end strength were analyzed, and the results indicated that on the premise of column damage resistance, simply increasing the axial-compression ratio increases the lateral loading capacity of the column but is ineffective for improving the lateral-displacement capacity. The lateral loading and displacement of the column are significantly improved as the strength of the column end material increases. Therefore, it is feasible to improve the working performance of RC rocking columns via local reinforcement of the column end.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.6
• /
• pp.59-66
• /
• 1995

The hot electron induced effective channel length modulation (${\Delta}L_{H}$) and HEIP characteristics in PMOSFET's after bidirectional stress are presented. Trapped electron charges in gate oxide and lateral field are calculated from the gate current model, and ${\Delta}L_{H}$(${\Delta}L_{HD},\;{\Delta}L_{HS}$) is calculated using trapped electron charges and lateral field. It has been found that ${\Delta}I_{d}$and ${\Delta}L_{H}$ are more affected by the stress order (Forward-Reverse of Reverse or Reverse-Forward) than the stress direction, and they vary logarithmically with the stress time. In contrast, ${\Delta}V_{t}$ and ${\Delta}V_{pt}$ are more affected by the stress direction thatn the stress order. The correlation between ${\Delta}V_{pt}$ and the stress time can be explanined as the following polynomial functin: ${\Delta}V_{pt}$=AT$^{n}$. It has also been shown that PMOSFET degradation is related with the gate current and the effects of ${\Delta}V_{pt}$ is the most significant.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.03a
• /
• pp.1155-1165
• /
• 2008

Full scale size model tests of the top-base foundation was performed in siwha marine clay and the site measurement results were compared with the analytical results from finite different programs, FLAC-2D to investigate the behavior of top-base foundation. The stress distribution obtained from the numerical analysis for the various types of foundation were compared and analysed during the application of allowable load as well as yield load. It was found that the top-base foundation prevents the lateral deformation of soft ground and stress dispersion effect to reduce the surface settlement, and that the foundation creates uniform stress distribution around it, therefore increasing bearing capacity.

• Tribology and Lubricants
• /
• v.10 no.3
• /
• pp.62-70
• /
• 1994

An analytical model of the stress field caused by sliding indentation of brittle materials is developed. The complete stress field is treated as the superposition of applied normal and tangential forces with a sliding blister approximation of the localized inelastic deformation occuring just underneath the indenter. It is shown that lateral cracking is produced by the sliding blister stress field and that median cracking is caused by the applied contact forces. The model is combined with an experimental volume change measurements to show that the relative magnitude of tensile stresses governing lateral crack and median crack growth varies with the magnitude of the applied load. This prediction is consistent with the different regimes of experimentally observed cracking in soda-lime glass.

• KCI Concrete Journal
• /
• v.13 no.1
• /
• pp.53-60
• /
• 2001

Tests of cylindrical concrete specimens under lateral confining pressure of up to 5,000 psi were conducted for two different axial loading cases: monotonic compression and monotonic tension. The purpose of this experimental investigation is to provide stress-strain characteristics of plain concrete in triaxial stress conditions. Lateral confining pressure levels, loading rates, and strength of concrete specimens are varied as parameters. The loading rates are $34.75$\times$10^{-5}$ in/in/sec for fast, $\times$$6.95x10^{-5}$ in/in/sec for normal. and $0.579$\times$10^{-5}$ in/in/sec for slow loading cases. The concrete specimens used in the experiment have compressive strength of 3,500 psi and 6,500 psi, respectively. Findings of this experiment include dependency of the stress-strain behavior of concrete on the above parameters under two different types of loading conditions. The parametric study includes a series of 106 triaxial tests.

• Design & Manufacturing
• /
• v.14 no.3
• /
• pp.23-30
• /
• 2020

Laser Assisted Thermo-Compression Bonding (LATCB) has been proposed to improve the "chip tilt due to the difference in solder bump height" that occurs during the conventional semiconductor chip bonding process. The bonding module of the LATCB system has used a piezoelectric actuator to control the inclination of the compression jig on a micro scale, and the piezoelectric actuator has been directly coupled to the compression jig to minimize the assembly tolerance of the compression jig. However, this structure generates a lateral force in the piezoelectric actuator when the compression jig is tilted, and the stacked piezoelectric element vulnerable to the lateral force has a risk of failure. In this paper, the optimal design of the flexure hinge was performed to minimize the lateral force generated in the piezoelectric actuator when the compression jig is tilted by using the displacement difference of the piezoelectric actuator in the bonding module for LATCB. The design variables of the flexure hinge were defined as the hinge height, the minimum diameter, and the notch radius. And the effect of the change of each variable on the stress generated in the flexible hinge and the lateral force acting on the piezoelectric actuator was analyzed. Also, optimization was carried out using commercial structural analysis software. As a result, when the displacement difference between the piezoelectric actuators is the maximum (90um), the maximum stress generated in the flexible hinge is 11.5% of the elastic limit of the hinge material, and the lateral force acting on the piezoelectric actuator is less than 1N.

• Journal of architectural history
• /
• v.22 no.6
• /
• pp.47-58
• /
• 2013

The purpose of this study is to analyze the cause of damage to the three storied stone pagoda of Bulguksa temple in GyeongJu. This report is attempted to making reinforcement and conservation plan through investigating and analyzing the cause of damage to that. The damage is caused by occurring of stress, degrading of stone strength, changing of underground soil structure, natural disasters and so on. Compressive stress, shear stress, bending stress and lateral pressure affected to the pagoda since built up. Ultrasonic examination data tells the strength of the stone. According to this result, strength of the stereobate stone materials is enough to support the weight of the upper ones. But we could found many other factors of the damage could consider, for example the problems occurred on building the pagoda construction and the weakness of the stone material(soft rock). And many environmental factors being changed in soil structure(subsidence of soil and degradation of bearing power of soil and freezing and melting of soil) can be seen as the cause of the damage. Natural disasters like earthquake, lightning and heavy rain were also thought to give direct impact to the damage. At last Concentration of compressive stress caused the crack and exfoliation on the stone materials and shear stress, bending stress and lateral pressure were main causes of the stereobate stone materials shearing.

• The korean journal of orthodontics
• /
• v.15 no.1
• /
• pp.7-22
• /
• 1985

The purpose of this study was to analyze the stress distribution and the displacement in the maxillary complex after the application of the reverse headgear. The direction of force was parallel to the occlusal plane. Orthopedic force,300gm, was applied to the maxilla of the dry human skull in a forward direction. The stress distribution and the displacement within the maxillary Complex was analyzed by a 3-dimensional finite element method. The results were as follows: 1. The stress distribution at the molar region was greater than that at the anterior. 2. The stress distribution at the lateral side of the premaxilla was greater than that at the middle aide, especially high stress was noted at the canine eminence. 9. Compressive stress was noted only at the frontozygomatic suture of the zygomatic arch. 4. A forward, upward, and sideward displacement was noted at the entire nodal points of the zygomaticomaxillary suture portion. A displacement with a slight rotation was observed on the transverse palatine suture. 5. The maximum stress was observed at the lateral side of the maxillary tuberosity area, and generally the forward and downward displacement was noted at all this area.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.14 no.3
• /
• pp.39-48
• /
• 2010

Improved seismic performances of RC bridges can be attained by sufficient ductilities of piers, which can be obtained by providing sufficient lateral confinements to the plastic hinge regions of piers. The cross sectional shape and the amount of lateral reinforcements are key parameters in the determination of effective confinements. Even though identical amounts of lateral reinforcement are provided, the effective confinement differs due to different spacing, arrangements, hook details and so on. Unlike circular sections in which confinement is exerted by mere hoop reinforcements, cross-ties are arranged in square or rectangular sections to enhance the effective confinements. The stress-strain relationship of confined concrete is varied by how to consider these cross-ties. In this study, the stress-strain relationships of confined concrete with cross-ties are investigated experimentally and their mechanical characteristics are estimated by comparison with other empirical equations.