• Steel and Composite Structures
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• v.47 no.3
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• pp.375-382
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• 2023

The H-shaped steel beam is popular due to its ease of manufacturing and connection to the column. This profile, which is used as a shallow beam, needs the high weak-axis bending stiffness and torsional stiffness to meet the overall stability. Achieving the local beam flange stability, bearing capacity, bending stiffness, and torsional requirements need a great thickness and width of the beam flange, which causes, which will cause more uneconomical structural design. So, the box-section beam is the ideal alternative. However, the current design specifications do not have design rules for the bolt-and-welded connection of the box-section beam and box-section column. The paper proposes a novel bolt-and-welded connection of the box-section beams and box-section columns based on a high-rise structural design scheme. Three connection models, BASE, WBF, and RBS, are analyzed under cyclic loading in ABAQUS software. The failure modes, hysteresis response, bearing capacity, ductility, plastic rotation angle, energy dissipation, and stiffness degradation of all models are determined and compared. Compared with the other two models, the model WBF exhibited excellent seismic performance, ductility, and plastic rotation ability. Finally, model WBF was chosen as the connection scheme used in the project design.

• Steel and Composite Structures
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• v.8 no.1
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• pp.85-98
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• 2008

In this study the progressive collapse potential of three- and nine-story special steel moment frames designed in accordance with current design code was evaluated by nonlinear static and dynamic analyses. It was observed that the model structures had high potential for progressive collapse when a first story column was suddenly removed. Then the size of beams required to satisfy the failure criteria for progressive collapse was obtained by the virtual work method; i.e., using the equilibrium of the external work done by gravity load due to loss of a column and the internal work done by plastic rotation of beams. According to the nonlinear dynamic analysis results, the model structures designed only for normal load turned out to have strong potential for progressive collapse whereas the structures designed by plastic design concept for progressive collapse satisfied the failure criterion recommended by the GSA guideline.

• Transactions of Materials Processing
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• v.4 no.4
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• pp.365-374
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• 1995

Numerical simulation of blade forming is carried out as stretch forming by an elasto-plastic finite element method. The method adopts a Lagrangian formulation, which incorporates large deformation and rotation, with a penalty method to treat the contact boundary condition. Numerical integration is done with a directional reduced integration scheme to avoid shear locking. The numerical results demonstrates various final shapes of blades which depend on the variation of the stretching force. The strain distributions in deformed blades are also obtained with the variation of the stretching force.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.385-388
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• 2006

The purpose of this study is to offer an appropriate method of the degree of the flexural moment redistribution for continuous reinforced concrete beams. Twenty-four two-span continuous beams were selected to determine the manner and degree of moment redistribution. The concept of ductility is linked to the moment redistribution capacity and, consequently, the safety of the structure. Knowledge of the plastic rotation capacity of plastic regions of the structure is important for a plastic analysis or a linear analysis with moment redistribution. A nonlinear finite element analysis program named RCAHEST (Reinforced Concrete Analysis in Higher Evaluation System Technology) was used to evaluate the ultimate strength and degree of moment redistribution. The nonlinear material model for the reinforced concrete is composed of models for characterizing the behavior of the concrete, in addition to a model for characterizing the reinforcing bars.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.422-426
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• 1992

One case of Congenital Cutis Aplasia is presented. The defect involved includes full-thickness skin defect of scalp and cranium. The patient was treated with debridement of dirty necrosed crust which covered exposed dura mater and with double opposing rotation flap including pericranium for bone regneration. The donor site was covered with skin graft from right thigh. During operation, the superficial temporal arterty was found to be short and weak. And after operation, the margin of flap were congested and finally necrotized. The necrotic wound was treated with conservative management. The vascular impairment is thought to be main course of Congenital Cutis Aplasia. So we conclude that the treatment of choice is conservative management or careful flap surgery for coverage of defect area.

• Archives of Plastic Surgery
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• v.32 no.1
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• pp.105-109
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• 2005

Perineal area is composed of compact structures of urogenital organs and anus requiring a more sophisticated selection of flap and reconstruction. For achieving better outcome then conventional flap surgery, we use the perineal perforator based island flap for its reconstruction. After locating the perforator by Doppler, the flaps were designed according to the defect or expected vaginal orifice. The flaps were elevated bilaterally as island pattern. Finally defect or neovagina was reconstructed with inconspicious linear scar hidden in the inguinal crease. Five cases were performed with the perineal perforator based island flap. There were 3 cases of vulvar cancer, 1 case of transsexualism, and 1 case of ambiguous genitalia because of congenital adrenal hyperplasia. Operative results were satisfactory with good contouring and less prominent donor scar, when they were compared with other flap reconstructions such as latissimus dorsi perforator flap, groin flap, gracilis myocutaneous flap etc. The perineal perforator based island flap is highly recommended with the advantages of easy flap elevation, good rotation arc, and appropriate flap thickness for contouring. Compared with other conventional flaps, it can be selected as a good option for moderate defect of perineal area.

• Archives of Plastic Surgery
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• v.40 no.5
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• pp.616-620
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• 2013

Background Nasal tip support is an essential consideration for rhinoplasty in East Asians. There are many techniques to improve tip projection, and among them, the columellar strut is the most popular technique. However, the conventional design is less supportive for rotating the tip. The amount of harvestable septal cartilage is relatively small in East Asians. For an optimal outcome, we propose an L-shaped design for applying the columellar strut. Methods To evaluate the anthropometric outcomes, the change in nasal tip projection and the columella-labial angle were analyzed by comparing preoperative and postoperative photographs. The anthropometric study group consisted of 25 patients who underwent the same operative technique of an L-shaped strut graft using septal cartilage and were followed up for more than 9 months. Results There were statistically significant differences between the preoperative and postoperative values in the nasal tip projection ratio and columella-labial angle. We did not observe any complications directly related to the L-shaped columellar strut in the anthropometric study group. Conclusions The L-shaped columellar strut has advantages not only in the controlling of tip projection and rotation, but in that it needs a smaller amount of cartilage compared to the conventional septal extension graft. It can therefore be an alternative technique for nasal tip plasty when there is an insufficient amount of harvestable septal cartilage.

• Steel and Composite Structures
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• v.2 no.1
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• pp.21-34
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• 2002

A model of the process of local buckling in tubular steel structural elements is presented. It is assumed that this degrading phenomenon can be lumped at plastic hinges. The model is therefore based on the concept of plastic hinge combined with the methods of continuum damage mechanics. The state of this new kind of inelastic hinge is characterized by two internal variables: the plastic rotation and the damage. The model is valid if only one local buckling appears in the plastic hinge region; for instance, in the case of framed structures subjected to monotonic loadings. Based on this damage model, a new finite element that can describe the development of local buckling is proposed. The element is the assemblage of an elastic beamcolumn and two inelastic hinges at its ends. The stiffness matrix, that depends on the level of damage, the yielding function and the damage evolution law of the two hinges define the new finite element. In order to verify model and finite element, several small-scale frames were tested in laboratory under monotonic loading. A lateral load at the top of the frame was applied in a stroke-controlled mode until local buckling appears and develops in several locations of the frame and its ultimate capacity was reached. These tests were simulated with the new finite element and comparison between model and test is presented and discussed.

• Archives of Aesthetic Plastic Surgery
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• v.23 no.3
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• pp.143-145
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• 2017

Medical leech therapy is a treatment for the venous congestion of tissue flaps, grafts, and replants. We report a case of methicillin-resistant Staphylococcus aureus (MRSA) following leech application at a congested flap after mastectomy. A 45-year-old woman had an invasive ductal carcinoma. Modified radical mastectomy was performed. The chest wall defect was reconstructed with a local rotation flap. On postoperative day (POD) 1, congestion and color change were observed, and 10 medical leeches were applied to the congested area. On POD 4, another 10 medical leeches were applied. On POD 12, wound necrosis progressed and a pus-like discharge appeared. A wound swab culture revealed MRSA. Debridement was carried out on POD 15. From POD 16, vancomycin and piperacillin/tazobactam were injected for 18 days. The wound culture on POD 18 also revealed MRSA. A split-thickness skin graft was performed on POD 28. MRSA has not been clearly identified in the literature as a leech enteric bacterium. Although MRSA may have come from another source, the present case raises the possibility of MRSA infections following leech application at congested flaps. When medical leeches are applied at the congestion site of a flap, an aseptic cradle will be helpful. Vancomycin irrigation may be needed if infection occurs.

• Archives of Craniofacial Surgery
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• v.22 no.6
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• pp.341-344
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• 2021

Reconstruction of submental defects is a challenge that needs to be approached carefully, since many important anatomical structures are located in this small space. Both aesthetic and functional outcomes should be considered during reconstruction. In this report, we describe a case where a superficial branch of the transverse cervical artery (STCA) perforator propeller flap was applied for coverage of the submental area. An 85-year-old woman presented with a 3-cm ovoid mass on her submental area. We covered the large submental defect with a STCA rotational flap in a 180° propeller pattern. The flap survived well without any complications at 1 year of followup. A STCA propeller flap is a useful surgical option in reconstruction for defect coverage of the submental area.