• Journal of Trauma and Injury
• /
• 제26권3호
• /
• pp.218-221
• /
• 2013

A patella sleeve fracture is a type of avulsion fracture in which a small osseous fragment gets, along with a sleeve of periosteum and cartilage, is pulled off from the patella. The avulsed sleeve of cartilage and periosteum is not apparent on plain radiographs, which can result in a missed diagnosis or an underestimate of the extent of injury. An avulsion or sleeve fracture of the patella in a child can occur at the superior or the inferior pole of the patella. However, most reported cases of sleeve fractures involve the inferior patellar pole, with fractures involving the superior patellar pole being very rare. The authors report a case of a sleeve fracture of the superior pole of the patella in an adolescent; the fracture was diagnosed with magnetic resonance imaging (MRI) and was treated with surgery after early diagnosis. The course was uneventful, and the outcome was excellent.

• 대한정형외과스포츠의학회지
• /
• 제8권2호
• /
• pp.121-124
• /
• 2009

소아에서의 슬개골 골절은 성인을 포함한 전체 슬개골 골절의 약 2% 미만에서 발생하고, 모든 소아 골절의 약 1% 정도로 매우 드물게 발생한다. 성장중인 슬개골은 성인에서의 슬개골 골절과는 달리 골연골 골절 또는 견열 골절의 형태로 흔히 발생하며, 그 형태는 주로 소매형 골절로 나타난다. 소아 슬개골의 견열 골절 또는 소매형 골절은 슬개골의 상단부 혹은 하단부에서 발생하나, 대부분 슬개골 하단부가 주를 이루며, 상단부에 생긴 경우는 드물다. 저자들은 16세 소아에서 슬개골 상단부의 소매형 골절 1례를 경험하여 이를 문헌고찰과 함께 보고하는 바이다.

• 한국농공학회논문집
• /
• 제46권1호
• /
• pp.41-51
• /
• 2004

FRP re-bar in concrete structures could be used as a substitute of steel re-bars for that cases in which aggressive environment produce high steel corrosion, or lightweight is an important design factor, or transportation cost increase significantly with the weight of the materials. But FRP fibers have only linearly elastic stress-strain behavior; whereas, steel re-bar has linear elastic behavior up to the yield point followed by large plastic deformation and strain hardening. Thus, the current FRP re-bars are not suitable concrete reinforcement where a large amount of plastic deformation prior to collapse is required. The main objectives of this study in to evaluate the tensile behavior and the fracture mode of hybrid FRP re-bar. Fracture mode of hybrid FRP re-bar is unique. The only feature common to the failure of the hybrid FRP re-bars and the composite is the random fiber fracture and multilevel fracture of sleeve fibers, and the resin laceration behavior in both the sleeve and the core areas. Also, the result of the tensile and interlaminar shear stress test results of hybrid FRP re-bar can provide its excellent tensile strength-strain and interlaminar stress-strain behavior.

• 한국구조물진단유지관리공학회 논문집
• /
• 제16권1호
• /
• pp.27-34
• /
• 2012

본 연구에서는 기존의 모르타르 충전식 슬리브 철근이음에 대한 부착강도식으로부터 유도한 이 철근이음의 파괴모드 추정방법을 이용하여, AIJ 규준에 의하여 평가한 이 슬리브 철근이음의 강성을 검토하였다. 이것을 위하여 261개 모르타르 충전식 슬리브 철근이음의 기존 실험자료를 채택하여 실험의 결과를 분석한 결과에 의하면 모르타르 충전식 철근이음의 파괴모드 추정방법은 돌기가 없는 강관 슬리브에 SD500 철근을 사용한 철근이음을 제외한 모르타르 충전식 슬리브 철근이음에 대한 강성을 효과적으로 평가할 수 있었다. 그리고 이 슬리브 철근이음의 파괴모드 추정방법에 적용하여 철근의 인장파단 영역에 있는 실험체 중에 주물 슬리브와 돌기가 있는 강관 슬리브를 사용한 실험체에서 SD400 철근을 사용한 경우는 98%, SD500 철근을 사용한 경우는 모든 실험체가 단조가력 시의 강성이 AIJ 규준의 A급 이상인 것으로 나타났고, 철근의 인장파단 영역에 있는 모든 실험체는 슬리브의 종류와 슬리브에 매입한 철근 종류에 관계없이 반복가력 시의 강성이 AIJ 규준의 A급 이상인 것으로 나타났다.

• 한국전기전자재료학회논문지
• /
• 제21권11호
• /
• pp.1036-1041
• /
• 2008

According to previous report, aged sleeves of old transmission line showed several defaulted installation patterns, which was biased or corrosive-fractured of steel sleeve installed cases. These defects can cause serious accidents such as rapid increasing of sag or falling out of overhead conductor from sleeves. Consequently, the defects lead to the major power outage. Corrosion of steel sleeve is a typical defect by aging of sleeves. And it occupied almost 25 percent of investigated aged sleeves. This paper studied thermal properties and tension for ACSR conductor in case of fractured steel sleeve model by corrosion. The temperature distribution within overhead conductor has a specific gradient. Thermal properties of splice connectors(sleeve and clamp) showed normal behavior. However, mechanical properties were worse than normal sleeves. The detailed results were presented in the text.

• Journal of Welding and Joining
• /
• 제17권1호
• /
• pp.82-87
• /
• 1999

The basic remote sleeve repair-welding technology by the pulsed Nd:YAG laser for increasing the lifetime of the steam generator tube in a nuclear power plant has been developed. The relationship between the connection width and welding parameters have been investigated for the fundamental research to apply the sleeve-repair-welding technique to the nuclear industry. The Inconel 600 tube and Inconel 690 sleeve used for high temperature and high pressure service were welded as round lap welding by Nd:YAG laser. It was observed that the tensile shear strength, 340MPa of the welded specimen is equivalent to about 60% of that of the base metal (Inconel 600), 550MPa. The difference between the hardness of the base metal and that of the laser welds was about 10%. Ductile fracture was partly occurred in the weld but the cracking has not been observed. In spite of absence of the crack, the strength of welds was not sufficient in terms of the tensile shear strength.

• 대한족부족관절학회지
• /
• 제27권2호
• /
• pp.39-42
• /
• 2023

A ruptured Achilles tendon at the calcaneus attachment, which does not include a bone that can be fixed, is called 'sleeve avulsion'. A small amount of tendon in the calcaneal region can be sutured to the proximal portion of the ruptured Achilles tendon or insufficient bone to be fixed. Hence, tendon-bone healing is expected, but the results are not good compared to other parts of the tear. The incidence of Achilles tendon rupture is 7 to 40 per 100,000 patients, and 25% of patients undergo direct suture or reconstruction surgery, and 7.6% of patients with sleeve avulsion injuries undergo surgery. Surgical treatment may be a better choice for Achilles tendon sleeve avulsion because no successful case of conservative treatment has been reported. Distal wounds above the ruptured tendon adjacent to the bony eminence can have wound healing problems because of the thin, soft tissue and hypovascularity. An appropriate surgical method must be selected for each patient.

• Steel and Composite Structures
• /
• 제52권2호
• /
• pp.165-182
• /
• 2024

Grouted sleeve splice (GSS) is an effective type of connection applied in the precast concrete structures as it has the advantages of rapidly assembly and reliable strength. To decrease the weight and cost of vertical rebar connection in precast shear walls, a light-weight sleeve is designed according to the thick-cylinder theory. Mechanical behaviour of the light-weighted GSS is investigated through experimental analysis. Two failure modes, such as rebar fracture failure and rebar pull-out failure, are found. The load-displacement curves exhibit four different stages: elastic stage, yield stage, strengthening stage, and necking stage. The bond strength between the rebar and the grout increases gradually from outer position to inner position of the sleeve, and it reaches the maximum value at the centre of the anchorage length. A finite element model predicting the mechanical properties of the light-weighted GSS is developed based on the Concrete Damage Plasticity (CDP) model and the Brittle Cracking (BC) model. The effect of the rebar anchorage length is significant, while the increase of the thickness of sleeve and the grout strength are not very effective. A model for estimating ultimate load, including factors of inner diameter of sleeves, anchorage length, and rebar diameter, is proposed. The proposed model shows good agreement with various test data.

• Clinics in Shoulder and Elbow
• /
• 제9권2호
• /
• pp.207-210
• /
• 2006

We presented a case of posteriorly displaced fracture of the distal clavicle in Child. The closed reduction was failed due to posteriorly displaced proximal fragment and interpositon of trapezius muscle and periosteum. We found that periosteal sleeve and coracoclaviclar ligament and acromioclavicular ligament was intact. The open reduction should be considered for the treatment of the irreducible posteriorly displaced fracture of the distal clavicle in child.

• 대한기계학회논문집A
• /
• 제41권11호
• /
• pp.1021-1033
• /
• 2017

본 연구에서는 매설가스배관의 강 슬리브 보수 용접부에 대한 피로수명에 미치는 보수 용접 공정 변수별 영향을 고찰하여 최적 공정을 수립하였다. 상용 유한요소 해석프로그램인 ABAQUS를 이용한 연계 연성 온도-응력 해석을 통해 강 슬리브 보수용접 시 보수용접부에 발생하는 용접 잔류응력을 도출하였다. 또한, 유한요소 선형탄성 응력해석을 통해 운전응력 변이도 도출하였다. 도출된 용접 잔류응력과 운전응력 변이를 입력값으로써 구조응력/파괴역학 접근법에 대입하여 강 슬리브 보수용접부의 피로수명을 평가하였다. 다양한 보수용접 공정 변수에 대한 유한요소해석과 피로평가를 수행하여 공정변수별 피로수명에 미치는 영향을 고찰하였다. 최종적으로는 고찰한 피로수명에 미치는 공정변수별 영항 결과를 토대로 공정 및 경제적 비용을 최소화하고 피로수명을 적절히 향상시킬 수 있는 최적 방안을 도출하였다.