• Journal of Trauma and Injury
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• 제37권1호
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• pp.48-59
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• 2024

Purpose: Research on rib fracture management has exponentially increased. Predicting fracture patterns based on the mechanism of injury (MOI) and other possible correlations may improve resource allocation and injury prevention strategies. The Chest Injury International Database (CIID) is the largest prospective repository of the operative and nonoperative management of patients with severe chest wall trauma. The purpose of this study was to determine whether the MOI is associated with the resulting rib fracture patterns. We hypothesized that specific MOIs would be associated with distinct rib fracture patterns. Methods: The CIID was queried to analyze fracture patterns based on the MOI. Patients were stratified by MOI: falls, motor vehicle collisions (MVCs), motorcycle collisions (MCCs), automobile-pedestrian collisions, and bicycle collisions. Fracture locations, associated injuries, and patient-specific variables were recorded. Heat maps were created to display the fracture incidence by rib location. Results: The study cohort consisted of 1,121 patients with a median RibScore of 2 (range, 0-3) and 9,353 fractures. The average age was 57±20 years, and 64% of patients were male. By MOI, the number of patients and fractures were as follows: falls (474 patients, 3,360 fractures), MVCs (353 patients, 3,268 fractures), MCCs (165 patients, 1,505 fractures), automobile-pedestrian collisions (70 patients, 713 fractures), and bicycle collisions (59 patients, 507 fractures). The most commonly injured rib was the sixth rib, and the most common fracture location was lateral. Statistically significant differences in the location and patterns of fractures were identified comparing each MOI, except for MCCs versus bicycle collisions. Conclusions: Different mechanisms of injury result in distinct rib fracture patterns. These different patterns should be considered in the workup and management of patients with thoracic injuries. Given these significant differences, future studies should account for both fracture location and the MOI to better define what populations benefit from surgical versus nonoperative management.

• 비파괴검사학회지
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• 제19권1호
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• pp.25-33
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• 1999

콘크리트는 다상(multi-phase)의 재료로서 구성되어지는 복합재료의 일종으로써 준취성(quasi-brittle)적인 재료적 특성을 가지고 있기 때문에 실제 복잡한 미시적 파괴특성을 나타낸다. 따라서 콘크리트 구조물의 안전성 확보를 위해서는 먼저 하중의 증가에 따른 콘크리트 내부의 변형특성 및 미시적 파손기구를 파악하여야 하며, 특히 실제 구조물에 있어서는 이들 특성들을 비파괴적으로 상시 (on-line) 모니터링 하여야 할 필요가 있다. 따라서 본 연구에서는 3점 굽힘 하중을 받는 콘크리트 부재의 미시적 파손기구 및 각 파손기구에 대한 AE 특성을 명확히 함으로써 콘크리트 부재의 미시적 손상 및 파괴 특성을 비파괴적으로 평가하고 AE 발생원 위치 추정 기법을 이용하여 균열 발생 및 진전거동을 평가하였다.

• 대한두개안면성형외과학회지
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• 제18권2호
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• pp.92-96
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• 2017

Background: All nasal bone fractures have the potential for worsening of olfactory function. However, few studies have studied the olfactory outcomes following reduction of nasal bone fractures. This study evaluates posttraumatic olfactory dysfunction in patients with nasal bone fracture before and after closed reduction. Methods: A prospective study was conducted for all patients presenting with nasal bone fracture (n=97). Each patient consenting to the study underwent the Korean version of Sniffin' Sticks test (KVSS II) before operation and at 6 month after closed reduction. The nasal fractures were divided according to the nasal bone fracture classification by Haug and Prather (Types I-IV). The olfactory scores were compared across fracture types and between preoperative and postoperative settings. Results: Olfactory dysfunction was frequent after nasal fracture (45/97, 46.4%). Our olfactory assessment using the KVSS II test revealed that fracture reduction was not associated with improvements in the mean test score in Type I or Type II fractures. More specifically, the mean posttraumatic Threshold, discrimination and identification score decreased from 28.8 points prior to operation to 23.1 point at 6 months for Type II fracture with septal fracture. Conclusion: Our study has revealed two alarming trends regarding post-nasal fracture olfactory dysfunction. First, our study demonstrated that almost half (46.4%) of nasal fracture patients experience posttraumatic olfactory dysfunction. Second, closed reduction of these fractures does not lead to improvements olfaction at 6 months, which suggest that olfactory dysfunction is probably due to factors other than the fracture itself. The association should be further explored between injuries that lead to nasal fracture and the mechanism behind posttraumatic olfactory dysfunction.

• 대한기계학회논문집A
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• 제20권3호
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• pp.806-815
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• 1996

The interlaminar fracture behavior of woven laminates under static and cyclic loadings has been studied using DCB(double cantilever beam) specimens. The effects of surface treatment and stiching on the fracture behavior of composite laminates are investigated experimentally. Fracture toughness has been improved by surface treatment because the surface treatment can change the fracture mechanism of laminates. SCB(stitched cantilever beam) model has been proposed to quantify the effect of through-thickness resinforcement(stiching) in improving the delamination crack growth resistance. Distributed loads which are transfered to through-thickness fibers can be calculated by the SCB model. And fracture energy increase due to the distributed load can be predicted by a power function of the distributed load. A new parameter agreed well proposed predict fatigue crack growth rate. The predictions using this parameter agreed well with the experimental data.

• 수산해양기술연구
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• 제39권3호
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• pp.167-173
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• 2003

Many of researches regarding mechanical properties of composite materials are associated with humid environment and temperature. Especially the temperature is a very important factor influencing the design of thermoplastic composites. However, the effect of temperature on impact behavior of reinforced composites have not yet been fully explored. An approach which predicts critical fracture toughness G$_{IC}$ was performed by the impact test in this work. The main goal of this work is to study the effect of temperature and span of specimen supports on the results of Charpy impact test for GF/PE composite. The critical fracture energy and failure mechanism of GF/PE composites were investigated in the temperature range of $60^{\circ}C;to;-50^{\circ}C$ by the Charpy impact test. The critical fracture energy showed the maximum at the ambient temperature, and it tended to decrease as the temperature increased or decreased from the ambient temperature. The major failure mechanisms are the fiber matrix debonding, the fiber pull-out and/or delamination and the matrix deformation.n.

• 한국해양공학회지
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• 제10권4호
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• pp.75-83
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• 1996

Polymeric composites can be subjected to a wide variety of environmemtal conditions in practical use. One of most important conditions to be considered in the stuctural design using such materials is the miisture envirnment. Thus the moisture effect on interlaminar fracture toughness $G_IC$ and $G_IIC$ of CFRP(carbon fiber reinforced plastic) composed of carbon fibers and epoxy resin is studied in this paper. Specimens were first processed in 25, 50, $80^{\circ}C$ flesh water and $25^{\circ}C$ sea water for various periods of time. After that, the water absorption and fracture toughness tests were performed under laboratory atmosphere. As result, the specimen processed in $80^{\circ}C$ flesh water indicates the highest misture absorbing capability, the second in $50^{\circ}C$ flesh water, the third in $25^{\circ}C$ sea water, and the specimen in $25^{\circ}C$ flesh water does the lowest. The interlaminar fracture toughness $G_IC$ increases, approaches to the maximum, and decreases as the immersion time increases. In case of interlaminar $G_IIC$, the value of the specimen processed in $80^{\circ}C$ flesh water turns out to be higher than others. In addition, the scanning electron micrographs(SEM) of fracture surfaces were also examined in order to explain the mechanism of fracture.

• 선박안전
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• 통권25호
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• pp.64-76
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• 2008

This paper describes the failure mechanism and Charpy impact test of Fiber glass Reinforced Plastic composites which it was actually used for side plate of vessel. There are two examinations. The examination I, the specimens which it given temperature range $-25^{\circ}C$-$50^{\circ}C$ and with different initial notch length did impact test and then it compared impact energy(Uc) and impact fracture toughness(GIC). The examination II, the specimens which it putted into fresh water and sea water for scheduled hours did impact test and it compared impact energy(Uc) and impact fracture toughness(GIC). From examination I, it showed that impact energy(Uc) and impact fracture toughness(GIC) were peak at ambient temperature and decrease as temperature reduced. Fracture toughness(GIC) showed increase as initial notch length reduced. From examination II, impact energy(Uc) and impact fracture toughness(GIC) tended to increase which specimens putted in fresh water compared with sea water and maximum tolerance rate tend to decrease as permeation hours will be long.

• 대한금속재료학회지
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• 제47권1호
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• pp.50-58
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• 2009

In this study, alumina matrix composites reinforced with carbon nanotubes (CNTs) were fabricated by ultrasonic dispersion, ball milling, mixing, compaction, and sintering processes, and their relative density, electrical resistance, hardness, flexure strength, and fracture toughness were evaluated. 0~3 vol.% of CNTs were relatively homogeneously dispersed in the composites in spite of the existence of some pores. The three-point bending test results indicated that the flexure strength increased with increasing volume fraction of CNTs, and reached the maximum when the CNT fraction was 1.5 vol.%. The fracture toughness increased as the CNT fraction increased, and the fracture toughness of the composite containing 3 vol.% of CNTs was higher by 40% than that of the monolithic alumina. According to observation of the crack propagation path after the indentation fracture test, a new toughening mechanism of grain interface bridging-induced CNT bridging was suggested to explain the improvement of fracture toughness in the alumina matrix composites reinforced with CNTs.

• Journal of Trauma and Injury
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• 제26권3호
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• pp.125-130
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• 2013

Purpose: This study was undertaken in order to identify the characteristics of patients diagnosed with occult an hip fracture after hip trauma. Methods: We retrospectively reviewed the medical records and radiology reports of all patients who underwent hip skeletal computed tomography (CT) for suspected hip fractures but had normal initial X-rays after hip trauma between August 2006 and January 2012. The variables evaluated included age, gender, body mass index (BMI), accident mechanism, previous fracture, independence, late presentation, ability to bear weight, pain on passive rotation, tenderness of the groin area, diagnosis and treatment. Patients were divided into two groups, with hip fracture (occult hip fracture group) and without hip fracture (no fracture group) to evaluate the characteristics associated with an occult hip fracture. Results: The patients, a total of 139, had a mean age of 58.3 years and included 72 male patients(51.8%). The occult hip fracture group included 43 patients(30.9%). Of those 43, 21 patients(48.8%) had intertrochanteric or trochanteric fractures, 8 patients(18.6%) had femur neck fractures and 14 patients(32.6%) had acetabular fractures. Of the 43, 15 patients(34.9%) needed operative treatment. Age was higher in the occult hip fracture group than it was in the no fracture group($64.4{\pm}19.1$ years vs. $55.5{\pm}23.6$ years, p=0.021). A previous fracture was associated with the presence of a new fracture (p=0.014; OR=3.971, 95% CI=1.314-11.997). Conclusion: Further evaluation of patients who are older or have history of fractures is prudent, even though the initial X-rays are normal.

• 대한두개안면성형외과학회지
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• 제21권5호
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• pp.294-300
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• 2020

Background: Mandibular fractures are one of the most common types of facial fractures, the treatment of which can be delayed due to the severity of the trauma resulting in an increase of complications; thus, early evaluation of trauma severity at the time of visit is important. In South Korea, trauma patients are triaged and intensively treated in designated regional trauma centers. This study aimed to analyze the relationship between trauma severity and mandibular fracture patterns. Methods: A medical records review was performed on patients who visited the regional trauma center at our hospital for mandibular fracture between 2009 and 2018. Epidemiologic data and mandibular fracture patterns were analyzed and compared with the conventional facial injury severity scale (FISS). Results: Among 73 patients, 51 were classified as non-severe trauma patients and 22 as severe trauma patients. A higher trauma severity was associated with older age (odds ratio [OR], 1.164; 95% confidence interval [CI], 1.057-1.404) and lower risk was associated with fractures located in the angle (OR, 0.001; 95% CI, 0-0.022), condylar process (OR, 0.001; 95% CI, 0-0.28), and coronoid process (OR, 0.004; 95% CI, 0-0.985). The risk was lower when the injury mechanism was a pedestrian traffic accident (OR, 0.004; 95% CI, 0-0.417) or fall (OR, 0.004; 95% CI, 0-0.663) compared with an in-car traffic accident. Higher FISS (OR, 1.503; 95% CI, 1.155-2.049) was associated with a higher trauma severity. The proposed model was found to predict the trauma severity better than the model using FISS (p< 0.001). Conclusion: Age, location of mandibular fractures, and injury mechanism showed significant relationships with the trauma severity. Epidemiologic data and patterns of mandibular fractures could predict the trauma severity better than FISS.