• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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• pp.169-174
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• 2002

We can consider that the study on early evaluation of compressive strength and durability of concrete is useful to raise safety of quality control of concrete. In this paper, was proposed to method early to predict strength and durability of concrete with parameter, such as Water/cement(W/C) ratio and steam curing conditions. Through analyzing the relationship between the compressive strength and the amount of chloride penetration into concrete specimens, a new formula early estimating durability of the concrete structure was suggested.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.540-543
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• 2004

In this study, the validity of the grid softened strut-tie model method suggested for concrete member analysis is examined through the ultimate strength evaluation of the reinforced concrete beams. The evaluated results of ultimate strength by the grid softened strut-tie model method were compared with those by the ACI 318-02 and the modified compression field theory, and European codes.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1713-1718
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• 2010

An ultimate strength evaluation of the through plate girder bridge using nonlinear inelastic analysis is presented. In this method, separate member capacity checks after analysis are not required, because the stability and strength of the structural system and its component members can be rigorously treated in analysis. The method captures the inelastic redistribution of internal forces throughout a structural system, and allows an economic use of material for highly indeterminate steel bridges.

• 대한기계학회논문집A
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• 제20권7호
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• pp.2087-2096
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• 1996

Recentrly advantages in composite and light weight material techniques have led to the increased use of bonded dissimilar materials such as ceramics/metal bonded joints, IC package, brazing, coating and soldering in the various industries. It is required to analyze the evaluation method of fracture strength and design methodology of bonded joints in dissimilar materials. Stress singularity according to changes of scarf angles for bonded scarf joints in dissimilar materials was investigated by the boundary element method and static experiments. In this paper, effect of the stress singularity factors at the interface edges of scarf joints on various dissmilar materials combinations were investigated by analysis of its stress and stress singularity index using 2-dimensional elastic program of boundary element method. And the variations of stress singularity index by changes for Young's modulus ratios of materials and scarf angles were investigated. Also, it is found that stress singularities at bonded interface edges are disappeared for certain combination of scarf angle in a pair of bonded dissimilar materials. As the results, it is proposed that the strength evaluation by using stress singularity factors, $\Gamma$, considering stress singularity at the interface edges of bonded dissimilar materials, is very useful.

• 대한조선학회논문집
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• 제56권3호
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• pp.187-199
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• 2019

In the case of gas carriers and oil tankers, pipes are installed on the upper deck as a moving passage to load LPG, LNG, crude oil, etc. Pipes used for loading or unloading liquid cargo in cargo holds are connected to the hull through support structures. However, many cases of hull damage have been reported where the various equipment and support structures are installed on the upper deck. It is assumed that not only the structural discontinuity where the hull and the pipe support structure meet, but also action due to the pipe loads and the hull girder bending moment are simultaneously affected. This paper deals with the design and strength evaluation of the support structure of pipes and cables installed on the upper deck of commercial ships and offshore structures. For these supporting structures, design conditions and working loads were defined. The design procedure was established through the structure analysis on the method of determining the member dimensions. A series of finite element analysis was performed on the factors to be considered in the design and the effects were discussed. The accuracy and design periods of the strength evaluation was improved and reduced by application of the automation program in the finite element analysis. It is also expected that the design reliability of the shipyard is improved.

• 한국건설순환자원학회논문집
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• 제3권4호
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• pp.320-327
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• 2015

본 연구에서는 무근 콘크리트 터널 라이닝의 품질 평가를 위해 초음파법을 사용하여 현장실험을 실시하였으며, 라이닝 콘크리트의 품질을 평가하였다. 초음파 탐사기의 센서 중심간격과 센서의 순간격을 기준으로 각각의 전달속도를 평가한 후 평균값에 대한 수렴정도를 예측하여 평균값을 초음파 전달속도로 구하면 직접법에서 얻어지는 결과만큼 신뢰성 있게 얻어질 수 있음을 보였다. 초음파속도에 의해 콘크리트 강도를 정량적으로 평가하는 방안은 신뢰성이 부족하며 초음파 전달속도에 따라 등급별로 콘크리트를 평가하는 방안이 보다 합리적인 평가 방안임을 나타내었다.

• 교육시설 논문지
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• 제21권2호
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• pp.33-39
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• 2014

In the case of low-rise buildings in seismic performance evaluation, lateral force resistance of the pillars affects the seismic performance of the building. Evaluation of the seismic performance of the column is determined by the holding performance is evaluated by comparing the shear strength and bending strength it was destroyed bylow intensity. In case of the school building, in order to install the large windows for ventilation and lighting of the partition walls are located between the pillars. The case of the pillars of these, shear failure occurs in the event of an earthquake is often, in the seismic performance evaluation, partition wall and the wall of the shim is evaluated ignoring, pillar of the general pillars If you have to calculate the results of the seismic performance distorted that are destroyed by bending behavior can be evaluated as often. Results of the study, when assessed by distinguishing the effective length of the column, it was found that when a seismic load is applied, it is possible to accurately predict the failure mode, reliable results of seismic performance evaluation of the school building.

• 한국도로학회논문집
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• 제16권5호
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• pp.1-8
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• 2014

PURPOSES : The objective of this study is to evaluate the bond strength of asphalt emulsions including polymer-modified emulsions for chip seals and fog seals using the bitumen bond strength (BBS) test. METHODS : For the laboratory testing, the Pneumatic Adhesion tensile Testing Instrument(PATTI) device is used to measure the bond strength between the asphalt emulsion and aggregate substrate based on the AASHTO TP-91. In order to conduct all the tests in controled condition, all test procedures are performed in the environmental chamber. The CRS-2L and the SBS CRS-2P emulsions are used as a polymer-modified emulsion, and then unmodified emulsion, the CRS-2, is compared for the evaluation of chip seal performance. For the fog seal performance evaluation, two types of polymer-modified emulsions and one of unmodified emulsion, the CSS-1H, are employed. For chip seal study, the BBS tests are performed at 30, 60, 120, and 240 minutes of curing times with curing and testing temperatures of $15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$. The fog seal tests are conducted at 30, 60, 90, 120, 180 minutes, and 24 hours with curing and testing temperatures of $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$. RESULTS AND CONCLUSIONS : Overall, chip seal emulsions and fog seal emulsions show the similar bond strength trend. At the same testing condition, polymer-modified emulsions show better bond strength than unmodified emulsions. Also, there is no significant difference between polymer-modified emulsions. One of important findings is that the most bond strength reaches their final bond strength within one hour of curing time. Therefore, the early curing time plays a vital role in the performance of chip seals and fog seals.

• 한국철도학회논문집
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• 제5권2호
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• pp.118-124
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• 2002

The failure probability of wheel beyond 10$\^$7/ cycles is achieved by the strengths-stress interference model for the evaluation of fatigue strength and reliability in the wheel, From plane bending fatigue test results, the fatigue life (N$\_$f/) for the smooth and 200㎛ holed specimens can be represented as $\sigma$$\_$a/ = 1326N$\_$f/$\^$-0.10/ and $\sigma$$\_$a/ = 2894N$\_$f/$\^$-0.18/. Respectively, fatigue strength of the wheel at beyond 10$\^$7/cycles was about 332 MPa. And, the fatigue strength for the specimen with a micro hole (d=200㎛) which simulated an inclusion on the wheel surface was about 235 MPa. Thus, a micro hole (d=200㎛) caused about 30% reduction of fatigue strength of the specimen. The failure probabilities for the smooth and micro-holed specimens, derived from the strength-stress interference model, are 0.0148% and 13.05%, respectively. The current finding suggests that at least 200 ㎛ sized inclusion, which might be produced during manufacturing process, will cause a critical effect on integrity of the railway vehicle.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.213-218
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• 2006

For an evaluation of fatigue strength, the dynamic stress test of bogie frame for new electrical multiple unit was practiced in the real route line. And this results are summaries for a decision whether this vehicle can be operated safely for more than 25 years according to the international standard of the evaluation and its procedure.