• 국제초고층학회논문집
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• 제9권4호
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• pp.325-334
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• 2020

This paper aims to evaluate the interfacial stress concentrations on connection between vertical through-plate and H-beam in CFT column. Full-scale experiments were performed on three specimens with varying thickness of the vertical through-plate to investigate the interfacial stress concentration factor in the connections. The specimens underwent brittle failure at the location where the steel beam is connected to the vertical through-plate before the steel beam reached its plastic moment. The strain data of the part were analyzed, and the sectional analyses were conducted to determine appropriate residual stress models. In addition, the stress concentration factor was quantified by comparing the analytical local behavior in which the stress concentration is not reflected and the experimental data reflecting the stress concentration. The results showed that the maximum reduction of the stress concentration factor due to an increase in the thickness of the vertical through-plate is 50.3%.

• Geomechanics and Engineering
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• 제19권3호
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• pp.201-215
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• 2019

A new approach of analyzing the displacements and stress of the surrounding rock for shallow tunnels excavated under non-axisymmetric displacement boundary conditions on a vertical surface is investigated in this study. In the proposed approach, by using a virtual image technique, the shear stress of the vertical ground surface is revised to be zero, and elastic solutions of the surrounding rock are obtained before stress revision. To revise the vertical normal stress and shear stress of horizontal ground surface generated by the combined action of the actual and image sinks, the harmonic functions and corresponding stress function solutions were adopted. Based on the Boussinesq's solutions and integral method, the horizontal normal stress of the vertical ground surface is revised to be zero. Based on the linear superposition principle, the final solution of the displacements and stress were proposed by superimposing the solutions obtained by the virtual image technique and the stress revision on the horizontal and vertical ground surfaces. Furthermore, the ground settlements and lateral displacements of the horizontal and vertical ground surfaces are derived by the proposed approach. The proposed approach was well verified by comparing with the numerical method. The discussion based on the proposed approach in the manuscript shows that smaller horizontal ground settlements will be induced by lower tunnel buried depths and smaller limb distances. The proposed approach for the displacement and stress of the surrounding rocks can provide some practical information about the surrounding rock stability analysis of shallow tunnels excavated under non-axisymmetric displacement boundary conditions on a vertical surface.

• 한국농공학회논문집
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• 제51권6호
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• pp.83-90
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• 2009

This study was carried out to evaluate the vertical stress properties in sandy soil according to changes of loading type in soil bin compacted three layers. The following conclusions and comparisons have been made based on careful analysis from theoretical and experimental methods. : When sandy soil subjected to cycle-loading, compression of foundation and diffusion of vertical stress increment(${\Delta}{\sigma}_2$) were influenced by magnitude of loading plate. When sandy soil subjected to reloading after removing of pre-loading, the distribution of ${\Delta}{\sigma}_2$ depth at one time of loading plate width was different from its distribution at more deep point cause of load hysteresis, so in case of design of structure, the effect of ${\Delta}{\sigma}_2$ as depth must be considered. The increment of vertical stress will be different as loading condition and foundation depth, the loading condition must be considered in case of structure design.

• 한국강구조학회 논문집
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• 제8권3호통권28호
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• pp.117-125
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• 1996

The stress patterns of vertical stiffener of plate girder bridge were examined by existing data of actual measurement stress for steel bridges and the structural details of vertical stiffener of plate girder bridge having seeked rationalization and abbreviation were investigated by 1/2 bridge model. As the results, the out-of-plane stress occur in the upper parts of vertical stiffner and fatigue cracks by the action of alternative stress is apt to occur in web plate of lower parts vertical stiffener. Also, the gap between lower parts of vertical stiffner and lower flange of plate girder bridge seeking rationalization and abbreviation is effective to adopt 100mm.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2006년도 춘계 학술발표회 논문집
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• pp.1358-1366
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• 2006

In order to study the effects of shell contents on the liquefaction resistance of the shelly sand, NGI cyclic simple shear tests were performed for the shelly sands with shell contents of 0%, 5%, 10%, 20% and 30% under the effective vertical stress of 50kPa, 100kPa and 150kPa for 40% and 55% of relative density, respectively. Cyclic simple shear test results showed that for the low effective vertical stress, liquefaction resistance increased rapidly with the increase of shell contents in both 40% and 55% relative density. On the other hand, for the high effective vertical stress, the liquefaction resistance increased slightly in 40% relative density whereas the resistance was almost same in 55% relative density. Liquefaction resistance decreased with increasing effective vertical stress for both 40% and 55% relative density. In the same effective vertical stress and shell contents, liquefaction resistance increased with the increase of relative density of sands.

• The Journal of Advanced Prosthodontics
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• 제13권2호
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• pp.79-88
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• 2021

Purpose. To assess peri-implant stress distribution using finite element analysis in implant supported fixed partial denture with occlusal schemes of cuspally loaded occlusion and implant protected occlusion. Materials and methods. A 3-D finite element model of mandible with D2 bone with partially edentulism with unilateral distal extension was made. Two Ti alloy identical implants with 4.2 mm diameter and 10 mm length were placed in the mandibular second premolar and the mandibular second molar region and prosthesis was given with the mandibular first molar pontic. Vertical load of 100 N and and oblique load of 70 N was applied on occlusal surface of prosthesis. Group 1 was cuspally loaded occlusion with total 8 contact points and Group 2 was implant protected occlusion with 3 contact points. Results. In Group 1 for vertical load, maximum stress was generated over implant having 14.3552 Mpa. While for oblique load, overall stress generated was 28.0732 Mpa. In Group 2 for vertical load, maximum stress was generated over crown and overall stress was 16.7682 Mpa. But for oblique load, crown stress and overall stress was maximum 22.7561 Mpa. When Group 1 is compared to Group 2, harmful oblique load caused maximum overall stress 28.0732 Mpa in Group 1. Conclusion. In Group 1, vertical load generated high implant stress, and oblique load generated high overall stresses, cortical stresses and crown stresses compared to vertical load. In Group 2, oblique load generated more overall stresses, cortical stresses, and crown stresses compared to vertical load. Implant protected occlusion generated lesser harmful oblique implant, crown, bone and overall stresses compared to cuspally loaded occlusion.

• 한국농공학회논문집
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• 제52권2호
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• pp.43-50
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• 2010

This study was carried out to evaluate the vertical stress properties in sandy soil according to changes of foundation condition in soil bin compacted three layers. The following conclusions and comparisons have been made based on careful analysis from theoretical and experimental methods. : When sandy soil subjected to circular uniform load, the vertical stress increments ($\Delta\sigma_z$) was increased as load increasing, the maximum values of $\Delta\sigma_z$ was achieved at the point loading axis, and $\Delta\sigma_z$ was not shown over at a distance of three times of loading plate width (B). The vertical stress increments were achieved largely at 80 % relative compaction (Rc) compared to 95 % relative compaction due to stress concentration in sandy soil. When sandy soil subjected to circular uniform load, the $\Delta\sigma_z$ differences between theoretical and experimental values as load increased were more increased and its maximum differences were achieved at stress axis. When gravel surface macadamized over sandy soil subjected to load, the $\Delta\sigma_z$ was concentrated to load axis as load increasing, so that macadamization will be decreased load transmission.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.70-86
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• 1996

The purpose of this study was to analyze the stress distribution in mandibular second premolars restored with different post and core techniques. Sixteen two-dimensional finite element model of mandibular second premolars restored with post and core and complete crown were developed according to the diameter, length, and material of post and core. Vertical force, 10N in magnitude, was applied first to the central fossa and then $45^{\circ}$ oblique force of same magnitude was applied to the buccal contact surface of buccal cusp. The obtained results were as follows : 1. Stress distribution within the dentin 1) Regardless of the material of the post and core and the diameter and length of the post, the pattern of stress distribution within the dentin was similar. 2) Maximum dentinal stress was observed on the lingual root surface of alveolar crest level with oblique loading and on lingual side of root dentin at the crown margin on vertical loading. 3) Cast post and cores produced the lowest dentinal stress concentrations and the highest stress concentration was observed in composite resin post and cores. 2. Stress distribution within the post and core 1) Within the amalgam and composite resin post and core, the patterns and maximum values of stress were similar. Maximum stress located at the central fossa of core portion on vertical loading and at the lingual junction of post and core with oblique loading. 2) Among the all post and cores, the cast post and core registered the highest stress concentration and maximum stress value within the post. Maximum stress located at the post apex on vertical loading and at lingual half of the post surface with oblique loading. 3) In case of Para-post and amalgam core, maximum stress located at the central fossa of core portion and lingual tip of the post head on vertical loading. With oblique loading, maximum stress located at the lingual half of the post surface.

• 대한치과보철학회지
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• 제34권1호
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• pp.101-124
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• 1996

In this study, we designed the finite element models of mandible with varying their connecting types between the prosthesis on implant fixture and 2nd premolar, which were free-standing case(Mf), precision attachment case(Mp), semiprecision attachment case(Ms) and telescopic case(Mt). The basic model of the designed finite element models, which contained a canine and the 1st & 2nd premolar, was implanted in the edentulous site of the 1st & 2nd molar by two implant fixtures. We applied the load in all models by two ways. A vertical load of 200N was applied at each central fossa of 2nd premolar and 1st implant. A tilting load of 20N with inclination of $45^{\circ}$ to lingual side was applied to buccal cusp tips of each 2nd premolar and 1st implant. And then we analyzed three-dimensional finite element models, making a comparative study of principal stress and displacement in four cases respectively. Three-dimensional finite element analysis was performed for the stress distribution and the displacement using commercial software(IDEAS program) for SUN-SPARC workstation. The results were as follows : 1 Under vertical load or tilting load, maximum displacement appeared at the 2nd premolar. Semiprecision case showed the largest maximum displacement, and maximum displacement reduced in the order of precision attachment, free-standing and telescopic case. 2. Under vertical load. the pattern of displacement of the 1st implant appeared mesio-inclined because of the 2nd implant splinted together. But displacement pattern of the 2nd premolar varied according to their connection type with prosthesis. The 2nd premolar showed a little mesio-inclined vertical displacement in case of free-standing and disto-inclined vertical displacement due to attachment in case of precision and semiprecision attachment. In telescopic case, the largest mesio-inclined vertical displacement has been shown, so, the 1st premolar leaned mesial side. 3. Under tilting load, The pattern of displacement was similar in all four cases which appeared displaced to lingual side. But, the maximum displacement of 2nd premolar appeared larger than that of the first implant. Therefore, there was large discrepancy in displacement between natural tooth and implant during tilting load. 4. Under vertical load, the maximum compressive stress appeared at the 1st implant's neck. Semiprecision attachment case showed the largest maximum compressive stress, and the maximum compressive stress reduced in the order of precision attachment, telescopic and free-standing case. 5 Under vertical load, the maximum tensile stress appeared at the 2nd implant's distal neck. Semiprecision attachment case showed the largest maximum tensile stress, and the maximum tensile stress reduced in the order of precision attachment, telescopic and free-standing case. 6. Under vertical load or tilting load, principal stress appeared little between natural tooth & implant in free-standing case, but large principal stress was distributed at upper crown and distal contact site of the 2nd premolar in telescopic case. Principal stress appeared large at keyway & around keyway of distal contact site of the 2nd premolar in precision and semiprecision attachment case, appearing more broad and homogeneous in precision attachment case than in semiprecision attachment case.

• 산업기술연구
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• 제16권
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• pp.181-189
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• 1996

Centrifuge model tests of cantilever retaining wall were performed to investigate the vertical stress distribution due to selfweight of backfill material. Model tests were carried out to find the effect of arching action on vertical stress distribution by changing the roughness of rigid boundary slope and the distance between retaining wall and boudary slope. A reduced scale model of cantilever retaining wall was made with concrete and Jumunjin Standary Sand with 80 % of relative density was used as foundation and backfill material. Centrifuge tests were performed by increasing g-level up to 40 g with measuring vertical stress induced by selfweight of backfill material. Test results on vertical stress distribution were analyzed and compared with results of Silo theory.