Theories of advanced composite structures are too difficult for such field engineers and some simple methods are necessary. In this paper, Simple method of vibration analysis is presented. This method presented in this paper is studied self-weight and other loads. The result of the 2~3 times iteration is good enough for field engineering purposes. In the case of cantilevered composite materials beams with different cross section, increase of mass near the support does not significantly affect the vibration characteristics. As a calculations of the simple method of vibration analysis for cantilevered composite materials beams with different cross section, it is noted that the result of the second cycle at the point of free end (actually 5L/6 span) is only 2.2% away from the ‘exact’ solution.

1. INTRODUCTION
 2. METHOD OF ANALYSIS
  2.1 Specially Orthotropic Theory
  2.2 Simple method of vibration analysis
 3. NUMERICAL EXAMPLES
  3.1 Simple method of vibration analysis
  3.2 Influence of different cross section on naturalfrequencies
 4. CONCLUSION
 REFERENCES

• 한봉구(서울과학기술대학교 건설시스템공학과 교수) | Han Bong Koo Corresponding author
• 장재창(서울과학기술대학교 건설시스템공학과 박사과정) | Jang Jae Chang