Mr. Youjin Kim Profile

Youjin Kim

at KAIST

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 9 May 2024 Presentation + Paper

Optimizing the structural shape of magneto-rheological elastomers for enhanced performance

Youjin Kim, Seohyun Min, Chanwoo Lee, Hyung-Jo Jung

Proceedings Volume 12946, 129461V (2024) https://doi.org/10.1117/12.3010214

KEYWORDS: Magnetism, Materials properties, 3D printing, Vibration, Design, Smart materials, Viscoelasticity

Read Abstract +

Smart materials that can change their stiffness and damping properties in response to external changes are being utilized in a variety of applications, including structural control and vibration dampening. Magnetorheological elastomers (MREs), a type of smart material, exhibit changes in stiffness or damping performance when exposed to an external magnetic field. This unique property of MR materials is an advantage and can be utilized in damping system. In order to utilize MR materials in vibration dampening devices, it is important to maximize the dynamic properties of the device. To enhance the change in dynamic properties when a magnetic field is applied, topology optimization was used to find the design that maximizes the change in natural frequency, which is one of the important parameters indicating dynamic properties. The material properties of MR were reproduced using data from existing literature, and analysis was performed. The volume fraction was changed in order to optimize the topology. It was observed that the natural frequency increased by over 40% compared to the original when the volume fraction was set to 50%. The volume fraction with the largest difference was identified. This study can serve as a fundamental research for producing devices that reduce vibration.

Proceedings Article | 22 March 2021 Presentation + Paper

Energy harvesting and damping force of the vibration through the regenerative hybrid electrodynamic damper

Youjin Kim, Seungkyung Kye, Hyung-Jo Jung

Proceedings Volume 11588, 115881B (2021) https://doi.org/10.1117/12.2583315

KEYWORDS: Energy harvesting, Signal attenuation, Electrodynamics, Resistance, Electromagnetism, Civil engineering

Read Abstract +

Cable vibration and monitoring the cable maintenance are inevitable parts of cable bridges. To integrate both problems, the electromagnetic (EM) devices are proposed to self-power damper and studied in various ways. The conventional EM devices have a lack of damping performance that additional damping is needed to mitigate the cable vibration. Therefore, the regenerative hybrid electrodynamic damper (RHED) is developed to increase the damping performance which can mitigate the cable vibration properly while electrical energy is generated. In this study, experiments for mechanical damping of RHED and vibration induced electrical energy are conducted to investigate the RHED configuration. The applied damper has various characteristics that can be used in civil engineering such as high induced voltage and variation of damping force. The damping force is varying according to external resistance and condition of excitation. The characteristics of RHED are considered to produce the energy harvesting circuit. This study increases the harvesting energy and charges the rechargeable battery through the proposed circuit. Besides, the proposed harvesting circuit perform more than 70% efficiency in certain excitation. As the result, energy harvesting and damping mechanism can be utilized simultaneously by grasping the relationship between the RHED and a circuit.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years