As a safety device, a rupture disc are used to control pressure to minimize the explosion risk once the internal pressure of high pressure equipment exceeds a critical level. In this paper, optimization method was developed to secure optimal design of domed Rupture disks. The parameter analysis was performed through design of experiment to parameter of Rupture disk made of AISI 316.The Diameter, Thickness and Hight of Rupture disk were selected as design parameters for design parameter analysis. The results of parameter analysis revealed that the Diameter, thickness and hight were burst pressure-sensitive design parameters. Based on the valid performance factors, a regression equation to predict its performance was deducted and using the equation, an optimal design. And a sample model was fabricated, followed by burst pressure testing, after optimal design and analytical verification. In this research, it is verified that the optimal design method and the credibility of the analysis of this study is deemed very high. Furthermore, utilizing this mechanism would inspect the effect of the design parameter performance and increase the credibility and efficiency of a design.

췌장 가성동맥류는 췌장염이나 췌장 수술과 연관되어 종종 생명을 위협하는 합병증으로 알려져 있다. 췌장 가성동맥류가 파열되면 치명적인 출혈을 유발할 수 있으며 높은 사망률과 관련이 있기 때문에 임상적 의심과 조기 진단이 환자의 임상 경과를 호전되게 할 수 있는 중요한 역할을 한다. 가성동맥류의 치료법 중 하나로 알려진 색전술은 효과적일 수 있으나, 췌장염과 관련된 가성동맥류 파열 환자의 색전술 치료 결과에 대한 국내 연구는 적다. 이에 췌장염으로 인한 가성동맥류 파열을 진단받고 색전술로 성공적으로 치료받은 환자들에 대한 증례를 보고한다.

In this paper, based on the existing research, we define the parameters for the number of ignition devices to be applied to the pyrovalve, the operation and airtightness according to the temperature, the material of the nipple and the thickness of the fractured part, and ANSYS Ver. 19.2 was used to analyze the FEA model, and a comparative analysis was conducted through structure analysis according to the piston shape of the pyrovalve. In addition, an experimental study was conducted by manufacturing a prototype according to the design variables. As a result, high-strength pyrovalves can stably supply working fluids such as fuel and oxidizer for space launch vehicle propulsion engines, as well as precisely control flow path switching was confirmed.

취성특성을 가진 탄소섬유복합체의 인장특성을 결정하기 위해 ASTM D 3 0 39에 따라 인장시험을 실시하였다. 극한시 점에 박리, 부분파단으로 인해 스트레인 게이지의 계측값의 변동성이 커져 신뢰성을 확보하기 어렵기 때문에 극한응력과 탄성 계수를 이용한 유효극한변형률을 제안하고, 극한계측변형률과 상호보완하였다. 특히 게이지가 비정상적으로 작용할 경우에도 적용이 가능하다는 장점이 있다. 또한 유효극한변형률을 결정하는 탄성계수는 단일시편에서 여러 변형률 구간에 대하여 평가하여 비교 검증할 수 있다.

P91 steel has been a highly researched material because of its applicability for high-temperature applications. Considerable efforts have been made to produce experimental creep data and develop models for creep life prediction. As creep tests are expensive and difficult to conduct, it is vital to develop authenticated empirical methods from experimental results that can be utilized for better understanding of creep behavior and can be incorporated into computational models for reliable prediction of creep life. In this research, a series of creep rupture tests are performed on the P91 specimens within a stress range of 155 MPa to 200 MPa and temperature range of 640 oC (913 K) to 675 oC (948 K). The microstructure, hardness, and fracture surfaces of the specimens are investigated. To analyze the results of the creep rupture tests at a macro level, a parameter called creep work density is derived. Then, the relationships between various creep parameters such as strain, strain rate, time to rupture, creep damage tolerance factor, and creep work density are investigated, and various empirical equations are obtained.

In turbopump type liquid rocket engines, ignition and starting are known to be the most unstable and risky section among all operating sections of the projectile. The operation of the liquid rocket engine is the process of ignition and combustion of the main combustor after the turbo pump is driven into a stable section due to the turbine driving of the turbo pump and the ignition and combustion of the gas generator by the pyro starter. In this process, the driving of related components directly influences each other, so each component must be operated with sufficient reliability. In particular, if the igniter does not supply sufficient ignition energy at a predetermined time, an explosion may occur due to stagnation of the fuel/oxidant mixture, so reliability is more important. In this study, the fracture analysis of the gas generator igniter rupture disk according to the shape was performed using computational analysis. As a result, comparative analysis was performed to obtain the optimal dimensions according to each variable condition.

The slip-weakening model developed by Ohnaka and Yamashita is extended over the breakdown zone by equating the scaling relationships for the breakdown zone and the whole rupture area. For the extension, the study uses the relationship between rupture velocity and radiation efficiency, which was derived in the theory of linear elastic fracture mechanics, and the definition of fmax given in the specific barrier model proposed by Papageorgiou and Aki. The results clearly show that the extended scaling relationship is governed by the ratio of rupture velocity to S wave velocity, and the velocity ratio can be determined by the ratio of characteristic frequencies of a Fourier amplitude spectrum, which are corner frequency, fc, and source-controlled cut-off frequency, fmax, or vice versa. The derived relationship is tested by using the characteristic frequencies extracted from previous studies of more than 130 shallow crustal events (focal depth less than 25 km, MW 3.0~7.5) that occurred in Japan. Under the assumption of a dynamic similarity, the rupture velocity estimated from fmax/fc and the modified integral timescale give quite similar scale-dependence of the rupture area to that given by Kanamori and Anderson. Also, the results for large earthquakes show good agreement to the values from a kinematic inversion in previous studies. The test results also indicate the unavailability of the spectral self-similarity proposed by Aki because of the scale-dependent rupture velocity and the rupture velocity-dependent fmax/fc; however, the results do support the local similarity asserted by Ohnaka. It is also remarkable that the relationship between the rupture velocity and fmax/fc is quite similar to Kolmogorov’s hypothesis on a similarity in the theory of isotropic turbulence.

본 연구에서는 복부대동맥류가 발생한 환자들에서의 연령과 복부대동맥류 형상에 따른 벽 응력과 파열 위험성을 평가하였다. 복부 대동맥류의 형상은 의료영상 데이터로부터 추출되어 모사되었으며, 재료 물성치 단계에서는 동맥 조직의 이방성 초탄성 성질을 모사 하기 위해 Gasser-Ogden-Holzapfel 모델을 적용하였다. 또한, 모델에서 필요한 각 재료 정수들은 환자들의 연령과 정상 조직 및 동맥 류 조직의 특성들을 고려하기 위하여 각기 다른 값들로 산정되었다. 게다가 복부대동맥류에서의 대동맥 직경과 목의 각도에 관한 상 관관계를 분석하고, 이에 대한 시리즈 시뮬레이션 역시 수행되었다. 그 결과, 복부대동맥류 환자의 연령과 대동맥 직경, 그리고 대동 맥 목의 각도에 따른 복부대동맥류의 파열 위험성이 평가되었다.

Purpose of this study is to describe the treatment, surgery, rehabilitation and return to daily life subject pectoralis major muscle rupture. The in patient with was a 26 years old, injured in training due to hyperextension and external rotation. Physical examination, manual test, and MRI were used to diagnose pectoral muscle rupture and operation took for the pectoralis major muscle rupture with allograft. The subject was referred for rehabilitation from 3 weeks. Range of motion (ROM) exercise was mainly performed until 3 months, strength was performed with tubing band, body weight, machine training and proprioceptive exercise. Shoulder range of motion (external rotation, flexion) were measured with goniometer and muscle strength (flexion, adduction, internal rotation) were measured with dynamometer. At 6momths, external rotation ROM was 50° (unaffected side 60°), and flexion almost recovered at 3 months. Muscle strength was gradually increased to 6.2kg, 15.7kg, and 27.0kg in flexion, while internal rotation The pain remained slightly after 9 months. The present results suggest that ROM exercise and strengthening exercise increase the muscle power and ROM, and decrease the pain.

A 2-year-old female Maltese dog was presented with a history of anemia and vaginal hemorrhagic discharge. Physical examination revealed severe vaginal hemorrhagic discharge, abdominal pain, pale mucous membranes, low blood pressure and dehydration. Results of serum biochemistry, hematology, venous blood gas, and electrolyte canine C-reactive protein (CRP) test revealed severe normocytic normochromic anemia, severe neutropenia, a high level of CRP, hypoglycemia, and imbalanced electrolytes. Abdominal ultrasound examination showed focal hypoechoic defect with loss of layering in uterine horn wall. A laparotomy revealed a clear reddish fluid in the abdomen, the fistula of left and right uterine horn, the purulent discharge from fistula, and symptoms of septic peritonitis near by the fistula site. The bitch underwent ovariohysterectomy and recovered without complication. Histopathological diagnosis of the uterine fistula site was adenocarcinoma.

The WUF-W moment connection is a pre-qualified connection that can be used for special moment frames specified in current seismic design specifications. Since the stress distribution near the connection varies according to access hole configuration, the cyclic performance of WUF-W connections is strongly affected by the access hole configurations. To evaluate the connection performance according to various access hole configurations, it is expensive to conduct experiments with many connection specimens. Instead, finite element analyses (FEA) can be performed. Throughout the FEA, stress and strain distribution in the connection can be monitored at each loading step. The purpose of this study is to construct nonlinear 3-dimensional FE models for accurately predicting the cyclic behavior of WUF-W connections. For predicting connection fracture using FEA, an appropriate response index detecting the incidence of connection rupture is proposed.

췌장의 점액성 낭성 종양(mucinous cystic neoplasm)은 국내 다기관 연구에 의하면 전체 췌장 낭성 종양의 약 25%를 차지하고 있다. 대부분 중년 여성에게 호발하고, 병변은 췌장 체부 및 미부에 위치하며, 점액성 낭선암(mucinous cystadenocarcinoma) 으로 악화될 수 있는데, 크기가 서서히 증가하므로 이의 파열은 매우 드문 합병증이다. 저자들은 72세 남성에서 발생한 췌장 점액성 낭선암의 자발 파열 증례를 문헌 고찰과 함께 보고하는 바이다.

A 6-year old, Greyhound bitch was presented with vaginal hemorrhage and dystocia. Physical examination revealed severe vaginal hemorrhage, abdominal pain, pale mucous membranes and the presence of solid structures to abdominal palpation. A hematological test revealed a marked hemorrhagic anemia, and abdominal radiography and ultrasonographic examination showed two dead fetuses in the uterus. Median laparotomy revealed a rupture of the left uterine horn adjacent to the bifurcation, region of weakened uterine wall in the right uterine horn, blood clots and uterine fluids in abdominal cavity without septic peritonitis. The bitch underwent ovariohysterectomy and recovered without complication.

A suspension bridge is a type of bridge in which the beam is suspended by load-bearing cables. There are two classifications: the self-anchored suspension bridge has the main cable anchored to the bridge girders, and the earth-anchored suspension bridge has the main cable anchored to a large anchorage. Although a suspension bridge is structurally safe, it is prone to be damaged by various actions such as hurricanes, tsunamis and terrorist incidents because its cables are exposed. If damage to a cable eventually leads to the cable rupture, the bridge may collapse. To avoid these accidents, studies on the dynamic behavior of cable bridges due to the cable rupture have been carried out. Design codes specify that the calculated DAF (dynamic amplification factor) should not exceed a certain value. However, it has been difficult to determine DAFs effectively from dynamic analysis, and thus no systematic approach has been suggested. The current study provides a guideline to determine DAFs reliably from the dynamic analysis results and summarizes the results by applying the method to an earth-anchored suspension bridge. In the study, DAFs were calculated at the location of four structural parts, girders, pylons, main cable and hangers, with variations in the rupture time.

A 12-year-old spayed female Pomeranian (weighing 2.4 kg) was referred with primary complaints of acute dyspnea, cough, and lethargy. Diagnostic imaging studies found degenerative mitral valve cusps, chordae tendinae rupture, severe mitral regurgitation (5.45 m/s of peak velocity), and marked left atrial and ventricular dilation. The dog was diagnosed as having degenerative mitral valve disease (DMVD) with ISACHC stage IIIa heart failure. Her clinical condition was stabilized after administration of cardiac medication (e.g. diuretics and pimobendan). Ten months later, the dog was referred back to the clinic due to a sudden worsening of clinical signs. Echocardiographic study found pulmonary hypertension in addition to DMVD. After medication was adjusted, clinical signs were stabilized in 2 weeks. The patient was returned after 4 months for cardiac recheck and there was no obvious worsening of clinical signs. Incidental finding of a left-to-right atrial septal defect from rupture of the atrial septum secondary to marked left atrial dilation by DMVD was noted by echocardiography. To diminish left atrial volume overload, the frequencies of both furosemide and pimobendan were increased (i.e. from q 12 hr to q 8 hr) in addition to adding spironolactone (1 mg/kg q 12 hr). Based on diagnostic findings, this case was re-diagnosed as acquired atrial septal defect secondary to rupture of the atrial septum with advanced stage DMVD. The dog was then stabilized and is currently being regularly monitored.

췌십이지장 동맥류는 드물고 진단에 특징적인 신체 진찰소견이 없어 초기 진단이 어렵다. 이전에는 대부분이 파열과 동시에 진단되었으나, 최근 영상 검사의 발달로 우연히 발견되는 경우가 증가하고 있다. 췌십이지장 동맥류는 대부분이 파열되며, 파열시에는 치사율이 50% 에 달해 정확한 진단에 따른 치료가 중요하다. 파열시에는 혈관 조영술이 진단과 치료를 위한 좋은 검사이나, 검진 상 발견되는 경우에는 췌장종괴와의 감별 위하여 내시경 초음파가 진단에 도움을 줄 수 있다. 저자들은 복부통증을 주소로 내원하여 췌십이지장 동맥류를 전산화 단층촬영과 내시경 초음파를 통해 파열 전 진단하고 경피적 동맥색전술로 후유증 없이 치료한 1 예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

Technological mode progress demands the use of materials at high temperature and pressure. Constant load creep tests have been carried out over the range of stresses at high temperatures. One of the most critical factors in considering such applications as the most critical one is the creep behavior. In order to investigate the creep behavior in this study, the stress exponents during creep were determined over the temperature range of 275℃ to 325℃ and the stress range of 36MPa to 72MPa. The applicability of modified Monkman-Grant relationship was also discussed.

본 연구에서는 실린더 형 쉘 구조물의 구조적 안정성에 대하여 해석 하였다. 임계하중은 하중을 점차적으로 증가 하여 구조물이 파괴가 발생 할 때의 상태에서 가장 작은 하중을 의미한다. 셀 구조의 안정성을 임계하중의 크기로 기초를 두고 해석 하였다. 실린더 형 쉘의 차분해석은 일차적 원통형 판구조와 같으므로 최근에 많은 연구의 대상이 되어왔다. 차분법은 복잡한 구조물에서도 물론, 다양한 경계조건을 포함하는 문제에 이르기까지 효과적인 수치방법이다. 본 연구에