• 한국자동차공학회논문집
• /
• 제6권1호
• /
• pp.143-150
• /
• 1998

The evaluation of joint fatigue strength of light weight materials for electrical vehicle body has been performed through single lap joint tests with the design parameters such as joint style, adherend, bonding overlap length and bonding thickness. Fatigue strength was evaluated through 5-Hz, tension-tension, load controlled test with the stress ratio zero value. It is experimentally observed that fatigue strength of joint increases for the increase of overlap length. The combinations of Al-Al and Al-FRP adherends show that fatigue strength of joint is hardly changed for the increase of bonding thickness, but FRP-FRP adherend specimen shows that fatigue strength of joint increases after decreases for the increase of bonding thickness. Al-Al adherend specimen has much higher fatigue length than Al-FRP and FRP-FRP adherend specimens. Riveting at adgesive bonded joint gives little effect on fatigue strength.

• 대한방사선기술학회지:방사선기술과학
• /
• 제43권3호
• /
• pp.161-167
• /
• 2020

This study aimed to found out the effect of patellofemoral overlap distance by changing femur thickness and center X-ray angles in Merchant method images. Based on the femur thickness, it suggested tube angle minimizes overlap. It was conducted by Merchant method, a knee tangential view, and the image was obtained by changing the thigh thickness from 14 to 20 cm and the center ray angle from 60°, 57°, 55°. The images were measured by five researchers using a method of measuring the overlap, which was designed by them. The results showed at 60°, 57°, 55° angle, the patellofemoral overlap distance resulted in 0.47±0.66 to 20.89±0.65 cm, 2.26±0.28 to 15.73±0.62 cm, 1.39 ± 0.83 to 12.49 ± 0.37 cm. However, for 57° and 55°, no overlap in thickness under 14.5 and 14 to 15.5 didn't appear. it showed high correlation between femur thickness and overlap. The difference in the mean value of overlap in each group showed a statistically significant difference (p<0.01), all were classified as independent groups in the post-hoc test. In all images, the patellofemoral overlap distance increased as the thickness increased, and at the average thickness of Korean men and women, overlap decreased when reducing center ray. When conducting Merchant tests on Koreans, it was suggested it would be useful to use 57° angle because it minimize the effects of overlap and intrusions of tibia.

• 한국자동차공학회논문집
• /
• 제5권2호
• /
• pp.87-93
• /
• 1997

The bonding strength evaluation of light weight materials for electrical vehicle applications has been performed through single lap joint tests in which the design parameters such as fillet, joint style, adherend, bonding overlap length,bonding thickness, and environmental condition(soaking time in $25^{\circ}C$ water) are considered. It is experimentally oberved that lap shear strength of joint increases for higher fillet height, longer overlap length, and thinner bonding layer thickness. Al-Al adherend combination shows much higher lap shear strength than AL-FRP and FRP-FRP adherend combinations. Riveting at adhesive bonded joint of AL-AL adherend combination makes lap shear strength decrease. Effect of soaking time on lap shear strength is negligible.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2004년도 학술대회지
• /
• pp.39-44
• /
• 2004

A heat and room temperature construction method of asphalt have been mainly applying to rooftop waterproofing in concrete structure, and the rest construction method are sheet, membrane and mortar waterproofing construction method. In particular, joint method in sheet waterproof method is as overlap joint which on being reinforced with fiber and tape, have been applying for job site to mechanical fix using protection disk and anchorage and metal ironwork on the end of sheet. These construction method cause cutting off joint of sheet as behavior of structure according to repairs of sheet itself and thermal conduct, outdoor air environment. In conclusion, we analyzed and examined the application of various sheets and piece ashes about superior 'I' joint which divide from one and the other sheet and progressed about joint construction method of fixing method for overlap.

• 한국산업융합학회 논문집
• /
• 제24권6_2호
• /
• pp.883-890
• /
• 2021

In this study, joint analysis was conducted on the rock slope by aerial surveying using UAV. Aerial photos were taken using UAV to measure the directionality of the rock slope exposed to the site, and the directionality of the joint was analyzed using the photographed photos. UAV photography was taken under conditions of 90% overlap and an altitude of 50m. The photographing path was measured in the horizontal, vertical, and oblique directions based on the slope, and the joint characteristics were analyzed. Aerial surveying research on the joint directionality analysis of rock slopes is still incomplete, and the method for accurate joint directionality analysis is not presented strategically, so it is difficult to apply it in design. Through the results of this study, we would like to propose an flight photographing technique for the investigation of rock joints. As a result of the study, in the case of the joint investigation of the rock slope using UAV, it was necessary to change conditions such as altitude, aerial photography route, and overlap according to the size of the joint according to the site conditions.

• 항공우주시스템공학회지
• /
• 제17권2호
• /
• pp.62-70
• /
• 2023

본 논문에서는 두 가지 복합재료의 플라이를 부분적 또는 전체적으로 적층하여 접합시킨 플라이 오버랩 조인트 구조의 기하학적 특징을 이용하여 응력-수명(S-N) 선도 및 피로 수명을 예측하는 기법을 제안한다. 구조의 피로 특성에 영향을 주는 기하학적 특징을 변수로 선정하였다. 기하학적 변수와 복합재 피로 모델인 Epaarachchi-Clausen 모델을 구성하는 재료상수의 관계를 분석하여 두 요소의 관계식을 제안하였다. 제안한 방법의 예측 정확도 검증을 위해서 CFRP/GFRP 플라이 오버랩 조인트의 피로 수명을 예측하였다. 예측된 수명과 시험 데이터 기반 모델로 얻은 수명을 실제 수명에 비교하였다. 또한, 예측된 S-N 선도의 결정 계수를 계산함으로써 높은 예측 정확도를 확인하였다.

• Journal of Welding and Joining
• /
• 제19권3호
• /
• pp.342-347
• /
• 2001

Recently, adhesive-bonding technique is wifely used in manufacturing structures. Stress and strain analysis of joints are essential to design adhesive-bonded joints structure. The single-lap adhesive joint is the design dominating the range of adhesive joints. In this study, single-lap specimens with different joint dimensions were used for the tensile-shear test and finite element calculation in of order to investigate the effect of overlap length and adhesive-bonding thickness on adhesive strength and stress distribution of the joints. Consequently, it was found that overlap lap size and thickness can be important parameters of structure joints using adhesive bonding, which is effected on adhesive strength.

• 접착 및 계면
• /
• 제7권4호
• /
• pp.1-9
• /
• 2006

The single lap joint is the most studied joint in the literature in terms of both theory and practice. It is easy to manufacture and the lap shear strength is a useful value for strength assessment and quality control. Simple design rules exist such as the one present in standard ASTM 1002 or in a recent paper by Adams and Davies. The main factors that have an influence on the lap shear strength are the type of adhesive, i.e. ductile or brittle, the adherend yield strength and the overlap length. The overlap increases the shear strength almost linearly if the adhesive is sufficiently ductile and the adherend does not yield. For substrates that yield, a plateau is reached for a certain value of overlap corresponding to the yielding of the adherend. For intermediate or brittle adhesives, the analysis is more complex and needs further investigation. In order to quantify the influence of the adhesive, the adherend and the overlap on the lap shear strength, the experimental design technique of Taguchi was used. An experimental matrix of 27 tests was designed and each test was repeated three times. The influence of each variable could be assessed as well as the interactions between them using the statistical software Statview. The results show that the most important variable on the lap shear strength is the overlap length followed by the type of adherend.

• 대한기계학회논문집A
• /
• 제33권6호
• /
• pp.560-567
• /
• 2009

This paper was designed to estimate the adhesion strength of galvannealed coatings on steel sheets. The adhesion strength were evaluated using single lap - shear tests where the lap joint was bonded by structural adhesive. Tests were performed for overlap length of 5mm, 10mm and 15 mm and three directions (0, 45, 90) of steel sheets used as the adherend of the overlap joint. After the tests, FE simulations of the single lap-shear test were also carried out to observe the stress distribution in the interface between the adhesive and the coated sheet. The results showed that the joint failure loads obtained from the tensile tests of bonded single lap-joints were the same, regardless of overlap lengths and directions of steel sheets. Also, the failure of galvannealed coatings greatly depended on shear stress distribution in the interface and the value was about 30MPa.

• 문화기술의 융합
• /
• 제6권4호
• /
• pp.685-692
• /
• 2020

본 연구에서는 철근 겹침이음 위치가 부적정하게 시공된 사례를 바탕으로 콘크리트 구조기준에서 제시한 설치기준에 대하여 분석 및 고찰을 하였으며, 현행 구조기준에서 제시한 겹침이음에 대한 기준이 적정함을 해석적으로 입증하였다. 실제 종방향 균열이 발생된 지하 박스구조물 단면에 대한 철근 겹침이음부의 철근강도감소비 및 설계유효 모멘트를 산출하여 철근 겹침이음부의 균열 발생원인에 대하여 해석적으로 입증하였다. 연구결과, 최대 인장응력이 발생되는 지하 박스구조물 중앙부에 철근 겹침이음이 설치될 경우 철근 겹침이음부의 철근강도감소비는 82.8% 수준인 것으로 분석되었다. 따라서, 콘크리트 구조기준에서 정하고 있는 바와 같이 철근 겹침이음부의 위치는 최대 인장응력이 발생하는 지점을 피해야 하며, 부득이하게 겹침이음이 부적정한 위치에 설치되는 경우 본 연구에서 검토한 바와 같이 충분한 겹침이음길이를 확보하여야 하며, 구조물 단면력에 대하여 검토하여 충분한 안전율을 확보하는 것이 중장기적인 균열 제어 방법으로 적정할 것으로 검토되었다.