• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.9
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• pp.2165-2172
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• 1995

Optimization of mesh discretization has been proposed to improve the accuracy of limit analysis solution of collapse load by using the Rigid Body Spring Model(R. B. S. M) under the plane strain condition. Moreover, the fracture behaviour of materials was investigated by employing the fracture mechanism of a spring connecting the triangular rigid body element. It has been clarified that the collapse load and the geometry of slip boundary for optimized mesh discretization were close to those of the slip line solution. Further, the wedge-shaped fracture of a cylinder under a lateral load and the central fracture of a strip in the drawing process were well simulated.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.273-279
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• 1999

In this paper the stress and strain behaivor in near homogeneous isotropic matrix of metal like steel was studied roll forming of thin steel sheet for cylindrical pipe. Analytical results reveals a body which is on the area of square thickness along and perpendicular to the width of thin steel sheet is in the state of plane strain during roll forming. As a result construction of analytical method for calculating deformation load and stably deformed length along the width of strained steel sheet was established. Also loads applied during roll forming were analyzed using two typical thin steel sheet 12.3m thick steel sheet with 42.5kg /mm2 yield strength of pipe and 5.3mm thick steel sheet with 32.5kg/mm2 yield strength of pipe. Through this analysis applicability of the analytical method for deformation load during roll forming of cylindrical thin steel pipe was evaluated with a study of necessary production technology for roll forming and design technology for roll forming machine.

• Transactions of Materials Processing
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• v.8 no.6
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• pp.554-562
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• 1999

In this paper, the stress and strain behavior in near homogeneous isotropic matrix of metal like steel was studied during roll forming of thin steel sheet for cylindrical pipe. Analytical result reveals a body which is on the area of square thickness along and perpendicular to the width of thin steel sheet is in the state of plane strain during roll forming. As a result, construction of analytical method for calculating deformation load and stably deformed length along the width of strained steel sheet was established. Also, loads applied during roll forming were analyzed using two typical thin steel sheets. 12.3mm thick steel sheet with 42.5kg/㎟ yield strength of pipe and 5.3mm thick steel sheet with 32.5kg/㎟ yield strength of pipe. Through this analysis, applicability of the analytical method for deformation load during roll forming of cylindrical thin steel pipe was evaluated with a study of necessary production technology for roll forming and design technology for roll forming machine.

• Journal of Korean Society of Steel Construction
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• v.19 no.1
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• pp.129-137
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• 2007

In this study, the elastic out-of-plane buckling load and the effective length factor of X-bracing systems were studied. Points of the intersection of diagonals were modeled as a rigid connection or a pinned connection depending on the connection method of diagonals. The boundary condition of the intersection influences the buckling load of X-bracing systems. For each boundary condition of the intersection, effective out-of-plane length factors of X-bracing systems were derived as a function of the length ratio of tension and compression diagonals $L_P$/$L_T$, the applied force ratio of tension and compression diagonals T/P, and the Euler buckling load ratio of tension and compression diagonals $P_{ET}$/$P_{EP}$. The proposed effective out-of-plane length factors of X-bracing systems were compared with the results of previous researchers and those of the finite element analysis and their properties were verified. Finally, the effects of the boundary condition of the intersection on the out-of-plane buckling load of X-bracing systems were investigated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.191-203
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• 2006

The vibration characteristics of composite stiffened laminated plates with stiffener is presented using the assumed natural strain 9-node shell element. To compare with previous research, the stiffened plates are composed of carbon-epoxy composite laminate with a symmetric stacking sequence. Also, the result of the present shell model for the stiffener made of composite material is compared with that of the beam model. In the case of torsionally weak stiffener, a local buckling occurs in the stiffener. In this case, the stiffener should be idealized by using the shell elements. The current investigation concentrates upon the vibration analysis of rectangular stiffened and unstiffened composite plates when subjected to the in-plane compression and shear loads. The in-plane compression affect the natural frequencies and mode shapes of the stiffened laminated composite plates and the increase in magnitude of the in-plane compressive load reduces the natural frequencies, which will become zero when the in-plane load is equal to the critical buckling load of the plate. The natural frequencies of composite stiffened plates with shear loads exhibit the higher values than the case of without shear loads. Also, the intersection, between the curves of frequencies against in-plane loads, interchanges the sequence of some of the mode shapes as a result of the increase in the inplane compressive load. The results are compared with those available in the literature and this result shows that the present shell model for the stiffened plate gives more accurate results. Therefore, the magnitude, direction type of the in-plane shear and compressive loads in laminated composite stiffened plates should be selected properly to control the specific frequency and mode shape. The Lanczos method is employed to solve the eigenvalue problems.

• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.580-588
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• 2010

OPB(out-of-plane bending)-induced failure of mooring chain was firstly addressed by CALM (catenary anchor leg mooring)-type offloading buoy, located approximately one mile away from the bow of the Girassol FPSO which was installed offshore area of Angola in September 2001. This study deals with verifying the load transfer mechanism between the first free chain link and connected two chain links inside the chain hawse. OPB moment to angle variation relationships are proposed by extensive parametric study where the used design variables are static friction coefficients, proof test loads, nominal tension forces, chain link diameters, chain link grades and chain link types. The stress ranges due to OPB moments are obtained using nonlinear FEAs (finite element analyses). Final stress ranges are derived considering ones from IPT (in-plane tension) forces. Also a formula for OPB fatigue assessment is briefly introduced.

• Geomechanics and Engineering
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• v.11 no.2
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• pp.235-252
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• 2016

This paper presents a new numerical solution of the ultimate lateral capacity of rectangular piles in clay. The two-dimensional plane strain finite element was employed to determine the limit load of this problem. A rectangular pile is subjected to purely lateral loading along either its major or minor axes. Complete parametric studies were performed for two dimensionless variables including: (1) the aspect ratios of rectangular piles were studied in the full range from plates to square piles loaded along either their major or minor axes; and (2) the adhesion factors between the soil-pile interface were studied in the complete range from smooth surfaces to rough surfaces. It was found that the dimensionless load factor of rectangular piles showed a highly non-linear function with the aspect ratio of piles and a slightly non-linear function with the adhesion factor at the soil-pile interface. In addition, the dimensionless load factor of rectangular piles loaded along the major axis was significantly higher than that loaded along the minor axis until it converged to the same value at square piles. The solutions of finite element analyses were verified with the finite element limit analysis for selected cases. The empirical equation of the dimensionless load factor of rectangular piles was also proposed based on the data of finite element analysis. Because of the plane strain condition of the top view section, results can be only applied to the full-flow failure mechanism around the pile for the prediction of limiting pressure at the deeper length of a very long pile with full tension interface that does not allow any separation at soil-pile interfaces.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.144-149
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• 2001

A study for the structural strength analysis on the doubler plate subjected to the axial, biaxial in-plane compression and shear load has been performed through the systematic evaluation process. In order to estimate the proper static strength of doubler plate, non-linear elasto-plastic analysis is introduced. Gap element modeling for contact effect between main plate and doubler is prepared and nonlinear analysis procedures are illustrated based on MSC/N4W . In addition, some design guides are suggested through the consideration of several important effects such as corrosion of main plate, doubler width, doubler length and doubler thickness. Finally theses results are compared with developed design formula based on the buckling strength and general trends and design guides according to the variation of design parameters are discussed.

• Journal of the Korean Wood Science and Technology
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• v.45 no.6
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• pp.728-736
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• 2017

In this study, the bending behavior of cross-laminated timber (CLT) connected by nails were investigated. Especially, the load-carrying capacity of the nail-jointed CLT under out-of-plane bending was predicted by the lateral resistance of the used nails. Three-layer nail-jointed CLT specimens and a nail connection were manufactured by 30 mm (thickness) ${\times}$ 100 mm (width) domestic species (Pinus koraiensis) laminas and Ø$3.15{\times}82mm$ nails using a nail-gun. Shear test for evaluating the nail lateral resistance and bending test for evaluating the load-carrying capacity of the nail-jointed CLT under out-of-plane bending were carried out. As a result, two lateral resistance of the used nail, the 5% fastener offset value and the maximum value, were 913 N and 1,534 N, respectively. The predicted load-carrying capacity of the nail-jointed CLT by the 5% offset nail lateral resistance was similar to the yield points on the actual load-displacement curve of the nail-jointed CLT specimens. Meanwhile, the nail-jointed CLT specimens were not failed until the tension failure of the bottom laminas occurred beyond the maximum lateral resistance of the nails. Thus, the measured maximum load carrying capacities of the nail-jointed CLT specimens, approximately 12,865 N, were higher than the predicted values, 7,986 N, by the maximum nail lateral resistance. This indicates that the predicted load-carrying capacity can be used for designing a structural unit such as floor, wall and roof able to support vertical loads in a viewpoint of predicting the actual capacities more safely.

• Earthquakes and Structures
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• v.11 no.4
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• pp.609-627
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• 2016

Results of an experimental program are presented in this paper for the influence of vertical load on the in-plane behavior of masonry infilled steel frames. Five half-scaled single-story, single-bay steel frame specimens were tested under cyclic lateral loading. The specimens included four infilled frames and one bare frame. Two similar specimens as well as the bare frame had moment-resisting steel frames, while the remaining two specimens had pinned steel frames. For each frame type, one specimen was tested under simultaneous vertical and lateral loading, whereas the other was subjected only to lateral loading. The experimental results show that the vertical load changes the cracking patterns and failure modes of the infill panels. It improves dissipated hysteresis energy and equivalent viscous damping. Global responses of specimens, including stiffness and maximum strength, do no change by vertical loading considerably. Regarding the ductility, the presence of vertical load is ignorable in the specimen with moment-resisting frame. However, it increases the ductility of the infilled pinned frame specimen, leading to an enhancement in the m-factor by at least 2.5 times. In summary, it is concluded that the influence of the vertical load on the lateral response of infilled frames can be conservatively ignored.