• Archives of Plastic Surgery
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• v.47 no.3
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• pp.263-266
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• 2020

Infantile hemangiomas have a growth phase and an involution phase. For this reason, serial observation has generally been recommended as the treatment for uncomplicated infantile hemangiomas. Recently, however, individualized approaches have been emphasized. Although cleft lip and infantile hemangioma are common congenital diseases, infantile hemangiomas on the cleft side (i.e., in the operative field of the cleft lip) are extremely rare, and no clear guidelines have been established for their treatment. We experienced a case in which a patient with a cleft lip had an infantile hemangioma on the cleft side. In accordance with general treatment guidelines, cleft repair was performed 3 months after birth. The Millard rotation-advancement technique, which involves the use of a lower small triangular flap, was used for the repair. No intraoperative complications, such as massive bleeding, or postoperative complications were noted. The patient has received regular follow-up for the past 18 years, and other than a reddish scar on the lower lip, he currently has no related issues. Therefore, this case demonstrates that cleft lip repair performed according to cleft lip treatment guidelines produces good outcomes, even in cases involving a hemangioma on the cleft side.

• Archives of Plastic Surgery
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• v.47 no.3
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• pp.277-280
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• 2020

Functionally, the lip serves to prevent food and drink from spilling out of the beginning of the gastrointestinal tract, and it is also used for vocalization. In addition, the lip has cosmetic importance as part of the face involved in making expressions, and in many cultures, it is considered to be sexually appealing. The results of lip reconstruction procedures must therefore be both functionally and cosmetically satisfactory. When the orbicularis oris muscle and oral mucosa are excised, functional reconstruction is prioritized. In contrast, if there are no functional problems, cosmetic reconstruction is the main focus. This case involved the reconstruction of a right upper lip defect caused by a dog bite. When the skin defect was covered with a local flap, the right angulus oris shifted medially, so we incorporated a YV flap at the right angulus oris to modify its position and allow for a cosmetically satisfactory result. We believe that this method can be used not only for cases in which asymmetry of the angulus oris is expected to occur at the time of lip reconstruction, but also for cases in which it has already occurred in the initial operation.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.145-156
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• 1993

An improved analysis model for material nonlinearity induced by elasto-plastic deformation and damage including large strain response was proposed. The elasto-plastic-damage constitutive model based on the continuum damage mechanics approach was adopted to overcome limitations of the conventional plastic theory, which can manage the anisotropic tonsorial damages evolved during time-independent plastic deformation process of materials. Updated Lagrangian finite element formulation for elasto-plastic damage coupling problem including large deformation, large rotation and large strain problems was completed to develop a numerical model which can predict all kinds of structural nonlinearities and damage rationally. Finally, a finite element analysis code for the 2-dimensional plane problem was developed and the applicability and validity of the numerical model was investigated through some numerial examples. Calculations showed reasonable results in both geometrical nonlinear problem due to large deformation and material nonlinearity including the damage effect.

• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.535-546
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• 2011

In this paper, semi-rigid elasto-plastic post-buckling analysis of a space frame was performed using various explicit arc-length methods. Various explicit arc-length methodsand a large-deformation and small-strain elasto-plastic 3D space frame element with semi-rigid connections and plastic hinges were developed. This element can be appliedto both explicit and implicit numerical algorithms. In this study, the Dynamic Relaxation method was adopted in the predictor and corrector processesto formulate an explicit arc-length algorithm. The developed "explicit-predictor" or "explicit-corrector" were used in the elasto-plastic post-buckling analysis. The Eulerian equations for a beam-column with finite rotation, which considers the bowing effects, were adopted for the elastic system and extended to theinelastic system with a plastic hinge concept. The derived tangent stiffness matrix was asymmetrical due to the finite rotation. The joint connection elements were introduced for semi-rigidity using a static condensation technique. Semi-rigid elasto-plastic post-buckling analyses were carried out to demonstrate the potential of the developed explicit arc-length method and advanced space frame element in terms of accuracy and efficiency.

• Steel and Composite Structures
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• v.18 no.4
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• pp.873-887
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• 2015

The continuous composite I-girder should have a sufficient rotation capacity (or ductility) to redistribute the negative bending moment into an adjacent positive bending moment region. However, it is generally known that the ductility of the high strength steel is smaller than that of conventional steel, and application of high strength steel can cause ductility problems in a negative moment region of the I-girder. In this study, moment redistribution of the continuous composite I-girder with high strength steel was studied, where high strength steel with yield stress of 690 MPa was considered (the ultimate stress of the steel was 800 MPa). The available and required rotation capacity of the continuous composite I-girder with high strength steel was firstly derived based on the stress-strain curve of high strength steel and plastic analysis, respectively. A large scale test and a series of non-linear finite element analysis for the continuous composite I-girder with high strength steel were then conducted to examine the effectiveness of proposed models and to investigate the effect of high strength steel on the inelastic behavior of the negative bending moment region of the continuous composite I-girder with high strength steel. Finally, it can be found that the proposed equations provided good estimation of the requited and available rotation capacity of the continuous composite I-girder with high strength steel.

• Earthquakes and Structures
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• v.14 no.3
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• pp.241-248
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• 2018

To study the mechanical properties of joints in ancient timber buildings in depth, the force mechanism of the through-tenon joints was analyzed, also the theoretical formulas of the moment-rotation angles of the joints with different loosening degrees were deduced. To validate the rationality of the theoretical calculation formulas, six joint models with 1/3.2 scale ratio, including one intact joint and five loosening joints, were fabricated and tested under cyclic loading. The specimens underwent the elastic stage, the plastic stage and the destructive stage, respectively. At the same time, the moment-rotation backbone curves of the tenon joints with different looseness were obtained, and the theoretical calculation results were validated when compared with the experimental results. The results show that the rotational moment and the initial rotational stiffness of the tenon joints increase gradually with the increase of the friction coefficient. The increase of the tenon section height can effectively improve the bearing capacity of the through-tenon joints. As the friction coefficient of the wood and the insertion length of the tension increase, the embedment length goes up, whereas it decreases with the increase of section height. With the increase of the looseness, the bearing capacity of the joint is reduced gradually.

• Steel and Composite Structures
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• v.12 no.5
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• pp.395-412
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• 2012

The present work addresses the rotational capacity of steel-concrete composite beams, which is a key issue for the seismic design of composite frames. Several experimental tests from the literature are summarised, and the effects of various parameters on the available plastic rotation are discussed. Furthermore, a number of remarks are made regarding the need for supplementary experimental results. The authors carried out experimental tests on four composite beams in which the type, width and connection degree of the slab were varied. During the tests, the deflection and strains in the steel profiles and bars were measured and recorded, wherein the observed trends in the measured parameters indicated that the failure mode of the beam was influenced by global and local buckling. A comparison of the experimental results to the theoretical ultimate strengths and moment-curvature relationships confirms that buckling phenomena occurred after section yielding, even if a consistent plastic rotation developed. This rotational capacity is well evaluated by a formulation that is available in the literature.

• Steel and Composite Structures
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• v.26 no.5
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• pp.621-634
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• 2018

Flush end-plate (FEP) beam-to-column joints are commonly used for gravity load resisting parts in steel multi-storey buildings. However, in seismic resisting structures FEP joints should also provide rotation capacity consistent with the global structural displacements. The current version of EN1993-1-8 recommends a criterion aiming at controlling the thickness of the end-plate in order to avoid brittle failure of the connection, which has been developed for monotonic loading conditions assuming elastic-perfectly plastic behaviour of the connection's components in line with the theory of the component method. Hence, contrary to the design philosophy of the hierarchy of resistances implemented in EN1998-1, the over strength and the hardening of the plastic components are not directly accounted for. In light of these considerations, this paper describes and discusses the results obtained from parametric finite element simulations aiming at investigating the moment-rotation response of FEP joints under cyclic actions. The influence of bolt diameter, thickness of end-plate, number of bolt rows and shape of beam profile on the joint response is discussed and design requirements are proposed to enhance the ductility of the joints.

• Steel and Composite Structures
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• v.23 no.1
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• pp.53-66
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• 2017

Structures submitted to Fire-After-Earthquake loading situations, are first experiencing inelastic deformations due to the seismic action and are then submitted to the thermal loading. This means that in the case of steel framed structures, at the starting point of the fire, plastic hinges have already been formed at the ends of the beams. The basic objective of this paper is the evaluation of the rotational capacity of steel I-section beams damaged due to prior earthquake loading, at increased temperatures. The study is conducted numerically and three-dimensional models are used in order to capture accurately the nonlinear behaviour of the steel beams. Different levels of earthquake-induced damage are examined in order to study the effect of the initial state of damage to the temperature-evolution of the rotational capacity. The study starts with the reference case where the beam is undamaged and in the sequel cyclic loading patterns are taken into account, which represent earthquakes loads of increasing magnitude. Additionally, the study extends to the evaluation of the ultimate plastic rotation of the steel beams which corresponds to the point where the rotational capacity of the beam is exhausted. The aforementioned value of rotation can be used as a criterion for the determination of the fire-resistance time of the structure in case of Fire-After-Earthquake situations.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.928-937
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• 1989

Applicability of $T_{\delta}$ proposed by Shin et al as an instability parameter for ductile material is investigated, Both general fracture test and instability fracture test are performed using compact tension specimens of structural alloy steel(SCM4), The values of ( $T_{\delta}$)$_{app}$(applied tearing modules) estimated from the real load vs. crack growth curve measured from experiments are compared with those estimated from the limit load vs. crack growth curve. The results are:(1) the $T_{\delta}$ parameter may be used as a crack instability parameter:(2) the use of ( $T_{\delta}$)$_{app}$ estimated from the load-crack growth curve, proposed in this study is reasonably justified.ified.d.