• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.10a
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• pp.356-363
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• 2000

The objectives of this study are to investigate seismic performance of spirally reinforced bridge columns and to provide test result for developing improved seismic design criteria. Quasi-static test was conducted for 12 columns of which variables were transverse reinforcement ratio and spacing, longitudinal reinforcement ratio, and axial load level. Sufficient seismic performance was observed from the test for the columns with greater confinement steel amount than the requirement of the Korean Bridge Design Specification. The columns with 0.84% of the confinement steel requirement provided adequate performance under less than 0.2 of axial load level, but showed lower ductility under 0.3 of axial load level. The current provision for the region of confinement steel distribution may be non-conservative under high axial load level, therefore a modified provision is proposed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.2
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• pp.349-357
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• 1990

Power transmission characteristics and speed ratio-torque load-axial force relationship for a metal V-belt CVT were investigated theoretically and experimentally. In the metal V-belt CVT drive, it was found that the power was transmitted by thrust force and that band tension should be greater than compression force between the metal blocks. The experimental results for the speed ratio-torque load-axial force relationship showed good agreement with those predicted using equations developed from theoretical considerations.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.70-76
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• 2007

The purpose of this study is to analyze the characteristics of a domestic developed hydraulic axial piston motor. An experimental apparatus was constructed and the output torque, the input oil pressure, the input flow rate, the speed of motor and oil temperature were measured. They were measured under both no load and load conditions. The results are as follows; 1. Motion of motor became steady state conditions after 5 seconds. 2. Output torque of motor was proportional to input oil pressure under both load and unload. 3. Speed of motor decreased with increasing load. 4. Oil temperature was almost constant. The results of this study will offer the basic data in designing and operating hydraulic axial piston motors.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2001.09a
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• pp.423-430
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• 2001

This research was conducted to investigate the seismic behavior and ductility of circular spiral reinforcement concrete bridge columns used in high strength concrete. The experimental variables consisted of transverse steel amount and spacing, different axial load levels. From the test results, sufficient displacement ductility(at least 5.5) was observed for the columus which was satisfied wi th the requirement confinement steel amount of the Korean Bridge Design Specification. In case of the columns with 50 MPa of concrete compressive strength, the columns wi th 80 % of the confinement steel amount requirement showed adequate displacement ductility(at least 6.5) under 0.2 of axial load level. And in case of the columns with 60.2 77a of concrete compressive strength, the columns with 44 \ulcorner of the confinement steel requirement provided adequate displacement ductilit under less than 0.1 of axial load level and the columns with 0.22 % provided showed comparatively high the ducti1iffy under 0.21 of axial load level.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1997.10a
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• pp.249-253
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• 1997

A numerical method for evaluating the equilibrium path of cylindrical shell subject to axial load and eccentrically axial load is presented. The effects of both material and geometric nonlinearities were also considered in the analysis. The nonlinear formulation was based on the total Lagrangian description and nonlinear equtions were solved by the Newton-Raphson method with load increment procedures. Degenerate shell elements with layered approach were employed for the analysis. The elasto-plastic deformation can be found in several examples and a large eccentricity of the axial load reduces the stress level at the time of the local buckling of the pipe considerably.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.81-84
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• 2006

The purpose of this study is to investigate the inelastic behavior of hollow reinforced concrete bridge piers under varying axial load. The role of the variable axial load is very important in the ductility, strength, stiffness, and energy dissipation. A computer program, named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), for the analysis of reinforced concrete structures was used. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The proposed numerical method for the inelastic behavior of hollow reinforced concrete bridge piers under varying axial load is verified by comparison with reliable experimental results.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.3
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• pp.9-20
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• 1990

The speed ratio-torque load-axial force characteristics of a rubber V-belt (RVB) and a metal V-belt (MVB) CVT are investigated and their performances are compared. It is found that power is transmitted by tension difference in RVB, and by thrust difference in MVB. The nondimensional equations for speed ratio-torque load-axial force of RVB are exactly same as those of MVB. However, actual characteristics of axial forces of RVB and MVB are different depending on their power transmission methods. The torque capacity of MVB is 5-6 times higher than that of RVB due to MVB's higher strength, even if the required axial force of MVB CVT control is 3-4 times higher than that of RVB.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.3
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• pp.129-135
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• 2000

Air-dynamic bearings are increasingly used in supporting small high-speed rotating bodies. This study investigates the effects of design parameters on the axial stiffness of spiral-grooved air bearings of various curvatures. Design parameters are fundamental clearance, groove depth, and bearing number. The pressure distribution at the clearance between the stator and rotor of the bearing is obtained by solving the Reynolds equation, and the supporting load and the axial linear stiffness are calculated from the pressure distribution. It is found that a larger curvature increases the axial linear stiffness more and that there exist an optimal groove depth for the linear stiffness of the air bearing. It is also found that the linear stiffness has a linear relationship with the bearing number.

• Journal of Korean Society of Steel Construction
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• v.17 no.1 s.74
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• pp.83-92
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• 2005

This paper is to evaluate the load carrying capacities of cold-formed steel columns subject to combined axial load and bending moment. A combined strength experiment is carried out using full-scale 24 specimens of lipped channel section with embossment in web. An eccentric axial load is applied in varying member-length and eccentric distance which produces an end-moment of the column. The predictions of the AISI specification and the Eurocode are compared with the experimental results, and it is shown that all of these codes are reasonable on the whole in relation to the experimental results.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.3-10
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• 1999

Earthquake resistant R/C frame structures are generally designed to prevent the columns from plastic hinging. R/C columns under higher axial load or strong earthquake showed a brittle behavior due to the deterioration of strength and stiffness degradation. An experimental study was conducted to examine the behavior and to find the relationship between amounts of lateral reinforcements and compressive strength of ten R/C column specimens subjected to reversed cyclic lateral load and higher axial load. Test results are follows : An increase in the amount of lateral reinforcement results in a significant improvement in both ductility and energy dissipation capacities of columns. R/C columns with sub-tie provide the improved ductility capacity than those with closely spaced lateral reinforcement only. While the load resisting capacity of the high strength R/C columns is higher than the normal strength concrete columns under both an identical ratio of lateral reinforcement, however the ductility capacity of high strength R/C columns is decreased considerably. Therefore, the amounts of lateral reinforcement must be designed carefully to secure the sufficient ductility and economic design of HSC columns under higher axial load.