• Title, Summary, Keyword: lateral stiffness

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Experimental study on shear damage and lateral stiffness of transfer column in SRC-RC hybrid structure

  • Wu, Kai;Zhai, Jiangpeng;Xue, Jianyang;Xu, Fangyuan;Zhao, Hongtie
    • Computers and Concrete
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    • v.23 no.5
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    • pp.335-349
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    • 2019
  • A low-cycle loading experiment of 16 transfer column specimens was conducted to study the influence of parameters, likes the extension length of shape steel, the ratio of shape steel, the axial compression ratio and the volumetric ratio of stirrups, on the shear distribution between steel and concrete, the concrete damage state and the degradation of lateral stiffness. Shear force of shape steel reacted at the core area of concrete section and led to tension effect which accelerated the damage of concrete. At the same time, the damage of concrete diminished its shear capacity and resulted in the shear enlargement of shape steel. The interplay between concrete damage and shear force of shape steel ultimately made for the failures of transfer columns. With the increase of extension length, the lateral stiffness first increases and then decreases, but the stiffness degradation gets faster; With the increase of steel ratio, the lateral stiffness remains the same, but the degradation gets faster; With the increase of the axial compression ratio, the lateral stiffness increases, and the degradation is more significant. Using more stirrups can effectively restrain the development of cracks and increase the lateral stiffness at the yielding point. Also, a formula for calculating the yielding lateral stiffness is obtained by a regression analysis of the test data.

Identifying stiffness irregularity in buildings using fundamental lateral mode shape

  • Vijayanarayanan, A.R.;Goswami, Rupen;Murty, C.V.R.
    • Earthquakes and Structures
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    • v.12 no.4
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    • pp.437-448
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    • 2017
  • Soft or extreme soft storeys in multi-storied buildings cause localized damage (and even collapse) during strong earthquake shaking. The presence of such soft or extremely soft storey is identified through provisions of vertical stiffness irregularity in seismic design codes. Identification of the irregularity in a building requires estimation of lateral translational stiffness of each storey. Estimation of lateral translational stiffness can be an arduous task. A simple procedure is presented to estimate storey stiffness using only properties of fundamental lateral translational mode of oscillation (namely natural period and associated mode shape), which are readily available to designers at the end of analysis stage. In addition, simplified analytical expressions are provided towards identifying stiffness irregularity. Results of linear elastic time-history analyses indicate that the proposed procedure captures the irregularity in storey stiffness in both low- and mid-rise buildings.

Analysis on the Lateral Stiffness of Coil Spring for Railway Vehicle (철도차량용 코일스프링 횡강성 해석)

  • Hur, Hyun-Moo;Ahn, Da-Hoon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.9
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    • pp.84-90
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    • 2018
  • In constructing the multi-body dynamics model to analyze the behavior of the railway vehicle, it is very important to understand the properties of the suspension elements that constitute the suspension system. Among them, coil springs, which are mainly used in primary and secondary suspension systems, clearly show the axial stiffness in the drawings, but the lateral properties of the coil springs are not specified clearly, making it difficult to construct a dynamic analysis model. Therefore, in this paper, the model for analyzing the lateral stiffness of the coil spring is examined. A finite element method was applied to analyze the lateral stiffness of the coil spring and numerical analysis was performed by applying the coil spring lateral stiffness analysis model proposed by Krettek and Sobczak. And the test to analyze the lateral stiffness of coil spring was conducted. As a result of comparing with the test results, it was found that the results obtained by applying the lateral stiffness analysis model of Krettek and Sobczak and correcting the correction coefficient are similar to those of the test results.

A Study on the H-typed Railway Sleeper (H형 침목에 관한 연구)

  • Bae, Hyun-Ung;Bae, Sang-Won;Kim, Hae-Gon;Lee, Chin-Ok;Lim, Nam-Hyoung
    • Proceedings of the KSR Conference
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    • pp.680-683
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    • 2010
  • The lateral stiffness of the track structure is very important mechanical property to prevent the track buckling and progress of misalignment. The increasing methods of the lateral stiffness of the track structure are the following; increases of the lateral ballast resistance, and increases of the lateral stiffness of the track panel. In order to increase the lateral stiffness of the tack panel, some of the sleepers resist together against the lateral movement can be the most economical and mechanical method. In this paper, H-typed sleeper developed to solve this problem is introduced and the mechanical advantages of this sleeper are investigated.

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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.

Effect of Contact Stiffness on Lateral Force Calibration of Atomic Force Microscopy Cantilever (원자 현미경 탐침의 수평방향 힘 교정에 미치는 접촉 강성의 영향)

  • Tran, Da Khoa;Jeon, Ki-Joon;Chung, Koo-Hyun
    • Tribology and Lubricants
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    • v.28 no.6
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    • pp.289-296
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    • 2012
  • Atomic force microscopy (AFM) has been used for imaging surfaces and measuring surface forces at the nano-scale. Force calibration is important for the quantitative measurement of forces at the nano-scale using AFM. Normal force calibration is relatively straightforward, whereas the lateral force calibration is more complicated since the lateral stiffness of the cantilever is often comparable to the contact stiffness. In this work, the lateral force calibrations of the rectangular cantilever were performed using torsional Sader's method, thermal noise method, and wedge calibration method. The lateral optical lever sensitivity for the thermal noise method was determined from the friction loop under various normal forces as well. Experimental results showed that the discrepancies among the results of the different methods were as large as 30% due to the effect of the contact stiffness on the lateral force calibration of the cantilever used in this work. After correction for the effect of contact stiffness, all the calibration results agreed with each other, within experimental uncertainties.

Resection Arthroplasty for the Treatment of Joint Stiffness after Dislocation of the Four Lateral Lesser Metatarsophalangeal Joints (A Case Report) (4개의 외측 소족지 중족 족지 관절의 탈구 후 발생한 관절의 강직에서 시행한 절제 관절 성형술(1예 보고))

  • Park, Chul-Hyun;Lee, Woo-Chun
    • Journal of Korean Foot and Ankle Society
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    • v.16 no.1
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    • pp.58-61
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    • 2012
  • Motion of the metatarsophalangeal joints is essential for the normal gait. Therefore it is important to recover the motion of normal joint in the treatment of stiffness of the metatarsophalangeal joints. However, there have been no report about the treatment of stiffness of the four lateral lesser metatarsophalangeal joints yet. We report an experience that good clinical and radiographic results were obtained after resection arthroplasty for the post-traumatic stiffness of the four lateral lesser metatarsophalangeal joints.

Design, Fabrication and Characterization of Lateral PZT actuator using Stiffness Control (강성제어 구조물을 이용한 수평구동형 박막 PZT 엑츄에이터의 설계, 제작 및 특성평가)

  • 서영호;최두선;이준형;이택민;제태진;황경현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.756-759
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    • 2004
  • We present a piezoelectric actuator using stiffness control and stroke amplification mechanism in order to make large lateral displacement. In this work, we suggest stiffness control approach that generates lateral displacement by increasing the vertical stiffness and reducing the lateral stiffness using additional structure. In addition, an additional structure of a serpentine spring amplifies the lateral displacement like leverage structure. The suggested lateral PZT actuator (bellows actuator) consists of serpentine spring and PZT/electrode layer which is located at the edge of the serpentine spring. The edge of the serpentine spring prevents the vertical motion of PZT layer, while the other edge of the serpentine spring makes stroke amplification like leverage structure. We have determined dimensions of the bellows actuator using ANSYS simulation. Length, width and thickness of PZT layer are 135$\mu$m, 20$\mu$m and 0.4$\mu$m, respectively. Dimensions of the silicon serpentine spring are thickness of 25$\mu$m, length of 300$\mu$m, and width of 5$\mu$m. The bellows actuator has been fabricated by SOI wafer with 25$\mu$m-top silicon and 1$\mu$m-buried oxide layer. The bellows actuator shows the maximum 3.93$\pm$0.2$\mu$m lateral displacement at 16V with 1Hz sinusoidal voltage input. In the frequency response test, the fabricated bellows actuator showed consistent displacement from 1Hz to 1kHz at 10V. From experimental study, we found the bellows actuator using thin film PZT and silicon serpentine spring generated mainly laterally displacement not vertical displacement at 16V, and serpentine spring played role of stroke amplification.

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Seismic performance of lateral load resisting systems

  • Subramanian, K.;Velayutham, M.
    • Structural Engineering and Mechanics
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    • v.51 no.3
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    • pp.487-502
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    • 2014
  • In buildings structures, the flexural stiffness reduction of beams and columns due to concrete cracking plays an important role in the nonlinear load-deformation response of reinforced concrete structures under service loads. Most Seismic Design Codes do not precise effective stiffness to be used in seismic analysis for structures of reinforced concrete elements, therefore uncracked section properties are usually considered in computing structural stiffness. But, uncracked stiffness will never be fully recovered during or after seismic response. In the present study, the effect of concrete cracking on the lateral response of structure has been taken into account. Totally 120 cases of 3 Dimensional Dynamic Analysis which considers the real and accidental torsional effects are performed using ETABS to determine the effective structural system across the height, which ensures the performance and the economic dimensions that achieve the saving in concrete and steel amounts thus achieve lower cost. The result findings exhibits that the dual system was the most efficient lateral load resisting system based on deflection criterion, as they yielded the least values of lateral displacements and inter-storey drifts. The shear wall system was the most economical lateral load resisting compared to moment resisting frame and dual system but they yielded the large values of lateral displacements in top storeys. Wall systems executes tremendous stiffness at the lower levels of the building, while moment frames typically restrain considerable deformations and provide significant energy dissipation under inelastic deformations at the upper levels. Cracking found to be more impact over moment resisting frames compared to the Shear wall systems. The behavior of various lateral load resisting systems with respect to time period, mode shapes, storey drift etc. are discussed in detail.

The Experimental Study on the Correlation of the Interior Noise of a Driving Vehicle with Lateral Dynamic Stiffness of the Wheel (주행 중 실내소음과 Wheel의 Lateral Dynamic Stiffness와의 상관관계에 대한 시험적 연구)

  • Kim, Byung-Jin;Sa, Jung-Hwan;Park, Jin-Sung;Park, Hyun-Woo;Cho, Seong-Keun;Jeong, Heon Sul
    • Transactions of the KSME C: Technology and Innovation
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    • v.2 no.1
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    • pp.9-13
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    • 2014
  • Nowadays, among several reasons for customers to choose their own cars, NVH performance plays much important role. The concern for the car interior noise is increasing recently, because electric cars and hybrid cars generate less engine noise which was the main noise of traditional cars. According to oversea references, high Lateral Dynamic Stiffness (LDS) of vehicle wheels is described to reduce Structure Bone Noise (SBN) which is being generated while driving cars. However availablet test standards and test results are not enough, in this study the interior noise has been measured after attaching a same tyre to several wheels which has different Lateral Dynamic Stiffness. The test has verified that the interior noise differs depending on Lateral Dynamic Stiffness of wheels. As to this, the reduction of the interior noise can be possible with the optimal design of the wheel.