• 해양환경안전학회지
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• 제21권6호
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• pp.778-783
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• 2015

본 연구는 해상에서의 안전사고의 경감과 국민의 생명을 보호하기 위한 목적으로 자체 연구를 수행하여 FRP의 수리공법인 Butt Joint, Lap Joint, V-Scarf Joint(12t, 16t, 20t), X-Scarf Joint(12t 16t, 20t)의 인장강도와 굽힘강도를 통해 이음방식에 따른 구조강도 특성을 실험하였다. 이음 방법에 따른 인장강도와 굽힘강도의 시험편을 종합 분석한 결과, 인장강도의 강도와 굽힘강도의 그래프 패턴은 비슷한 양상으로 증가와 감소를 하였으며, 인장강도와 굽힘강도 모두 X-Scarf-Butt Joint-V-Scarf-Lap Joint 순으로 강도가 우수하였다. 인장강도는 강도특성이 가장 우수한 X-Scarf라 하더라도 Basic Material의 57% 수준의 강도를 나타내었고 굽힘강도는 X-Scarf가 Basic Material의 77% 수준의 강도를 나타내었다. 종합적으로 Over-Lay 구분을 포함하여 X-Scarf 12t 이음이 인장강도, 굽힘강도 특성이 우수하였으며 Lap Joint가 가장 좋지 않았다. Scarf 이음시 Taper 길이에 따른 강도의 차이는 V-Scarf 이음은 Taper의 길이가 가장 큰 20t가 인장강도, 굽힘강도 특성이 우수한 반면 X-Scarf 이음은 Taper의 길이가 가장 짧은 12t가 인장강도, 굽힘강도 특성이 우수하여 상반되는 결과를 나타내었다. 선박에는 많은 Stress가 작용하여 시험편만을 가지고 실험한 본 연구와 직접적인 비교는 힘들지만, 재료의 가장 기본 특성을 인장강도와 굽힘강도 시험을 통해 확인할 수 있다. FRP 국부적인 수리 방법인 Butt Joint, Lap Joint, V-Scarf, X-Scarf 4가지의 이음방법에 따른 시험값과 모재 대비 감소되는 비율을 제시하였고 추가적으로 V-Scarf와 X-Scarf의 Taper 길이별 특성을 12t, 16t, 20t로 구분한 결과값을 제시함으로써 수리 현장에서의 위치별 특성에 맞는 수리 방법의 응용이 가능하도록 하였다.

• Advances in aircraft and spacecraft science
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• 제5권3호
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• pp.401-410
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• 2018

The aim of this work is to optimize the geometrical parameters as the adhesive thickness and the beveled angle to reduce the edge effect of the scarf and V bounded joint. A finite element analysis is done to define the generated stresses in the bounded joint. The geometrical optimum is obtained using the Experimental Design Method. Results show that the double scarf (V) joint is better than the simple scarf bounded joint.

• Composites Research
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• 제32권1호
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• pp.37-44
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• 2019

스카프 접착 조인트를 마이크로 볼트로 보강하였을 때, 볼트의 보강효과를 얻을 수 있는지를 시험으로 연구하였다. 스카프 형상에 따른 조인트 보강효과를 확인하기 위해 3가지 스카프비(1/10, 1/20, 1/30)를 고려하였다. 접착면적에 따른 핀의 밀도를 동일하게 유지하기 위해, 1/10, 1/20, 1/30 스카프비를 가지는 조인트에 각각 16, 32, 48개의 볼트를 보강하였다. 기준값을 획득하기 위해 접착제로만 체결된 조인트와 마이크로 볼트만 사용한 조인트에 대한 시험도 수행하였다. 시험 결과 접착제만 적용한 경우, 각 스카프비(1/10, 1/20, 1/30)에 따른 파손하중은 29.7, 39.6, 44.8 kN로 나타났다. 마이크로 볼트로 보강한 경우 파손하중은 스카프비에 따라 각각 28.4, 37.2, 40.1 kN으로 나타났는데, 순수 접착 조인트 파손하중의 96, 94, 90%에 해당한다. 마이크로 볼트만 사용한 경우, 파손하중은 접착 조인트 인장강도의 13-25%에 불과하였다. 스카프비 1/10 조인트의 피로시험 결과 접착제와 볼트를 동시에 사용한 하이브리드 조인트의 피로강도가 접착제만 사용한 경우의 피로강도보다 증가하였지만, 증가율은 2-3%로 미미하였다. 본 연구를 통해 박리응력이 파손의 주원인이 되는 구조물에서와 달리, 전단응력이 파손의 주원인이 되는 스카프 조인트의 경우 마이크로 볼트의 보강효과는 나타나지 않는 것을 확인하였다.

• 대한족부족관절학회지
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• 제20권4호
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• pp.152-157
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• 2016

Purpose: To evaluate the effect of shortening scarf osteotomy on pain relief and range of motion (ROM) of the first metatarsophalangeal joint in hallux rigidus patients. Materials and Methods: Twenty-three cases of 19 patients who had been treated with shortening scarf osteotomy for the hallux rigidus between January 2007 and December 2013 were reviewed. The mean follow-up period was 21.4 months, and the mean age was 59.2 years. The first metatarsal bone was shortened until the ROM of the first metatarsophalangeal joint was greater than $80^{\circ}$ or $40^{\circ}$ of dorsiflexion. The length shortened by scarf osteotomy was measured. The authors also measured and compared the joint interval difference of the standing foot using an anteroposterior radiography. Moreover, the difference of ROM of the first metatarsophalangeal joint between the preoperative and final follow-up periods was also compared. The clinical results were evaluated and compared using the American Orthopaedic Foot and Ankle Society (AOFAS) scoring system and visual analogue scale (VAS) score. Results: The mean shortening length was about 6.5 mm (range, 4~9 mm). The joint space has been increased to 1.8 mm, and the ROM of the first metatarsophalangeal joint has also been increased to $18.4^{\circ}$ after the operation. In three cases, the postoperative ROM has been decreased to less $10^{\circ}$. The AOFAS score has been improved from 41.7 (range, 32~55) to 86.2 (range, 65~95), and the VAS score was also decreased from 3.7 (range, 3~5) to 1.3 (range, 0~3). Two cases have shown no decrease in pain even after the operation. Conclusion: Shortening scarf osteotomy was found to decrease joint pain by decompressing the pressure of the first metatarsophalangeal joint. This osteotomy also helped improve the ROM of the first metatarsophalangeal joint. Shortening scarf osteotomy can be considered one of the effective methods for joint preservation.

• 대한족부족관절학회지
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• 제21권3호
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• pp.93-97
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• 2017

Purpose: The aim of this study was to evaluate the radiological and clinical outcomes of scarf osteotomy for hallux valgus (HV) deformity in elderly patient with osteoporosis. Materials and Methods: A total of 58 elderly patients (mean age, 72.6 years) underwent scarf osteotomy for HV deformity between 2008 and 2015. The mean follow-up period was 24.4 months. Of the 58 patients, 42 were diagnosed with osteoporosis and 16 were diagnosed as normal. The radiological and clinical outcomes were assessed preoperatively, postoperatively, and at final follow-up, including HV angle, intermetatarsal (IM) angle, American Orthopaedic Foot and Ankle Society (AOFAS) score, patient satisfaction, visual analogue scale (VAS), and complication. Results: There was no significant difference in HV angle and IM angle between the osteoporosis group and normal bone mineral densitometry group at all time points, preoperative, postoperative, and final follow-up. Moreover, there was no statistically significant difference between the two groups with respect to the AOFAS score and VAS evaluations. In the osteoporosis group, the mean HV angle improved from $36.7^{\circ}$ preoperatively to $11.3^{\circ}$ at the time of final follow-up, and the mean IM angle improved from $13.2^{\circ}$ to $5.7^{\circ}$. The mean AOFAS score improved from 52.6 preoperatively to 89.1 at the time of final follow-up. With respect to satisfaction, 83.4% of patients were very satisfied or satisfied. There were no serious complications, and all cases showed complete union at the osteotomy site. Conclusion: We believed that scarf osteotomy is a safe, effective procedure for the correction of elderly patients with osteoporosis.

• International Journal of Automotive Technology
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• 제6권3호
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• pp.293-303
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• 2005

Bonded dissimilar materials are being increasingly used in automobiles, aircraft, rolling stocks, electronic devices and engineering structures. Bonded dissimilar materials have several material advantages over homogeneous materials such as high strength, high reliability, light weight and vibration reduction. Due to their increased use it is necessary to understand how these materials behave under stress conditions. One important area is the analysis of the stress intensity factors for interface cracks emanating from circular holes in bonded dissimilar materials. In this study, the bonded scarf joint is selected for analysis using a model which has comprehensive mixed-mode components. The stress intensity factors were determined by using the boundary element method (BEM) on the interface cracks. Variations of scarf angles and crack lengths emanating from a centered circular hole and an edged semicircular hole in the Al/Epoxy bonded scarf joints of dissimilar materials are computed. From these results, the stress intensity factor calculations are verified. In addition, the relationship between scarf angle variation and the effect by crack length and holes are discussed.

• 한국가구학회지
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• 제17권2호
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• pp.25-34
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• 2006

This experiment was carried out to investigate the high-frequency gluing characteristics of poly vinyl acetate emulsion adhesive(PVAc) on MDF edge-glued boards. The edge-glued boards were glued lengthwise with butt, scarf, or finger joint. The wastes of MDF boards were reused as board materials. The obtained results are summarized as follows; the bending strength of edge-glued MDF increased slightly with the HF heating time, but the economically desirable heating time was 6 minutes. The bending and tensile strength of edge-glued MDF were high with scarf, finger and butt joint, in order. The strength of finger jointed MDF showed 80% of scarf jointed MDF. The effects of location of finger joints on the bending strength of edge-glued MDF were larger than those of the numbers of finger joints. The bending strength of edge-glued MDF with one joint on the middle position showed 40% decrease in comparison with non-jointed MDF.

• 대한족부족관절학회지
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• 제22권4호
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• pp.156-160
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• 2018

Purpose: Chronic tophaceous gout is a painful and disabling inflammatory disease. Surgical treatment for chronic tophaceous gout is very difficult with many complications. This study evaluated the efficacy of shortening scarf osteotomy on the treatment of chronic tophaceous gout in the 1st metatarso-phalangeal (MTP) joint. Materials and Methods: From January 2006 to December 2015, 14 patients (19 cases) who underwent axial shortening scarf osteotomy for chronic tophaceous gout were reviewed. All patients were male. The average age at the time of surgery was 59.6 years (42~66 years). The minimum follow-up was 24 months. Total removal of the tophi mass with the adhered medial capsule of the 1st MTP joint was attempted. Axial shortening scarf osteotomy was done on the 1st metatarsal shaft. The visual analogue scale (VAS) for pain and the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score was assessed preoperatively and postoperatively. The range of motion (ROM) of the 1st MTP joint was also compared pre- and postoperatively. Results: The average size of the extracted tophaceous mass was 32 mm. The mean amount of the length of metatarsal shortening was 4.9 mm. The mean ROM of the 1st MTP joint was improved from $30.4^{\circ}$ to $62.3^{\circ}$. The mean AOFAS forefoot score improved from 51.4 to 86.6 points. The mean VAS for pain improved from 4.6 to 0.3 points. Conclusion: The axial shortening scarf osteotomy used on chronic tophaceous gout could reconstruct the 1st MTP joint with an improved ROM and was free of pain. Axial shortening scarf osteotomy is suggested as a useful and effective method for the treatment of chronic tophaceous gout.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.479-483
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• 2018

Background: We developed a modified proximal scarf osteotomy technique for moderate to severe hallux valgus in an attempt to obtain better correction of the deformity. In addition, we compared the clinical and radiographic results of this modified technique with those of the classic scarf osteotomy reported in other studies. Methods: Between December 2004 and July 2009, 44 cases of modified proximal scarf osteotomy was performed in 35 patients with moderate hallux valgus. The American Orthopedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) score, range of motion of the first metatarsophalangeal joint, and radiographic results were evaluated. Results: The mean hallux valgus angle and the mean first intermetatarsal angle improved from an average of $32.2^{\circ}$ and $14.3^{\circ}$, respectively, to an average of $12.5^{\circ}$ and $8.6^{\circ}$, respectively. The distal metatarsal articular angle improved from an average of $18.7^{\circ}$ to $12.4^{\circ}$. The preoperative mean AOFAS and VAS scores were 47 points and 7 points, respectively, which improved to 86 points and 1 point, respectively, at the final follow-up. Limited range of motion occurred in two cases postoperatively. The height of the first metatarsal-cuneiform joint, which was an average of 15.9 mm preoperatively, did not change. The first metatarsal-talus angle increased from an average of $4.1^{\circ}$ to $7.1^{\circ}$. Conclusions: The modified proximal scarf osteotomy for the treatment of moderate hallux valgus showed similar results with the classic scarf osteotomy with regard to changes in the first intermetatarsal angle and postoperative satisfaction. Therefore, we suggest the modified proximal scarf osteotomy be considered as well as other proximal osteotomy in the treatment of moderate to severe hallux valgus.

• 대한족부족관절학회지
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• 제17권4호
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• pp.272-276
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• 2013

Purpose: Recurrence is one of the most common complications after primary correction for hallux valgus deformities. The purpose of this study was to evaluate the usefulness of Scarf osteotomy with axial decompression in the treatment of recurrent hallux valgus. Materials and Methods: From April 2006 to April 2011, 14 cases (12 patients) of recurrent hallux valgus were managed with shortening Scarf osteotomy. Preoperative and postoperative radiographs were reviewed for the measurement of the hallux valgus angle (HVA), intermetatarsal angle (IMA), and the amount of the $1^{st}$ metatarsal shortening. Clinical outcomes including the visual analogue scale (VAS), the AOFAS score, and the range of motion [ROM] of the 1st metatarsophalangeal (MTP) joint were evaluated. Results: The mean HVA decreased from 27.9 degrees to 5.2 and the mean IMA decreased from 12.9 to 3.4. The mean VAS improved from 5.3 to 0.3 and the mean AOFAS score improved from 41 to 90. The mean amount of the 1st metatarsal shortening was 3.4 mm (2-5). The mean ROM of the $1^{st}$ MTP joint improved from 22 degrees (15-35) to 68 (55-75). Conclusion: Scarf osteotomy associated with axial decompression can be a useful revision procedure for the treatment of recurrent hallux valgus deformity.