• Magazine of the Korean Society of Agricultural Engineers
• /
• v.36 no.4
• /
• pp.56-63
• /
• 1994

The nondimensional differential equations governing the buckling loads of tapered columns and its houndarv conditions are derived, in which the effects of shear deformations are included. These equations are solved numerically using a numerical integration technique and a bracketing method to obtain the buckling loads of columns. Four types of cross-sectional shape with clamped-free end constraint are used in the numerical examples. The parametric studies of shear deformation effects on the buckling loads such as cross-sectional shape factor, shear coefficient, ratio of modulus of elasticity, slenderness ratio and section ratio are reported in tables and figures.

• Journal of the Society of Naval Architects of Korea
• /
• v.54 no.3
• /
• pp.242-249
• /
• 2017

A design system for doubler reinforcement of the ship plate members subjected to in-plane shear and biaxial compressive loads was developed. This design system of doubler reinforcement on ship plate members established by design supporting system and this system was based on the buckling evaluation process of ship plate members for these in-plane loads. Each design parameters were suggested by equations as the form of influence coefficients for the doubler reinforcement subjected to the various in-plane loads including shear load. Strength of doubler plate member reinforced on the plate member could be suggested by the equivalent flat plate thickness after the consideration of corelation equations in the design system of doubler reinforcement. Level of strength recovery of ship plate members for these in-plane loads according to the local reinforcement by doubler could be suggested by use of this design system in the initial repair design stage of shipyards.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.733-736
• /
• 1999

R/C columns, one of the main structural members of reinforced concrete structures, usually sustain the axial forces of combined dead loads and live loads. When subjected to lateral loads, however, they are repeatedly subjected to bending moment, shearing forces and brittle failure such as shear failure can occur. This failure mode is not desirable and extra reinforcement is usually needed to induce a ductile failure. The design equation which is used to evaluate the maximum shear strength of a R/C column is still unsatisfactory. The objective of this study was, therefore, to evaluate the hysteretic strengthening effect and the maximum shear strength of R/C columns strengthened using carbon fibers on the seismic performance of the R/C columns under anti-symmetrical by acting moment. According to this study, it may be suggested that the shear of the strengthened R/C column were adequate to induce ductile failures.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.19 no.4
• /
• pp.67-73
• /
• 2011

For loads analysis of airplane, applicable regulation should be determined. Then, loads conditions are prepared from the regulation. Modeling for aerodynamic, mass, and structure are performed. Panel method is usually adopted for aircraft loads analysis to obtain air loads. The ARGON which is a multidisciplinary fixed wing aircraft design software co-developed by the KARI and TsAGI are used for loads analysis. The ARGON can be utilized for flutter and stress analysis as well as for flight and ground loads analysis. In this paper, flight loads analysis for wing structural design of the regional aircraft at the conceptual design phase are performed with the ARGON. FAR 25 is used for the regulation for the load analysis. Shear force, bending moment and torsion diagrams for the wing and shear force and hinge moment for the aileron are presented.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.138-141
• /
• 2006

Shear wall-frame system is one of the most, if not the most, popular system for resisting lateral loads. The core is the primary lateral load-resisting systems, the perimeter frame is designed for gravity loads, and the connection between perimeter frame and core is generally a shear connection. Specially, single plate shear connection have gained considerable popularity in recent years due to their ease of fabrication and erection. Single plate shear connection should be designed to satisfy the dual criteria of shear strength and rotational ductility. An experimental program was undertaken to evaluate seismic behavior of single plate shear connection. The main test variable is the reinforcing detail of connection. Through the experimental program, the cyclic behavior of typical and reinforcing single plate shear connection was established.

• Structural Engineering and Mechanics
• /
• v.6 no.2
• /
• pp.143-159
• /
• 1998

The objective of this present work is to estimate the failure loads, associated maximum transverse displacements, locations and the modes of failure, including the onset of delamination, of thin, square symmetric laminates under the action in-plane positive (+ve) shear load. Two progressive failure analyses, one using the Hashin criterion and the other using a Tensor polynomial criterion, are used in conjunction with finite element method. First order shear deformation theory along with geometric non-linearity in the von Karman sense have been employed. Variation of failure loads and failure characteristics with five type of lay-ups and three types of boundary conditions has been investigated in detail. It is observed that the maximum difference between failure loads predieted by various criteria depends strongly on the laminate lay-up and the flexural boundary restraint. Laminates with clamped edges are found to be more susceptible to failure due to transverse shear (ensuing from the out of plane bending) and delamination, while those with simply supported edges undergo total collapse at a load slightly higher than the fiber failure load. The investigation on negative (-ve) in-plane shear load is in progress and will be communicated as part-II of the present work.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.3
• /
• pp.130-133
• /
• 2010

A flexible three-axial tactile sensor was fabricated on Kapton polyimide film using polymer micromachining technology. Nichrome (Ni:Cr = 8:2) strain gauges were positioned on an etched membrane to detect normal and shear loads. The optimal positions of strain gauges were determined through strain distribution from finite element analysis. The sensor was evaluated by applying normal and shear loads from 0 N to 0.8 N using an evaluation system. Sensitivity of the tactile sensor to normal and shear loads was about 206.6 mV/N and 70.1 mV/N, respectively. The sensor showed good linearity, and its determination coefficient ($R^2$) was about 0.982. The developed sensor can be applied in a curved or compliant surface that requires slip detection and flexibility, such as a robotic fingertip.

• Structural Engineering and Mechanics
• /
• v.54 no.3
• /
• pp.491-500
• /
• 2015

Under seismic loading, underground station structures behave differently from above ground structures. Underground structures do not require designated energy dissipation system for seismic loads. These structures are traditionally designed with shear or racking deformation capacity to accommodate the movement of the soil caused by shear waves. The free-field shear deformation method may not be suitable for the design of shallowly buried station structures with complex structural configurations. Alternatively, a station structure can develop rocking mechanisms either as a whole rigid body or as a portion of the structure with plastic hinges. With a rocking mechanism, station structures can be tilted to accommodate lateral shear deformation from the soil. If required, plastic hinges can be implemented to develop rocking mechanism. Generally, rocking structures do not expect significant seismic loads from surrounding soils, although the mechanism may result in significant internal forces and localized soil bearing pressures. This method may produce a reliable and robust design of station structures.

• Journal of the Korean GEO-environmental Society
• /
• v.23 no.12
• /
• pp.25-31
• /
• 2022

Unlike structures installed on land, the structures installed on the offshore ground must consider long-term cyclic loads such as wave loads, wind loads and tidal loads at sea. Therefore, it is important to analyze the behavior of the ground subjected to long-term cyclic loads in order to design a structure installed on the ocean ground. In this paper, cyclic simple shear tests were performed to analyze the ground behavior for long-term cyclic loads according to the confining pressure, and a three-dimensional design failure curve was prepared that can easily check the failure characteristics according to the confining pressure. As a result of the analysis, it was confirmed that the position of the design failure curve is different depending on the confining pressure even under the same conditions of the cyclic shear stress ratio and the average shear stress ratio, and the number of cyclic loads reaching failure is affected by the confining pressure. From the created 3-D design failure curve under different confining pressure, the tendency and approximate value of the design failure curve according to the confining pressure can be estimated.

• Structural Engineering and Mechanics
• /
• v.27 no.6
• /
• pp.741-771
• /
• 2007

Tests were conducted on two partially pre-stressed concrete solid beams subjected to combined loading of bending, shear and torsion. The beams were designed using the Direct Design Method which is based on the Lower Bound Theorem of the Theory of Plasticity. Both beams were of $300{\times}300mm$ cross-section and 3.8 m length. The two main variables studied were the ratio of the maximum shear stress due to the twisting moment, to the shear stress arising from the shear force, which was varied between 0.69 and 3.04, and the ratio of the maximum twisting moment to the maximum bending moment which was varied between 0.26 and 1.19. The required reinforcement from the Direct Design Method was compared with requirements from the ACI and the BSI codes. It was found that, in the case of bending dominance, the required longitudinal reinforcements from all methods were close to each other while the BSI required much larger transverse reinforcement. In the case of torsion dominance, the BSI method required much larger longitudinal and transverse reinforcement than the both the ACI and the DDM methods. The difference in the transverse reinforcement is more pronounce. Experimental investigation showed good agreement between design and experimental failure loads of the beams designed using the Direct Design Method. Both beams failed within an acceptable range of the design loads and underwent ductile behaviour up to failure. The results indicate that the Direct Design Method can be successfully used to design partially prestressed concrete solid beams which cater for the combined effect of bending, shear and torsion loads.