• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 1998.10a
• /
• pp.136-143
• /
• 1998

Elastomeric bearing is used as one of the most useful way for isolation structures, because the horizontal stiffness is much lower than the vertical stiffness. The quality of Elastomeric bearing depends on the vulcanization procedure to manufacture, which produces the elasticity of the rubber from the compound of rubber and sulphur. The durability of Elastomeric bearing is affected by the deterioration due to ozone and ultra-violet attack. but the durability during the design life of bridges can be assured by the sufficient size of the bearing in spite of the deterioration in surface. In the design criteria of Elastomeric bearing, the stability of the bearings is evaluated by shear strain due to compression, lateral displacement, and rotation. The question how soft rubber can sustain heavy structure is now able to be solved by Ultimate capacity test of Laminated elastomeric Bearings, which results 1,200kg/$\textrm{cm}^2$ of the max. compressive stress and this shows what a sufficient safety factor Elastomeric bearing has!

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10a
• /
• pp.481-488
• /
• 1998

Elastomeric bearing is used as one of the most useful way for isolation structures, because the horizontal stiffness is much lower than the vertical stiffness. In the design criteria of Elastomeric bearing, the stability of the bearings is evaluated by shear strain due to compression, lateral displacement, and rotation. The question how soft rubber can sustain heavy structure is now able to be solved by Ultimate capacity test of Laminated Elastomeric Bearings, which results 1,200kg/$\textrm{cm}^2$ of the max. compressive stress and this shows what a sufficient safety factor Elastomeric bearing has !

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.6
• /
• pp.612-619
• /
• 2010

In this paper, an elastomeric bearing for a helicopter rotor hub is designed using nonlinear finite element method. The elastomeric bearing is the main component of the helicopter rotor hub that acts as a hinge to three motions(flapping, lagging and pitching) of rotor blade. The elastomeric bearing consists of rubber and metal plates. The stiffness design of the elastomeric bearing is important because elastic deformation of rubber is served to hinge. Accordingly, the elastomeric bearing is designed to satisfy the stiffness requirements for rotor hub bearing. In this study, a FE model generation algorithm is developed and stiffness characteristic of a rubber plate is analyzed for an efficient design of the spherical elastomeric bearing. It is proven that the elastomeric bearing satisfies stiffness requirements of the spherical bearing for a helicopter rotor hub.

• Structural Engineering and Mechanics
• /
• v.81 no.2
• /
• pp.117-129
• /
• 2022

This research evaluated the different types of deck to pier connections effects (one or two elastomeric bearing lines and rigid) on a concrete bridges. Three-dimensional bridge models behavior with different deck to pier connections and different distances of two bearing lines were studied under the service load. Also, the detailed connection system with two elastomeric bearing lines was modeled to evaluate the effect of changing distance between two-lines. Results indicated that the proper location of elastomeric bearings has a major impact on the transferring forces to the substructure. Double elastomeric bearing lines have a behavior between one line and rigid connections. Transferring bending moment to the substructure in two-lines is more than the corresponding value of the one line. Moreover, an increase in the distance of two-lines lead to a significant increase in the rotational stiffness of the connection, and an analytical solution was investigated for their relation. In fact, the semi-rigidity effect of this connection and its change due to the distance of bearings should be considered in the design process.

• Journal of Mechanical Science and Technology
• /
• v.18 no.1
• /
• pp.20-29
• /
• 2004

This paper proposes a new type of bearing system. In this study, a method for design of on elastomeric bearing system and its mechanical property analysis are carried. Experimental and theoretical studies of the elastomeric bearings with fiber reinforcement were proved effective new lightweight bearing system. The fibers in the bearings for isolation are assumed to be flexible in extension, in contrast to the steel plates in the conventional bearing system. Several kinds of bearing systems in the form of long strips are designed, fabricated and tested. The results suggest that it is possible to produce the economical and effective fiber-reinforced elastomeric bearing that matches the behavior of a steel-reinforced bearing. Feasibility and advantages of the proposed bearings are illustrated by the application of the analytic procedure to the structure system. Results obtained here are reported to be an efficient approach with respect to bearing system and design of bearing against shock absorbing system when compared with other conventional one.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.815-820
• /
• 2011

The railway bridge of the domestic still has been used steel base such as sperical bearing and pot bearing widely. However, the bearing of steel series is occured corrosion frequently, reduced durability and raised maintenance cost excessively due to the nature of the material. If the elastomeric bearing which is widely used in highway bridge is applied to the railway bridge, it will be able to compensate this defect a lot. In order to apply to the railway bridge used for highway bridge, is needed the control of the bridge ends deflection, lateral displacement and negative reaction. Therefore, the elastomeric bearing can be applied to the railway bridge enough, if installed negative reaction key for control of the bridge ends deflection, improved shear wedge performance for control of the lateral force, adjust the thickness of the elastomeric pad for the minimize deflection, in addition, can be economic design of sub-structures due to damping effect.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1697-1702
• /
• 2010

It has been recognized for decades that the spherical bearing which is sliding on curved surface in the intrinsic behavior is optimized for the railway bridge requiring a large slope deflection. However, the spherical bearing is easily corrosived at the PSC girder bridge which is exposed to the outside so the normal function of bridge bearing is not fulfilled fully. It is common that the corrosion is happened at the operating plate of steel bridge bearing and generally it is necessary to replace the bridge bearing after 20~25 years. Accordingly, It costs multi billion dollars for maintenance each year and the necessity of improvement become a issue. Korea Rail Network Authority(KR) suggested to apply the Elastomeric bearing instead of Spherical bearing through the task of construction site of 2006. But the normal Elastomeric bearing is optimized for the Highway bridge so it needs the special consideration to satisfy each design condition required by railway bridge. As the result of examination of Elastomeric bearing at the railway bridge construction site, the stress is decreased by effective dispersion of earthquakes and the maintenance fee is also decreased.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.37 no.4
• /
• pp.681-691
• /
• 2017

In this research, life cycle inventory database (LCI DB) was developed for elastomeric bearing employing life cycle assessment (LCA) methodology additionally the reliability improvement rate in the evaluation of the environmental load of the bridge was analyzed. As are result of impact assessment by 6 major impact categories, production of elastomeric bearing puts on environmental impact in the order of resource depletion, global warming, photochemical oxidant creation. and among a wide variety of input, steel plates contributes in most of the impact categories. As a result of applying the elastomeric bearing LCI database constructed in this study, the environmental loads increased by 0.53% on average, and the cut-off based on the cost of input materials increased by 11.36%. It is anticipated that it will be possible to improve the credibility and to provide data based on current production technology, such as estimating GHG emissions and evaluating environmental load, by constructing elastomeric bearing LCI DB.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.2 no.4
• /
• pp.53-62
• /
• 1998

Experimental studies for the laminated elastomeric bearing and the lead-rubber bearing, those are often used to improve the seismic capacity of the structures recently, are conducted to evaluate the seismic capacity of the bearings. The shear stiffness of the bearings decreases as the shear strain amplitude or the constant axial load level increases, but not sensitive to the strain rates effect. Bearings are strong for the axial compression but weak for the axial tension.

• Structural Engineering and Mechanics
• /
• v.49 no.3
• /
• pp.395-410
• /
• 2014

Fiber Reinforced Elastomeric Bearings (FREBs) are a relatively new type of laminated bearings that can be used as seismic/vibration isolators or bridge bearings. In an unbonded (U)-FREB, the bearing is placed between the top and bottom supports with no bonding or fastening provided at its contact surfaces. Under shear loads the top and bottom faces of a U-FREB roll off the contact supports and the bearing exhibits rollover deformation. As a result of rollover deformation, the horizontal response characteristics of U-FREBs are significantly different than conventional elastomeric bearings that are employed in bonded application. Current literature lacks an efficient analytical horizontal stiffness solution for this type of bearings. This paper presents two simplified analytical models for horizontal stiffness evaluation of U-FREBs. Both models assume that the resistance to shear loads is only provided by an effective region of the bearing that sustains significant shear strains. The presented models are different in the way they relate this effective region to the horizontal bearing displacements. In comparison with experimental results and finite element analyses, the analytical models that are presented in this paper are found to be sufficiently accurate to be used in the preliminary design of U-FREBs.