차량의 종류에 따른 교량의 충격계수 해석

정태주 한라대학교 2006 論文集 Vol.9 No.-

In this paper, effects of vehicle types on dynamic impact factor of bridge is carried out Heavy trucks with 2-axles, 3-axles and 5-axles are modeled by 7-d of , 8-d of and l4-d of , in which contact length of tire and pitching of tandem spring axles is considered Dynamic equations of vehicle are derived by using the Lagrange's equation and solution of equation is calculated by Newmark-β method The validity of developed 3-D vehicle model is demonstrated by comparing the results obtained by present method and experimental data by Whittimore And the validity of the proposed procedure is demonstrated by comparing the results with the experimental data reported by the AASHO Road Test In the calculation of the dynamic impact factor, simple span plate-girder bridges with span length of 30m and simple span prestressed concrete beam bridges with span length of 20m are considered

차종에 따른 지방도 소규모 도로교의 동적응답

정태주 한국강구조학회 2019 韓國鋼構造學會 論文集 Vol.31 No.5

In this study, the dynamic responses of short-span bridges on local road are investigated by numerical analysis considering road surface roughness of bridge and bridge-vehicle interaction. Simply supported of RC slab bridges with span length of 8 m, 10 m and 12 m are used for bridge model, settlements of approach slab are considered in the analysis, and the road surface roughness of bridge are generated from power spectral density (PSD) function for poor road. Three different vehicles of 4-axle dump truck and 5-axle tractor-trailer (DB-24 and KL-510) are used for 3-D. vehicle model. The impact factors and dynamic load allowance (DLA) of RC slab bridges for different spans, type of vehicles, settlements of approach slab and road surface roughness for poor road are calculated by the proposed numerical analysis and compared with those specified by several bridge design codes. 본 연구에서는 노면조도 및 교량과 차량의 사이의 상호작용작용을 고려한 수치해석방법에 의한 지방도 소규모 도로교의 동적응답을 연구하였다. 대상교량은 8 m, 10 m와 12 m 지간의 단순 RC슬래브교를 사용하고, 교량 진입부의 단차를 고려하였으며, “불량한 도로”에 대하여 생성시킨 10개의 노면조도를 사용하였다. 대상차량은 4축 24톤 덤프트럭, 5축 트랙터-트레일러인 DB-24와 KL-510 을 3차원 차량모델로 모델링하였다. 이와 같은 차량, 교량 진입부의 단차와 노면조도를 사용하여 단순 RC슬래브교의 지간별, 차종별, 단차 및 노면조도에 따른 충격계수와 DLA를 구하고 각국의 설계기준과 비교하였다.

교량 신축이음장치 부근의 동적하중허용계수

정태주 한라대학교 2007 論文集 Vol.10 No.-

In this paper, numerical analysis method to perform linear dynamic analysis of bridge considering the road surface roughness when vehicle is moving on bridge is presented. The vehicle is modeled as three-dimension where contact length of tire and pitching of tandem spring are considered and single truck with 2-axles and 3-axles, and tractor-trailer with 5-axles are modeled as 7-D.O.F., 8-D.O.F., and 14-D.O.F., respectively. Dynamic equations of vehicle are derived from the Lagrange's equation and solution of the equation is obtained by Newmark-β method. The proposed procedure is validated by comparing the results with the experimental data by Whittemore. And the dynamic characteristics when a vehicle passes the expansion joint in which the severe road surface irregularities are often observed are also investigated by observing the tire force calculated before and after passing the expansion joint. Based on the resulting statistical parameters, the DLA of bridge including near expansion joints is calibrated.

3차원(次元) 차량(車輛)모델을 사용(使用)한 강도로교(鋼道路橋)의 동적응답(動的應答) 관(關)한 연구(硏究)

정태주,박영석,Chung, Tae Ju,Park, Young Suk 대한토목학회 1994 대한토목학회논문집 Vol.14 No.5

본 연구에서는 교량과 차량을 3차원으로 모델링하고, 교량의 노면조도 및 교량과 차량 사이의 상호작용력을 고려하여 이동차량이 교량올 통과할 때 교량의 선형 동적해석을 수행할 수 있는 해석방법을 제시하였다. 교량의 노면조도는 평균값이 영인 정상확율분포로 가정한 지수 스팩트럴 밀도(PSD)를 사용하여 생성시켰다. 이 때 지수 스팩트럴 밀도는 양호한 도로에 대하여 C.J. Dodds와 J.D. Robson이 제안한 PSD값을 사용하였다. 차량은 트럭과 트랙터-트레일러를 각각 7-자유도와 12-자유도를 갖는 3차원차량으로 모델링하였고, 차량의 운동방정식은 Lagrange 방정식을 사용하여 유도하였다. 교량은 주형을 보요소로 이상화시키고 콘크리트 바닥판을 쉘요소로 이상화시켰으며 주형과 콘크리트 바닥판을 Rigid Link로 연결하여 3차원으로 모델링하였다. 차량의 운동방정식은 Newmark ${\beta}$법을 사용하고 교량의 운동방정식은 모우드 중첩법을 사용하여 풀었다. 본 연구에서 제시한 해석방법의 타당성을 검토하기 위하여 "AASHO Road Test"에서 실시한 단순 강합성교의 실험결과와 본 연구에서 제시한 해석적인 방법으로 구한 값을 비교하였다. 해석 결과, 본 연구에서 제시한 해석적인 방법으로 구한 값과 실험값이 매우 잘 일치하였다. This paper is presented to perform linear dynamic analysis of bridges due to vehicle moving on bridges. The road surface roughness and bridge/vehicle interaction are also considered. The bridge and vehicle are modeled as 3-D bridge and vehicle model, respectively. The road surface roughness of the roadway and bridge decks are generated from power spectral density(PSD) function for good road. The PSD function proposed by C.J. Dodds and J.D. Robson is used to describe the road surface roughness for good road condition. The vehicles are modeled as two nonlinear vehicle model with 7-D.O.F of truck and 12-D.O.F of tractor-trailer and the equations of motion of the vehicles are derived using Lagrange's equation. The main girder and concrete deck are modeled as beam and shell element, respectively and rigid link is used between main girder and concrete deck. The equations of motion of the vehicles are solved by Newmark ${\beta}$ method and the equations of the motion of the bridges are solved by mode-superposition procedures. The validity of the proposed procedure is demonstrated by comparing the results with the experimental data reported by the AASHO Road Test. The comparison shows that the agreement between experiment and theory is quite satisfactory.

WC 첨가 방법에 따른 Ti(CN)-Co/Ni 계 서멧트의 미세조직 및 특성변화

정태주,안선용,안승수,신명수,김학규,김경배,오경식,이혁재,Chung, Tai-Joo,Ahn, Sun-Yong,Ahn, Seung-Su,Shin, Myung-Soo,Kim, Hak-Kyu,Kim, Kyung-Bae,Oh, Kyung-Sik,Lee, Hyuk-Jae 한국분말야금학회 2007 한국분말재료학회지 (KPMI) Vol.14 No.2

In the Ti(CN)-Co/Ni cermet, WC is an effective additive for increasing sinterability and mechanical properties such as toughness and hardness. In this work, WC, (WTi)C and (WTi)(CN) were used as the source of WC and their effects were investigated in the respect of microstructural evolution and mechanical properties. Regardless of the kinds of WC sources, the hard phase with dark core and bright rim structure was observed in the Ti(CN)-Co/Ni cermet under the incorporation of relatively small amount of WC. However, hard phases with bright core began to appear and their frequency increased with the increase of all kinds of WC source addition. The ratio of bright core to dark one in the (TiW)(CN)-Co/Ni cermet was greatest under the incorporation of (WTi)C compared at the same equivalent amount of WC. The mechanical properties were improved with the addition of WC irrespective of the kinds of sources, but the addition of (WTi)(CN) was less effective for the increase of fracture toughness.

WC와 Co원료 입자크기 변화에 따른 WC-Co계 초경합금의 특성 변화

정태주,안선용,백용균,Chung, Tai-Joo,Ahn, Sun-Yong,Paek, Yeong-Kyeun 한국세라믹학회 2005 한국세라믹학회지 Vol.42 No.3

서로 다른 입자크기를 갖는 WC와 Co 분말 원료를 사용하여 $WC-10\;wt\%$Co 초경합금을 제조하였다. 이로부터 WC와 Co 원로. 입자크기가 제조된 초경합금의 성질에 미치는 영향에 대해 고찰하였다. WC 원료 입자크기가 클수록 제조된 초경합금이 파괴인성이 높고 경도는 낮게 나타나는데, 이러한 경향은 Co 원료 입자크기에 크게 영향 받지 않음을 알 수 있었다. Co 원료 크기의 영향 외에도 Co 원료 크기가 초경합금의 특성에 영향을 주는 것으로 밝혀졌는데, 동일한 WC 원료를 사용하여도 미세한 Co 원료를 사용할 경우, 보다 조대한 WC를 함유하여 인성이 우수한 초경합금을 제조할 수 있었다. 이로부터 Co 원료 입자크기가 초경합금의 미세구조 및 그 특성에 중요한 역할을 함을 알 수 있었다 The effect of variation in particle size of WC and Co powder on the properties of WC-Co alloys was investigated. WC and Co powders having different particle sizes were used in the fabrication of $WC-10\;wt\%$Co composites. High hardness and low fracture toughness alloy was obtained with the decrease in WC particle size regardless of Co particle size. It was newly found in this investigation that the initial particle size of Co as well as WC had a great role in the microstructure and properties of WC-Co hard materials. The average grain size and fracture toughness of WC-Co alloys using same WC powder size increased and their hardness decreased with the use of relatively finer Co binder.

Y-TZP에서 표면 처리에 따른 저온열화 거동의 직접적 관찰

정태주,김혜성,Chung, Tai-Joo,Kim, Hye-Sung 한국분말야금학회 2010 한국분말재료학회지 (KPMI) Vol.17 No.3

Low temperature degradation behavior in yttria stabilized tetragonal zirconia polycrystal (Y-TZP) ceramics was microscopically observed from the phase contrast between monoclinic surface and tetragonal matrix. The degradation behavior was dependent on the surface treatment of sintered Y-TZP, even if the sintering history is same. In the mirror polished specimen, the monoclinic layer appeared in a uniform thickness from the surface. On the contrary, for the specimen with coarse scratch, the thickness of degraded surface was more than double especially from the coarse scratch. Since the scratch results in local deformation, the residual stress should be induced around the scratch. With the transformation from tetragonal to monoclinic, the volume expansion exerts a stress on a neighboring grains and promotes a successive phase transformation. Such a autocatalytic effect can be triggered from the part of coarse scratch.

KL-510 하중에 의한 강판형교의 동적응답

정태주 한국구조물진단유지관리공학회 2013 한국구조물진단유지관리공학회 논문집 Vol.17 No.6

본 연구에서는 교량의 노면조도 및 교량과 차량 사이의 상호작용을 고려한 수치해석방법을 사용하여 도로교설계기준에 규정된 표준트럭 하중인 KL-510에 의한 강판형교의 동적응답을 연구하였다. 대상교량은 건설부에서 제정한 “도로교 상부구조 표준도”에 수록되어 있는 지간이 20m, 30m와 40m인 단순 강판형교를 사용하고. “보통의 도로”에 대하여 생성시킨 10개의 노면조도를 사용하였다. 차량은 5축 트랙터-트레일러인 표준트럭하중 KL-510을 3차원 차량으로 모델링하고, 교량은 주형을 보요소로, 콘크리트 바닥판은 쉘요소로, 주형과 콘크리트 바닥판 사이는 Rigid Link를 사용하여 3차원으로 모델링하였다. 이와 같은 노면조도 및 차량을 사용하여 강판형교의 충격계수와 DLA를 구하고 각국의 설계기준과 비교 검토하였다. Dynamic response of steel plate girder bridges by KL-510 design truck in KHBDC considering the road surface roughness of bridges and bridge-vehicle interaction is investigated. Simply supported steel plate girder bridges with span length of 20m, 30m, and 40m from “Standard Highway Bridge Superstructure” published by the Korean Ministry of Construction are used for a bridge model, and ten sets of the road surface roughness of bridge deck are generated from power spectral density (PSD) function by assuming the roadway as “Average Road”. A three dimensionally modeled 5-axle tractor-trailer with its gross weight, which is the same as that of KL-510 design truck, is used for dynamic analysis. For the finite element modeling of superstructure, beam element for the main girder, shell element for the concrete deck, and rigid link between main girder and concrete deck are used. Impact factor and DLA of steel plate girder bridges for different span are calculated by the proposed numerical analysis model and compared with those specified by several bridge codes.

鋼橋의 疲勞損傷 事例 硏究

鄭泰周,朴英錫 명지대학교 공학기술연구소 1991 공학기술연구소 논문집 Vol.6 No.-

A number of highway and railroad girders in foreign countries have experienced fatigue cracking and many researches on the fatigue damages have been made for many years. But we have few case studies and tests for fatigue damages in those bridges. This paper represents many types of cracks developed in bridge structures in Japan, the reasons for their occurrence and retrofitting and rehabilitating methods for those damages. The individual case of this paper will provide valuable insight into causes of cracking and the significance of structural details.

[위원회 소식] 강원지회 소식/광주·전남지회 소식

정태주,강성후 대한토목학회 2016 대한토목학회지 Vol.64 No.11