• 한국정밀공학회지
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• 제28권8호
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• pp.894-903
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• 2011

In this paper, the capability index is introduced in order to improve the reliability of new concept machine tools and the method to improve the machine accuracy from the analysis of cutting process, statistical methodology and influence factors are proposed. In addition, the rib structure of bed and column in machine tools is analyzed by using the thermal impact method in order to analogize the rib pattern which has the small thermal deformation under thermal boundary condition. In the analysis of column rib structure, thermal boundary condition is separated to heat conduction and heat transfer to appropriate real boundary condition. Finally, performance chart of bed and column rib structure is provided for designer to estimate each rib pattern and select rib structure appropriating to thermal condition.

• 한국강구조학회 논문집
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• 제10권2호통권35호
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• pp.291-301
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• 1998

종리브로 보강된 충전형 원형강관에 H형강보를 사용한 접합부 모델실험 결과와 항복선이론 및 수치해석을 이용하여 접합부 국부내력의 추정을 위한 기초 자료를 제시하고 궁극적으로는 원형강관 접합부의 보강법을 연구하여 다이아프램이 없는 콘크리트 충전강관 기둥-H형강보 접합부의 개발을 위한 기초자료를 제시하고자 한다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 추계학술대회 논문집
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• pp.361-362
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.813-814
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• 2011

• 한국생산제조학회지
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• 제19권6호
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• pp.746-752
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• 2010

Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

• 한국소음진동공학회논문집
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• 제17권3호
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• pp.213-219
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• 2007

Column mixer Is one of the facilities to mix fluids at petrochemical plants. The vibration of column mixer is usually caused by pumps for fluid inflow and mixing of inside fluids. This fluid induced nitration is mainly responsible for the reduction of column life. Measurements were performed for understanding the vibration characteristics of the column. First measurement results showed the need of stiffness reinforcement. After the reinforcement work, second measurement confirmed the difference between two results. Modal analysis was also performed to investigate the resonance of the column vibration and the damage of the rib plate. To confirm fluid induced vibration at the column mixer fluid structure interaction analysis using ADINA/FSI was performed, which showed the necessity of the modification of the rotary valve.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.916-921
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• 2006

Column mixer is one of the facility to mix fluids at petrochemical plants. The column vibration is caused by pumps for fluid inflow and mixing of inside fluids. This fluid induced vibration is mainly responsible for the reduction of column life. Measurements were performed three times for understanding the vibration characteristics of the column. First experimental results showed the need of stiffness reinforcement. After the reinforcement work, second measurement conformed the difference between two results. Modal analysis was also performed to investigate the resonance of the column vibration and the damage of the rib plate. To confirm the generation of the fluid instability in the column mixer fluid structure interaction analysis using ADINA/FSI was performed which showed the necessity of the modification of the rotary valve.

• 한국강구조학회 논문집
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• 제28권2호
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• pp.121-128
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• 2016

고장력 볼트를 적용한 원형단면 콘크리트 충전 강재 기둥-기초 연결부의 합리적인 설계범위를 제안하기 위하여 축하중과 수평하중을 동시에 받는 기둥-기초 연결부의 전반적인 구조적 거동과 설계변수에 따른 거동특성을 상용 유한요소해석 프로그램인 ABAQUS를 이용하여 해석적으로 검토하였다. 이를 위해 앵커볼트를 고장력 볼트로 대신하는 선행연구의 실험을 토대로 수치해석을 실시하였으며, 해석방법의 타당성을 검증하였다. 또한 현행 설계기준을 분석하여 기둥-기초 연결부 거동에 영향을 미치는 설계변수(앵커의 묻힘깊이, 앵커의 강종, 리브의 높이, 리브의 두께)를 선정하였으며, 설계변수에 따른 기둥-기초 연결부의 거동특성을 비교 분석하였다. 일반 앵커에 비해 고장력 볼트를 적용하는 것이 기둥-기초 연결부의 거동에 유리한 것으로 나타났으며, 고장력 볼트의 최소 묻힘깊이는 기둥 직경(D)을 기준으로 0.5D이상으로 설계하는 것이 합리적이라고 판단된다. 리브의 높이는 0.5D이상, 리브의 두께는 베이스플레이트 두께($t_b$)를 기준으로 $0.4t_b$이상으로 설계하는 것이 합리적이라고 판단된다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.545-550
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• 2000

Bond between reinforcing bars and the surrounding concrete is supposed to safely transfer load in the design process of reinforced concrete structures. Bar with high relative rib area will be studied further not only static load but also dynamic loading conditions to sustain better performance of bond for reinforced concrete structures under earthquake. To determine the bond behavior of high ribbed bars in beam and column joints under repeated loads, 31 pullout specimens were tested. Bond strength increases as relative rib area increases. Also the effect of relative rib area on bond is larger in cyclic loading than in monotonic loading.

• Steel and Composite Structures
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• 제42권6호
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• pp.791-804
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• 2022

As a type of semi-rigid connection, the top and seat angle connections are popular in current structures owing to their good cyclic performance and simple erection. However, their stiffness and load bearing capacity are relatively insufficient. This study proposes two strengthening methods to further increase the stiffness and strength of bolted-angle joints while maintaining satisfactory energy dissipation capacity (EDC) and ductility. Cyclic loading tests were conducted on six joint specimens with different strengthened angle components. Based on the test results, the influence of the following important factors on the cyclic behavior of steel joint specimens was investigated: the position of the rib stiffeners (edge rib stiffeners and middle rib stiffener), steel strength grade of rib stiffeners (Q345 and Q690), and additional stiffeners or not. In addition, the finite element models of these specimens were built and validated through a comparison of experimental and numerical results. The stiffness and bearing capacity of the bolted-angle joints could be improved significantly by utilizing the novel strengthened joints proposed in this study. Moreover, this can be achieved with almost no increase in the amount of steel required, and the EDC of this joint could also satisfy the requirements of seismic codes from various countries.