• 한국자동차공학회논문집
• /
• 제16권5호
• /
• pp.77-83
• /
• 2008

Semi-active cabin air suspension system improves driver's comfort by controlling the damping characteristics in accordance with driving situation. For the driver's comfort evaluation, test procedure has the two methodologies which are filed test and lab test. A field test method has a drawback. It requires a lot of time and money on repetitive test, due to the sensitivity of field test. On the other hand, the test with six axes simulation table at laboratory can obtain the repeatability of test, better than the field test method. In this paper, the procedures of ride performance test and control logic tuning with the table are presented. Drive files of the table can be represented with the almost same input condition as field test data. According to the result from the comparative test using six axes simulation table between passive and semi-active system by making ECU logic tuning, the RMS acceleration of semi-active cabin air suspension system was reduced by 29.6% compared with passive system.

• KIEAE Journal
• /
• 제16권3호
• /
• pp.5-12
• /
• 2016

Purpose: In case of existing building, A lot of attempts are being made like changing thermal system or using high efficiency products to decrease energy load and increase energy efficiency. However, (1) Absence of systemed database of green-remodeling technology and products. (2) Absence of comparative analysis system and qualitative/quantitative evaluation method of energy performance and energy reduction cost. (3) Existing remodeling was very hard to access for non-experts. So, in this paper, the authors developed data base for green-remodeling(Impact Table A, Impact Table B) and optimum combination dedication tool for user convenience. Accordingly, purpose of this paper validate usefulness of Impact Table and optimum alternative dedication tool. Method: For validate the usefulness of Impact Table and optimum combination dedication tool, the authors selected five test model office buildings. Next, through research investigation, the authors diagnosed the present state of buildings. In base of diagnosis results, select technologies for remodeling by qualitative comparison (Impact Table A). Next, evaluate quantitative price and performance technologies that selected in Impact Table A (Impact Table B). Lastly, through final evaluation of Impact Taba A and Impact Table B, determine the direction of the green-remodeling. Result: Impact Table and optimum combination dedication tool can use relative indicator for green-remodeling, especially through ROI by detail field.

• 한국정밀공학회지
• /
• 제27권7호
• /
• pp.94-100
• /
• 2010

This paper describes the design and evaluation procedure of an ultra-precision rotary table for freeform generating machined tools. Design of the thrust and journal hydrostatic bearings and experimental evaluation of the table were performed. To get the compact size and less lost motion direct drive servomotor with ultra precision encoder. From the considered design, following performance were confirmed by experiment. The total stiffness of the prototype rotary table was 483.6 $N/{\mu}m$ and 97.6 $N/{\mu}m$ for axial and radial direction, respectively. Rotational accuracy of the table was investigated by capacitive sensor and reversal measurement technique, and 0.10 ${\mu}m$ radial direction and 0.05 ${\mu}m$ axial direction of the rotational accuracy were confirmed. The micro resolution of the table was also investigated with displacement of capacitive sensor, and $0.5/10000^{\circ}$ of micro resolution was confirmed. Index accuracy of the table was evaluated by the autocollimator and polygon mirror, and the $\pm0.39$ arcsec accuracy and $\pm0.16$ arcsec repeatability of the table were confirmed. Those are under the general requirements of ultra precision rotary tables for freeform generating machined tools.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 추계학술대회논문집
• /
• pp.669-673
• /
• 2007

In this study, real-time hybrid test using a shaking table for the control performance evaluation of a U-shaped TLCD controlling the response of earthquake-excited building structure is experimentally implemented. In the test, the building structure is used as a numerical part, on which a U-shaped TLCD adopted as an experimental part was installed to reduceits response. At first, the force that is acting between a TLCD and building structure is measured from the load cell attached on shaking table and is fed-back to the computer to control the motion of shaking table. Then, the shaking table is so driven that the error between the interface acceleration computed from the numerical building structure with the excitations of earthquake and the fed-back interface force and that measured from the shaking table. The control efficiency of the TLCD used in this paper is experimentally confirmed by implementing this process of shaking table experiment on real-time.

• 콘크리트학회논문집
• /
• 제18권6호
• /
• pp.721-728
• /
• 2006

지진은 구조물에 막대한 피해를 발생시키는 것으로 보고되고 있으나, 우리나라에 내진설계규정이 도입되기 전인 1988년 이전에 설계된 건물은 이에 대한 대책이 없다. 특히 공동주택의 경우 지진저항요소가 없는 구조물이 다수 있는 것으로 조사되었다. 이러한 구조물에 대하여 내진성능의 정도를 파악하고, 성능지수가 부족한 구조물에 대해서는 적절한 보강이 이루어져야 할 것이다. 본 연구에서는 이전의 연구에서 범용 구조해석 프로그램인 MIDAS를 이용하여 모델 구조물의 내진성능을 평가하여 얻어진 내진성능의 부족함을 기초로 5층 규모의 철근콘크리트 벽식 구조물에 상사법칙을 적용하고, 진동대 실험을 수행하여 국내외 규준에 의한 모델 구조물의 내진성능을 평가하였다. 진동대 실험의 경우 실험의 공간적 제약으로 인하여 원형 구조물에 대한 실험을 할 수 없어, 구조물의 원형크기를 상사법칙에 의하여 필요한 규모로 축소하여 제작하였다. 성능수준을 평가해 본 결과 내진설계가 수행되지 않은 구조물은 PGA 등급 0.2g의 지진에 대하여 사용한계수준의 내진성능을 나타내었으며 허용층간변위를 평가해 본 결과 0.2g의 지진등급까지만 허용한계수준의 층간변위를 나타내어 내진성능에 대한 보강이 필요할 것으로 판단되었다.

• 한국정밀공학회지
• /
• 제31권7호
• /
• pp.635-642
• /
• 2014

The large volume multi-tasking vertical lathe was developed for machining the bearing parts for a wind power generator. Although the machined part is large in size high precision tolerances are required recently. One of the most important components to achieve this mission is the rotating table which holds and supports the part to be machined. The oil hydrostatic bearing is adopted for the thrust bearing and the rolling bearing for the radial bearing. In this article experimental performance evaluation and its analysis results are presented. The rotational accuracy of the table is assessed and the frequency domain analysis for the structural loop is performed. And in order to evaluate the structural characteristic of table the moment load experiment is performed. The rotational error motion is measured as below 10 ${\mu}m$ for the radial and axial direction and 22,800 Nm/arcsec of moment stiffness is achieved for the rotary table.

• 국제초고층학회논문집
• /
• 제1권3호
• /
• pp.221-228
• /
• 2012

Shanghai Tower is a super high-rise building of 632 m height with 'mega frame-core- outrigger truss' structure system. Due to the complexity and irregularity of structure, shaking table test was carried out to investigate its seismic performance. A 1/40 scaled test model was designed, built and tested on shaking table under earthquake of small, moderate and large levels. The experimental results showed that the structure can meet the requirements of Chinese codes and reach scheduled performance objectives. Elastic and plastic time-history analysis on the structure were carried out and the results were compared to experimental results. Based on the research results some suggestions were proposed to contribute favorable effect on the seismic capacity of the structure.

• Nuclear Engineering and Technology
• /
• 제55권9호
• /
• pp.3342-3351
• /
• 2023

High-density polyethylene (HDPE) pipelines in nuclear power plants (NPPs) have to meet high requirements for seismic performance. HDPE pipes have been proved to have good seismic performance, but joints are the weak links in the pipelines, and pipeline failures usually initiate from the defects inside the joints. Limited data are available on the seismic performance of butt-fusion joints of HDPE pipelines in NPPs, especially in terms of defects changes inside the joints after earthquakes. In this paper, full-scale shaking table tests were performed on a test section of suspended HDPE pipelines in an NPP, which included straight pipes, elbows, and 10 butt-fusion joints. During the tests, the seismic load-induced strain of the joints was analyzed by strain gauges, and it was much smaller than the internal pressure and self-weight-induced strain. Before and after the shaking table tests, phased array ultrasonic testing (PA-UT) was conducted to detect defects inside the joints. The locations, numbers, and dimensions of the defects were analyzed. It was found that defects were more likely to occur in elbows joints. No new defect was observed after the shaking table tests, and the defects showed no significant growth, indicating the satisfactory seismic performance of the butt-fusion joints.

• 한국생산제조학회지
• /
• 제21권2호
• /
• pp.208-213
• /
• 2012

In this paper, the radial error of a rotary table at five-axis machine tool is evaluated by utilizing ISO 230-2 and estimation method using double ball-bar. The geometric error of a rotary table is defined as position dependent geometric errors or position independent geometric errors according to their physical character. Then estimation method of geometric errors using double ball-bar is simply summarized including measurement path, parametric modeling and least squares approach. To estimate representative radial error, offset error, set-up error which affect to the double ball-bar data, mean value of measured data including CCW/CW-direction are used at estimation process. Radial errors are separated from measured data and used for evaluation with ISO 230-2. Finally, suggested evaluation method is applied to a rotary table at five-axis machine tool and its result is analyzed to improve the accuracy of the rotary table.

• 대한건축학회논문집:구조계
• /
• 제35권10호
• /
• pp.171-180
• /
• 2019

In Korea, the seismic design of non-structural elements was interested by Earthquake of the 2016 Gyeong-ju and 2017 Po-hang. Among the non-structural elements, the ceiling system with steel panel used in Po-hang station showed failure examples of non-seismic design ceiling. In this study, the seismic performance of suspended ceiling with steel-panel, such as those used in Po-hang Station, was evaluated by shaking table tests. The shaking table tests were performed in accordance with the ICC-ES AC156 standard with floor acceleration being applied horizontally in one direction using a $3.3{\times}3.3m^2$ frame. The ceiling system consists of steel-panels, carrying channels, main and cross T-bars, and anti-falling clips. The anti-falling clip prevents the steel panel falling completely. The shaking table test confirmed that the damage at the previous stage had a direct impact on the damage state at the next stage. Through the shaking table test, the damage state of the T-bar type steel-panel suspended ceiling system was defined.