• Composites Research
• /
• v.26 no.4
• /
• pp.223-229
• /
• 2013

Hybrid composite strut tower was designed to prevent permanent deformation of upper mount by the impact from the uneven road. When exceeding energy absorption capacity of tire and suspension systems, residual impact is delivered to upper mount. Especially, in case of using high-rigidity suspension system for high driving performance, the conventional strut tower can be easily deformed due to reduction of energy absorption capacity of suspension systems. In this study, optimal design of hybrid composite strut tower which made of back-up metal and carbon fiber reinforced composite was suggested by using finite element analysis, and low velocity impact test was performed to investigate their dynamic characteristics. Also, 3D measuring and ultra c-scanning methods were carried out to diagnose damages in the strut towers.

• Structural Engineering and Mechanics
• /
• v.27 no.4
• /
• pp.501-521
• /
• 2007

This study presents a model to better understand the shear behavior of reinforced concrete walls subjected to lateral load. The scope of the study is limited to squat walls with height to length ratios not exceeding two, deformed in a double-curvature shape. This study is based on limited knowledge of the shear behavior of low-rise shear walls subjected to double-curvature bending. In this study, the wall ultimate strength is defined as the smaller of flexural and shear strengths. The flexural strength is calculated using a strength-of-material analysis, and the shear strength is predicted according to the softened strut-and-tie model. The corresponding lateral deflection of the walls is estimated by superposition of its flexibility sources of bending, shear and slip. The calculated results of the proposed procedure correlate reasonably well with previously reported experimental results.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2005.05a
• /
• pp.95-98
• /
• 2005

The objective of this experimental study was to understand the structural behavior of reinforced concrete continuous deep beams with welded deformed wire fabric(WWF) as shear reinforcement. The structural behavior of deep beams reinforced with WWF was compared with that of deep beams reinforced with orthogonal shear reinforcement which had standard anchorage corresponding to ACI 318-02. Test results showed that the load transferring capacity and the control of splitting cracks in the strut of WWF were almost as effective as those of orthogonal shear reinforcement with standard anchorage.

• Journal of Chest Surgery
• /
• v.18 no.3
• /
• pp.492-496
• /
• 1985

Two cases of surgical correction of funnel chest using metal struts were presented. The main procedures of the method were transverse submammary incision, subperichondrial resection of the deformed costal cartilages, division of the xiphisternal joint, wedge osteotomy of the sternum, freeing of the posterior surface of the sternum and stabilization by means of 2 metal struts. The struts were removed postoperative 3 and 6 months by a small incision under the local anesthesia. The results in both patients were satisfactory. This method of correction is simple, easy to perform and free of any operative risks.

• Journal of Chest Surgery
• /
• v.7 no.2
• /
• pp.153-162
• /
• 1974

Four patients with funnel chest deformity corrected in the Department of Thoracic Surgery, Seoul National University Hospital are presented. The first case was a 21-year old female with cyanosis, clubbed fingers and systolic murmur on the left infrascapular region on physical examination associated with agenesis of the right lung. The deformity was of asymmetrical funnel chest, in which the left hemithorax was more sunken. She was corrected by the method of Funnel Costoplasty of Wada. The second case was a three years old boy whose anterior chest wall was symmetrically deformed, and he was corrected by the method of Ravitch using Adkins strut under the sternum. The third was a 22-year old man with symmetrical deformity, and was corrected by the method described by Shannon in 1973. The last patient was a 22-year old man and he had dyspnea on exertion, palpitation and apical systolic murmur with symmetrical funnel chest deformity. He was also corrected by Ravitch operation, All of them has excellent result.

• Journal of Chest Surgery
• /
• v.19 no.3
• /
• pp.391-398
• /
• 1986

From Jan. 1983 to Dec. 1985, seven cases of pectus excavatum, six were male and one female, were underwent an operation at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University Hospital. The ages of patients ranged from 6 to 27 years. They all had symptoms of feeling inferiority about chest deformity. The concavity on the funnel chest varied in its extent, and the severity, which was measured by water volume filled into it, varied from 59.5cc/m2 to 129.9cc/m2. All but one patients were approached through a bilateral transverse submammary incision and one approached through a vertical midline incision. Successful surgical correction required resection of all deformed costal cartilages with transverse anterior osteotomy and internal fixation using retrosternal metal bar. No serious complication have followed the use of this technique, but minor complications such as serous accumulation, pneumothorax and strut migration have been experienced. All patients were satisfactory about the surgical results.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.20 no.3
• /
• pp.593-608
• /
• 2018

If a problem occurs in the strut during the construction of the braced wall, they may cause excessive deformation of the braced wall. Therefore, in this study, the behavior of the braced wall and existing tunnel adjacent to excavation were investigated assuming that the support function of strut is lost during construction process. For this purpose, a series of model test was performed. As a result of the study, the earth pressure in the ground behind wall was rearranged due to the deformation of the braced wall, and the ground displacements caused the deformation of adjacent tunnels. When the struts located on the nearest side wall from the tunnel were removed, the deformation of the braced wall and the tunnel deformation were the largest. The magnitude of transferred earth pressure depended on the location of tunnel. The increase of the cover depth of tunnel from 0.65D to 2.65D caused the increase of the earth pressure by 25.6%. As the distance between braced wall and tunnel was increased from 0.5D to 1.0D, the transferred earth pressure increased by 16% on average. Horizontal displacements of braced wall by the removal of the strut tended to concentrate around the removed struts, and the horizontal displacement increased as the strut removal position is lowered. The tunnel displacement was maximum, when the cover depth of tunnel was 1.15D and the horizontal distance between braced wall and the side of tunnel was 0.5D. The minimal displacement occurred, when the cover depth of tunnel was 2.65D and the horizontal distance between braced wall and the side of tunnel was 1.0D. The difference between the maximum displacement and the minimum displacement was about 2 times, and the displacement was considered to be the largest when it was in the range of 1.15D to 1.65D and the horizontal distance of 0.5D.