This paper examined the dynamic instability of a shallow arch according to the response characteristics when nearing critical loads. The frequency changing feathers of the time-domain increasing the loads are analyzed using Fast Fourier Transformation (FFT), while the response signal around the critical loads are analyzed using Hilbert-Huang Transformation (HHT). This study reveals that the models with an arch shape of h = 3 or higher exhibit buckling, which is very sensitive to the asymmetric initial conditions. Also, the critical buckling load increases as the shape increases, with its feather varying depending on the asymmetric initial conditions. Decomposition results show the decrease in predominant frequency before the threshold as the load increases, and the predominant period doubles at the critical level. In the vicinity of the critical level, sections rapidly manifest the displacement increase, with the changes in Instantaneous Frequency (IF) and Instant Energy (IE) becoming apparent.

Abstract
1. 서론
2. 아치의 지배방정식
3. 비대칭 초기 조건에 관한 동적 좌굴
4. 임계경계의 순시 주파수 변화
5. 결론
References

• 손수덕(한국기술교육대학교 건축공학과) | Shon Sudeok (Dept. of Architectural Eng., Koreatech University)
• 하준홍(한국기술교육대학교 교양학부) | Ha Junhong (School of Liberal Arts, Koreatech University) 교신저자