• Steel and Composite Structures
• /
• 제27권1호
• /
• pp.75-87
• /
• 2018

This paper presents a new method to compute the shear strength of composited structural B-C-W members. These B-C-W members, defined as concrete-filled steel box beams, columns and shear walls, consist of a slender rectangular steel plate box filled with concrete and inserted steel plates connecting the two long-side steel plates. These structural elements are intended to be used in structural members of super-tall buildings and nuclear safety-related structures. The concrete confined by the steel plate acts to be in a multi-axial stressed state: therefore, its shear strength was calculated on the basis of a concrete's failure criterion model. The shear strength of the steel plates on the long sides of the structural element was computed using the von Mises plastic strength theory without taking into account the buckling of the steel plate. The spacing and strength of the inserted plates to induce plate yielding before buckling was determined using elastic plate theory. Therefore, a predictive method to compute the shear strength of composited structural B-C-W members without considering the shear span ratio was obtained. A coefficient considering the influence of the shear span ratio was introduced into the formula to compute the anti-lateral bearing capacity of composited structural B-C-W members. Comparisons were made between the numerical results and the test results along with this method to predict the anti-lateral bearing capacity of concrete-filled steel box walls. Nonlinear static analysis of concrete-filled steel box walls was also conducted by using ABAQUS and the results agreed well with the experimental data.

• Steel and Composite Structures
• /
• 제32권5호
• /
• pp.571-582
• /
• 2019

This study aimed to assess the feasibility on the wide and long 9%Ni steel plate for use in the LNG storage inner tank shell. First, 5-m-wide and 15-m-long 9%Ni steel plates were test manufactured from a steel mill and specimens taken from the plates were tested for strength, toughness, and flatness to verify their performance based on international standards and design specifications. Second, plates with a thickness of 10 mm and 25 mm, a width of 4.8~5.0 m, and a length of 15 m were test fabricated by subjecting to pretreatment, beveling, and roll bending resulting in a final width of 4.5~4.8 m and a length of 14.8m with fabrication errors identical to conventional plates. Third, welded specimens obtained via shield metal arc welding used for vertical welding of inner tank shell and submerged arc welding used for horizontal welding were also tested for strength, toughness and ductility. Fourth, verification of shell plate material and fabrication was followed by test erection using two 25-mm-thick, 4.5-m-wide and 14.8-m-long 9%Ni steel plates. No undesirable welding failure or deformation was found. Finally, parametric design using wide and long 9%Ni steel plates was carried out, and a simplified design method to determine the plate thickness along the shell height was proposed. The cost analysis based on the parametric design resulted in about 2% increase of steel weight; however, the construction cost was reduced about 6% due to large reduction in welding work.

• Steel and Composite Structures
• /
• 제32권4호
• /
• pp.549-557
• /
• 2019

The use of shear studs usually placed in the form of mechanical shear connectors makes it possible to adopt composite steel-concrete structures in various structures, and steel-concrete plate composite (SCP) is being seriously considered for the installation of storage tanks exposed to harsh environments. However, manufacturing of SCP must be based on the application of existing design guidelines which require very close arrangement of shear studs. This means that the direct application of current design guidelines usually produces very conservative results and close arrangement of shear studs precludes pouring concrete within exterior steel faceplates. In this light, an improved guideline to determine the stud spacing should be introduced, and this paper proposes an improved ratio of the stud spacing to the thickness of steel plate on the basis of numerous parametric studies to evaluate the relative influence of the stud spacing on the stability of the SCP.

• 한국공간구조학회논문집
• /
• 제22권4호
• /
• pp.49-57
• /
• 2022

In this study, based on the research results of the steel plate and steel rod dampers with rocking behavior, the moment and the drift ratio were compared and evaluated. As a test result evaluation, it was showed that the behavior of R15-200 and R15-140 was very good than other dampers. And the steel rod damper showed in-plane behavior to the loading direction, and was evaluated to prevent out-of-plane behavior that causes performance degradation.

• Steel and Composite Structures
• /
• 제10권1호
• /
• pp.87-108
• /
• 2010

A Steel Plate Shear Wall (SPSW) is a lateral load resisting system consisting of an infill plate located within a frame. When buckling occurs in the infill plate of a SPSW, a diagonal tension field is formed through the plate. The study of the tension field behavior regarding the distribution and orientation patterns of principal stresses can be useful, for instance to modify the basic strip model to predict the behavior of SPSW more accurately. This paper investigates the influence of torsional and out-of-plane flexural rigidities of boundary members (i.e. beams and columns) on the buckling coefficient as well as on the distribution and orientation patterns of principal stresses associated with the buckling modes. The linear buckling equations in the sense of von-Karman have been solved in conjunction with various boundary conditions, by using the Ritz method. Also, in this research the effects of symmetric and anti-symmetric buckling modes and complete anchoring of the tension field due to lacking of in-plane bending of the beams as well as the aspect ratio of plate on the behavior of tension field and buckling coefficient have been studied.

• 한국가스학회지
• /
• 제19권1호
• /
• pp.18-22
• /
• 2015

본 연구는 LPG 강재용기에서 상단반구와 하단반구의 코너반경이 응력강도 안전성에 미치는 영향을 FEM으로 해석한 것이다. FEM 해석결과에 의하면, 응력강도 안전성에 큰 영향을 미치는 요소는 용기의 두께보다 상단반구 및 하단반구의 코너반경이다. 그러나 강재용기의 두께는 경량화에 직결되기 때문에 간과해서는 안 되는 중요한 설계요소이다. LPG 강재용기의 강도안전성 검사에서 최고시험압력이 3.04MPa임을 감안할 때, 20kg용 LPG 강재용기의 두께는 2.3~2.6mm, 상단반구와 하단반구의 코너반경은 157mm 이상으로 최적화 설계하는 것이 바람직함을 알 수 있다.

• 열처리공학회지
• /
• 제34권4호
• /
• pp.171-178
• /
• 2021

In the present study, we comparatively investigated the microstructures of two hot-rolled stainless steel clad plates; STS 304L - low carbon steel A516-70N and STS 316L - A516-70N. The STS 304L/A516-70N clad plate (Clad_304L_Ni) had a Ni-interlayer between stainless steel and carbon steel and a 90 ㎛ thick deformation band of unrecrystallized austenite grains on the stainless steel. The STS 316L/A516-70N clad plate (Clad_316L) had no interlayer and almost fully recrystallized austenite grains. Clad_304L_Ni exhibited the thinner a decarburized layer in carbon steel and a total carburized layer in stainless steel than Clad_316L. However, a severely carburized layer in stainless steel was thicker for Clad_304L_Ni than Clad_316L. Hardness profiles near the interface of clad plates matched well with microstructures at locations where the hardness values were measured.

• Coupled systems mechanics
• /
• 제7권5호
• /
• pp.555-581
• /
• 2018

The moment-resistant steel frames are frequently used as a load-bearing structure of buildings. Global response of a moment-resistant frame structure strongly depends on connections behavior, which can significantly influence the response and load-bearing capacity of a steel frame structure. The analysis of a steel frame with included joints behavior is the main focus of this work. In particular, we analyze the behavior of two connection types through experimental tests, and we propose numerical beam model capable of representing connection behavior. The six experimental tests, under monotonic and cyclic loading, are performed for two different types of structural connections: end plate connection with an extended plate and end plate connection. The proposed damage-plasticity model of Reissner beam is able to capture both hardening and softening response under monotonic and cyclic loading. This model has 18 constitutive parameters, whose identification requires an elaborate procedure, which we illustrate in this work. We also present appropriate loading program and arrangement of measuring equipment, which is crucial for successful identification of constitutive parameters. Finally, throughout several practical examples, we illustrate that the steel structure connections are very important for correct prediction of the global steel frame structure response.

• 대한조선학회 특별논문집
• /
• 대한조선학회 2017년도 특별논문집
• /
• pp.8-13
• /
• 2017

The rolled carbon steel plate has anisotropic property in Z-direction(thickness direction). This is induced by cooling rate difference of Z-direction and sulfur which make non-metallic inclusion(MnS) at center line of thickness direction. Z-directional mechanical properties of normal steel plate are not generally specified and it is defined for Z-Quality steel only through tensile test in Z-direction. If Z-quality steel is not applied for cruciform joint, the lamella tearing will be occurred by tensile stress after welding & during operation of the structure. In this research, one equation estimating Z-directional(orthogonal to plate) stress was developed to prevent lamella tearing by welding. This equation deals with plate thickness & joint configuration(eccentricity, angle and curvature). Analyses were done by strain boundary method using sectional FE modeling and FE 3D models are also used for some cases. Designers can predict the possibility of lamella tearing by adequately applying the result and can appropriately minimize the application of Z-quality steel by revising welding design to some extent.

• Steel and Composite Structures
• /
• 제6권6호
• /
• pp.531-555
• /
• 2006

H-shaped welded steel column members are fabricated by welding together pre-cut flanges and the web. Modern fabricators are increasingly using plasma-cutting technique instead of traditional flame cutting. Different fabrication techniques result in different degrees of geometric imperfections and residual stresses, which can have considerable influence on the strength of steel columns. This paper presents the experimental investigation based temperature profiles, geometric imperfections, and built-in residual stresses in plasma cut-welded H-shaped steel column members and in similar flame cut-welded H-shaped steel columns. Temperature measurements were taken during and immediately after the cutting operations and the welding operations. The geometric imperfections were established at closely spaced grid locations on the original plates, after cutting plates into plate strips, and after welding plate strips into columns. Geometric imperfections associated with plasma cut element and members were found to be less than those of the corresponding elements and members made by flame cutting. The "Method of Section" technique was used to establish the residual stresses in the plate, plate strip, and in the welded columns. Higher residual stress values were observed in flame cut-welded columns. Models for idealized residual stress distributions for plasma cut and flame cut welded sections have been proposed.