• Title/Summary/Keyword: Lateral

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Lateral stiffness of corner-supported steel modular frame with splice connection

  • Yi-Fan Lyu;Guo-Qiang Li;Ke Cao;Si-Yuan Zhai;De-Yang Kong;Xuan-Yi Xue;Heng Li
    • Steel and Composite Structures
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    • v.48 no.3
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    • pp.321-333
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    • 2023
  • This paper proposes a comprehensive investigation on lateral stiffness of corner-supported steel modular frame using splice connection. A full-scale modular frame with two stacked steel modules under lateral load is tested. Ductile pattern in the transfer of lateral load is found in the final failure mode. Two types of lateral stiffness, including tangent stiffness and secant stiffness, are defined from the load-displacement due to the observed nonlinearity. The difference between these two types of stiffness is found around 20%. The comparisons between the experimental lateral stiffness and the predictions of classical methods are also conducted. The D-value method using hypothesis of independent case is a conservative option for predicting lateral stiffness, which is more recommended than method of contraflexural bending moment. Analyses on two classical short-rod models, including fix-rod model and pin-rod model, are further conducted. Results indicate that fix-rod model is more recommended than pin-rod model to simplify splice connection for simulation on lateral stiffness of modular frame in elastic design stage.

A Study on the Attrition of Maxillary Lateral Incisors in Korea (상악 측절치의 교모에 관한 연구)

  • Lim, Byung-Chul
    • Journal of Technologic Dentistry
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    • v.18 no.1
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    • pp.117-127
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    • 1996
  • This study was aimed to help the construction of esthetic dental prosthesis by investigation of the factors affecting on the atterition position and attrition angle of maxillary lateral incisors. Therefore 197 complete cast of maxillary and mandibualar extracted form the student of K. college were subjected for this study, and result throught the study are as follows. 1. None attrite rate of the maxiilary right lateral incisors was about 16.2% and that of the maxillary left lateral incisors was about 32.4% of examined teeth. 2. Throught mesiodistal attrition area 1) It showed that right lateral incisors was the most frequence in attrition of mesial area of incisal edge, and left lateral incisors was the most frequence in attrition of mesial and mid area of incisal edge. 2) It showed that square type arch was more frequence in attrition of all incisal edge, and ovoid type arch was more frequence in the attrition of mid area of incisal edge, and ovoid type arch was more frequence in the attrition of mid area of incisal edge, and taper type arch was more frequence in the attrition of mesial area of incisal edge than it of average frequence of right lateral incisors, by dental arch type. 3) It showed that square type arch was more frequence in the attrition of all area and mid area of incisal edge, and ovoid type arch was more frequence in the attrition of mid area of incisal edge, and taper type arch was more frequence in the attrition of mesial and distal area of incisal edge than it of average frequence of left lateral incisal, by dental arch type. 4) Sex, vertical overlap, horizontal overlap, incisal guide angle, did not affect significantly to throughout mesiodistal attrition, statistically 3. Throughout labiolingual attrition quantity. 1) It showed that throughout labiolingual attrition quantity was more attrition in order of taper type arch < ovoid type arch < square type arch, by dental arch type. 2) It showed that throughout labiolingual attrition qauntity was more attrition when the length of horizontal overlap is shorter than it of other, by horizontal overlap. 3) Throughout labiolingual attrition quantity of right lateral incisors showed that male was more attrition than it of female. 4) Vertical overlap, incisal guide angle, sex on left lateral incisors did not affect significantly to throughout labiolingual attrition, statistically. 4. Attrition angle 1) It showed that average attrition anlge of right lateral incisors were $30{\pm}13.02$ degree, and it of left lateral incisors were $26{\pm}13.37$ degree. 2) It showed that taper type arch have a bigger attrition angle than it of average of lateral incisors, and square tape arch have a smaller attrition angle than it of average of lateral incisors, by dental arch type. 3) It showed that horizontal overlap of 2.1mm above have a bigger attrition angle than it of average, by horizontal overlap. 4) It showed that female have a bigger attrition angle it of male, by sex.

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Analysis of the Characteristics of Maxillary Supernumerary Lateral Incisor (상악 측절치 과잉치의 특징 분석)

  • Nah, Jeungseon;Lee, Koeun;Kim, Misun;Nam, Okhyung;Choi, Sungchul;Lee, Hyo-Seol
    • Journal of the korean academy of Pediatric Dentistry
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    • v.49 no.1
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    • pp.25-34
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    • 2022
  • This study aimed to investigate a quantitative analysis of the anatomical characteristics of the maxillary supernumerary lateral incisor and its relationship with lateral incisors. Forty-four supernumerary lateral incisors from 43 patients were evaluated for analyzing the position, shape, direction, and relationship between the supernumerary lateral incisor and the normal lateral incisors, using cone-beam computed tomography (CBCT). To compare the size of crown, the mesio-distal width was measured and the Nolla stage was used for evaluating the degree of root development to compare tooth maturity. The supernumerary lateral incisors were in the normal direction at a rate of 90.9%, and in a supplemental shape at a rate of 84.1%. The supernumerary lateral incisor was smaller in size compared to the adjacent lateral incisor and opposite lateral incisor (p < .0001). There was no statistically significant difference in the development stage of root. Based on these results, the supernumerary lateral incisor is similar with the lateral incisor, but has a difference in the size of crown. It is necessary to distinguish the supernumerary lateral incisor from the lateral incisor precisely to reduce clinical complications.

Characteristics of the Lateral Resistance of Pile according to the Lateral Loading Rate in Dense Sand (조밀한 모래지반에서 수평재하속도에 따른 말뚝의 수평저항 특성)

  • Gichun Kang;Hyejeong Park;Seong-kyu Yun;Jiseong Kim
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.3
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    • pp.97-103
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    • 2023
  • Recently, research on the lateral resistance of pile foundations has been actively conducted. In experimental studies on the lateral resistance of pile foundations, displacement control or load control methods are used. However, in the case of the displacement control method, the lateral resistance of the pile varies depending on the rate of the load applied to the pile. Therefore, this study seeks to determine the change in lateral resistance of pile foundations according to lateral loading rate through model experiments. The experimental results showed that the lateral resistance of the pile tended to decrease as the lateral loading rate applied to the pile head increased. In order to confirm this, a model experiment of the side change of the ground and pile according to the loading rate was additionally conducted. Through inverse analysis, the change in the depth of the rotation point according to the lateral loading rate was identified. Through the change in the lateral resistance of the pile foundation and the depth of the rotating point according to the lateral loading rate, it was proposed to test the loading rate within 1.5 mm/min during the lateral loading test of the pile.

Lateral Drift Control and Resizing Technique for Tall Buildings using Lateral-Stiffness Influence Matrix (횡강성 영향행렬을 이용한 고층건물의 횡변위 제어 및 단면 재산정 방안)

  • 이한주;김치경;김호수
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.15 no.2
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    • pp.271-279
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    • 2002
  • This study develops the module to find the lateral stiffness influence matrix of each story and performs the displacement sensitivity analysis by virtual load method for the efficiency of optimal design using lateral stiffness influence matrix. Also, resizing technique based on the estimated lateral stiffness increment factors is developed to apply directly the results of optimal design. To this end, resizing technique is divided into the continuous and discrete section design methods. And then the relationships between section properties and section size are established. Specifically, an initial design under strength constraints is first performed, and then the lateral load resistant system is designed to control lateral displacements yet exceeding the drift criteria. Two types of 45-story three dimensional structures we presented to illustrate the features of the lateral drift control and resizing technique for tall buildings proposed in this study.

Usefulness of a Lateral Thoracodorsal Flap after Breast Conserving Surgery in Laterally Located Breast Cancer

  • Yang, Jung Dug;Ryu, Dong Wan;Lee, Jeong Woo;Choi, Kang Young;Chung, Ho Yun;Cho, Byung Chae;Park, Ho Yong;Byun, Jin Suk
    • Archives of Plastic Surgery
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    • v.40 no.4
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    • pp.367-373
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    • 2013
  • Background Breast-conserving surgery is widely accepted as an appropriate method in breast cancer, and the lateral thoracodorsal flap provides a simple, reliable technique, especially when a mass is located in the lateral breast. This study describes the usefulness of a lateral thoracodorsal flap after breast conserving surgery in laterally located breast cancer. Methods From September 2008 to February 2013, a lateral thoracodorsal flap was used in 20 patients with laterally located breast cancer treated at our institution. The technique involves a local medially based, wedge shaped, fasciocutaneous transposition flap from the lateral region of the thoracic area. Overall satisfaction and aesthetic satisfaction surveys were conducted with the patients during a 6-month postoperative follow-up period. Aesthetic results in terms of breast shape and symmetry were evaluated by plastic surgeons. Results The average specimen weight was 76.8 g. The locations of the masses were the upper lateral quadrant (n=15), the lower lateral quadrant (n=2), and the central lateral area (n=3). Complications developed in four of the cases, partial flap necrosis in one, wound dehiscence in one, and fat necrosis in two. The majority of the patients were satisfied with their cosmetic outcomes. Conclusions Partial breast reconstruction using a lateral thoracodorsal flap is well matched with breast color and texture, and the surgery is less aggressive than other techniques with few complications. Therefore, the lateral thoracodorsal flap can be a useful, reliable technique in correcting breast deformity after breast conserving surgery, especially in laterally located breast cancer.

Lateral Damper of Subway Vehicle for Preventing Abnormal Impact (지하철 전동차 비정상 충격 방지를 위한 횡댐퍼에 관한 연구)

  • Shin, Yujeong;You, Wonhee;Park, Joonhyuk;Hur, Hyunmoo;Jeon, Juyun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.1
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    • pp.17-23
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    • 2013
  • In a subway vehicle, a lateral damper is used for compensating the lateral stiffness deterioration due to the air-spring as a secondary suspension. This lateral damper can reduce the lateral vibration of the carbody. When the damping force of the lateral damper is lowered, the running stability and ride quality of the subway vehicles worsens and the lateral motion of the carbody is increased. In this study, the lateral displacement variation of the carbody according to the damping force of the lateral damper was analyzed by multi-body dynamics to solve the abnormal impact problem during vehicle operation. Furthermore, the noise and vibration due to abnormal impact were considered. An adequate damping coefficient of the lateral damper for the subway vehicle treated in this paper was suggested for preventing abnormal impact.

Effect of lateral differential settlement of high-speed railway subgrade on dynamic response of vehicle-track coupling systems

  • Zhang, Keping;Zhang, Xiaohui;Zhou, Shunhua
    • Structural Engineering and Mechanics
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    • v.80 no.5
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    • pp.491-501
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    • 2021
  • A difference in subgrade settlement between two rails of a track manifests as lateral differential subgrade settlement. This settlement causes unsteadiness in the motion of trains passing through the corresponding area. To illustrate the effect of lateral differential subgrade settlement on the dynamic response of a vehicle-track coupling system, a three-dimensional vehicle-track-subgrade coupling model was formulated by combining the vehicle-track dynamics theory and the finite element method. The wheel/rail force, car body acceleration, and derailment factor are chosen as evaluation indices of the system dynamic response. The effects of the amplitude and wavelength of lateral differential subgrade settlement as well as the driving speed of the vehicle are analyzed. The study reveals the following: The dynamic responses of the vehicle-track system generally increase linearly with the driving speed when the train passes through a lateral subgrade settlement area. The wheel/rail force acting on a rail with a large settlement exceeds that on a rail with a small settlement. The dynamic responses of the vehicle-track system increase with the amplitude of the lateral differential subgrade settlement. For a 250-km/h train speed, the proposed maximum amplitude for a lateral differential settlement with a wavelength of 20 m is 10 mm. The dynamic responses of the vehicle-track system decrease with an increase in the wavelength of the lateral differential subgrade settlement. To achieve a good operation quality of a train at a 250-km/h driving speed, the wavelength of a lateral differential subgrade settlement with an amplitude of 20 mm should not be less than 15 m. Monitoring lateral differential settlements should be given more emphasis in routine high-speed railway maintenance and repairs.

The drained deformation characteristics of sand subjected to lateral cyclic loading

  • Junhua Xiao;Jiapei Ma;Jianfeng Xue;Zhiyong Liu;Yingqi Bai
    • Geomechanics and Engineering
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    • v.34 no.5
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    • pp.481-489
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    • 2023
  • Drained cyclic triaxial tests were conducted on a saturated sand to examine its deformation characteristics under either axial or lateral cyclic loading condition. To apply lateral cyclic loading, the cell pressure was cycled while maintaining a constant vertical stress. The strain accumulations and flow direction in the soil were presented and discussed considering various initial stress ratios (η0), cyclic stress amplitudes and cyclic stress paths. The results indicate that axial strain accumulation shows an exponential increase with the maximum stress ratio (ηmax). The initial deviatoric stress has comparable effects with lateral cyclic stress amplitude on the accumulated axial strain. In contrast, the accumulated volumetric strain is directly proportional to the lateral cyclic stress amplitude but not much affected by η0 values. Due to the anisotropy of the soil, the accumulated axial and lateral bulging strains are greater in lateral cyclic loading when compared to axial cyclic loading even though ηmax is the same. It is also found that ηmax affects soil's lateral deformation and increasing the ratio could change the lateral deformation from contraction to bulging. The flow direction depends on ηmax in the sand under lateral cyclic loading, regardless of η0 values and the cyclic stress amplitudes, and a large ηmax could lead to great deviatoric strain but a little volumetric strain accumulation.

Numerical study on the influence of embedment footing and vertical load on lateral load sharing in piled raft foundations

  • Sommart Swasdi;Tanan Chub-Uppakarn;Thanakorn Chompoorat;Worathep Sae-Long
    • Geomechanics and Engineering
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    • v.36 no.6
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    • pp.545-561
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    • 2024
  • Piled raft foundation has become widely used in the recent years because it can increase bearing capacity of foundation with control settlement. The design for a piled raft in terms vertical load and lateral load need to understands contribution load behavior to raft and pile in piled raft foundation system. The load-bearing behavior of the piled raft, especially concerning lateral loads, is highly complex and challenge to analyze. The complex mechanism of piled rafts can be clarified by using three dimensional (3-D) Finite Element Method (FEM). Therefore, this paper focuses on free-standing head pile group, on-ground piled raft, and embedded raft for the piled raft foundation systems. The lateral resistant of piled raft foundation was investigated in terms of relationship between vertical load, lateral load and displacement, as well as the lateral load sharing of the raft. The results show that both vertical load and raft position significantly impact the lateral load capacity of the piled raft, especially when the vertical load increases and the raft embeds into the soil. On the same condition of vertical settlement and lateral displacement, piled raft experiences a substantial demonstrates a higher capacity for lateral load sharing compared to the on-ground raft. Ultimately, regarding design considerations, the piled raft can reliably support lateral loads while exhibiting behavior within the elastic range, in which it is safe to use.