This study investigates the dynamic characteristics of telescopic booms for special-purpose vehicles fabricated with giga-grade ultra-high strength steel (UHSS) plates that have been increasingly adopted in industrial applications. In thin-walled structures such as telescopic booms, dynamic properties – particularly natural frequencies – are critical factors directly related to structural safety. Accordingly, the dynamic characteristics were experimentally measured and analyzed for identically designed booms fabricated using either imported giga-grade steel (Strenx 960) or domestic giga-grade steel (ATOS 980), both of which are widely available in the domestic market. The natural frequencies were identified based on frequency response functions (FRFs), and the corresponding mode shapes were obtained through experimental modal analysis. The results show that the nominal yield and tensile strengths provided by the manufacturers and the measured natural frequencies and mode shapes exhibit highly similar characteristics. These experimental findings confirm that the domestic UHSS exhibits a level of dynamic performance comparable to that of the imported steel of the same grade. Consequently, the results support the feasibility of applying domestic giga-grade UHSS to telescopic boom structures and highlight its potential contribution to material localization and enhanced design competitiveness in the domestic special-purpose vehicle industry.

Abstract
1. 서 론
2. 측정 대상 및 방법
    2.1 굴절식 고소작업차
    2.2 측정 대상 단품 붐
    2.3 측정 방법
3. 측정 결과 및 분석
    3.1 고유진동수 측정 결과
    3.2 고유모드 형상 비교
    3.3 결과 분석 및 고찰
4. 결 론
후 기
References

• 이명군(Vice President, K-Top Co., Ltd.) | Myung Kun Lee
• 장일도(Assistants Professor, Dept. of Mechanical Engineering, Wonkwang University) | Il Do Chang Corresponding author