Gyung-Ju Kang

Design and manufacturing of fiber reinforced elastomeric isolator for seismic isolation

Abstract In this paper an experimental analysis is presented for the mechanical characteristics of multi-layer elastomeric isolation bearings where the reinforcing element—normally steel plates—are replaced by a fiber reinforcement. The fiber reinforced elastomeric isolator (FREI), in contrast to the steel reinforced elastomeric isolator (SREI) which is assumed to be rigid both in extension and flexure, is assumed to be flexible in extension, but completely lacking flexural rigidity. The FREI is designed and fabricated for evaluation of the performance on seismic isolation. Experiments are carried out to evaluate and compare the performances of fiber reinforcement with performance of steel reinforcement, and the differences in performance among different kinds of fiber reinforcements. From the experiments, the performance of the FREI is shown to be superior to that of the SREI in view of horizontal stiffness and vertical stiffness of the isolator. Therefore, it is possible to produce an FREI that matches the behavior of an SREI. Consequently, the FREI could replace the conventional SREI for seismic isolation with low-cost manufacturing and lightweight installation.

Hole and lead plug effect on fiber reinforced elastomeric isolator for seismic isolation

Abstract This paper presents an investigation of the effect of hole and lead plug in FREI (fiber reinforced elastomeric isolator) where the reinforcing element—normally steel plates—are replaced by a fiber reinforcement. The FREI, in contrast to the SREI (steel reinforced elastomeric isolator), which is assumed to be rigid both in extension and flexure, is assumed to be flexible in extension, but completely lacking flexural rigidity. In accordance with the proposed theory, the FREI is designed and fabricated for evaluation of the performance on seismic isolation. Experiments are carried out to evaluate and compare the performances of fiber reinforcement with steel reinforcement, and the hole and lead plug effect on effective stiffness and effective damping of carbon FREI. From the experiments, the performance of the FREI is superior to that of the SREI in view of horizontal stiffness and vertical stiffness of the isolator. It has been shown that hole and lead plug do not make much differences with FREI without hole and lead plug. Therefore, it is possible to produce an FREI that matches the behavior of an SREI. Consequently, the FREI without hole and lead plug could replace the conventional SREI for seismic isolation with low-cost manufacturing and lightweight installation.

Numerical analysis and design of pinion with inner helical gear by FEM

In the design of the cold forging process one of the most important tasks is the determination of the required number of processes. Preforming in incremental steps is aimed at achieving high accuracy of the forged part, high quality of the surfaces and also decreasing the die damage during the forging process. Cold forging of pinion gear with shape of outer spur gear and inner helical gear have been investigated in this study. A numerical analysis for preform design substituting a cutting process in the gear forging was developed by means of upsetting process. By using the finite element (FE) program DEFORM-3D, the analysis is carried out. Using this simulation, the preform of the pinion and helical gear forging process was designed. The suggested valuable information regarding the forging process shows a successful attempt. The suggested process is verified by experiment. Compared to the traditional computer numerical control (CNC) processing, the upsetting process can form a preform without cutting, which leads to shorter forming time and reduced material usage.

Design and Experimental Analysis of Fiber Reinforced Elastomeric Isolator

The purpose of this study is to investigate the effect of mechanical properties of the FREI using horizontal stiffness and vertical stiffness by experiments. Two kinds of FREI are designed and fabricated. The steel plates of SREI are replaced with fibers in order to reduce the cost of fabrication and installation. At first, the Nylon fiber is adopted as feasibility study of FREI. The experimental results of Nylon FREI and SREI show that the vertical stiffness of Nylon FREI is lower than SREI, and effective damping is two times higher than SREI. Carbon is adopted, by these rusults, as strong reinforcement than Nylon and full scale of carbon FREI was designed and fabricated. By the experimental test results, it is shown that the vertical stiffness of carbon FREI is three times higher than SREI, and two times higher in effective damping. As a result, the proposed FREI can replace the SREI as a seismic isolator.

Design of Elastomeric Bearing System and Analysis of it Mechanical Properties

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.