Theories for composite structures are too difficult for design engineers for construction. The purpose of this paper is to demonstrate to the practicing engineers, how to apply the advanced composite materials theory to the structures. In this study, the natural frequency of a laminated cantilever beam was studied. An ultrasonic testing platform was employed to resonate the beam, and its time domain signal was optically measured. The natural frequency was quantified through the fast Fourier transform of the waveform, and the result showed good agreement with a theoretical estimation from the Euler-Bernoulli beam theory. This study is expected to provide a dynamic evaluation technique for laminated cantilever beam structures.

1. 서 론
 2. 적용 이론
  2.1 Rayleigh 이론
  2.2 Euler-Bernoulli 보 이론
 3. 실험 및 결과분석
  3.1 시험시편
  3.2 실험장치 및 방법
  3.3 실험결과 및 분석
 4. 결 론
 REFERENCES

• 김윤영(동의대학교 기계자동차로봇부품공학부, Assistant Professor, Division of Mechanical, Automotive, and Robot Component Engineering, Busan, Korea) | Kim, Yun Young
• 한봉구(서울과학기술대학교 건설시스템공학과, Professor, Department of Civil Engineering, Seoul National University of Science & Technology, Seoul, Korea) | Han, Bong Koo Corresponding author