NATURAL FREQUENCY OF DAMAGED FRAME STRUCTURES

The concept of damage assessment of existing structures is introduced. Damage of the structures is modelled as cracks in the structure. All of the cracks are replaced by a simulated rotational spring. Relationships between natural frequency and the cracked structures with different crack conditions are found. An equation of motion of the cracked cantilever beam is derived by Lagrange's equation. Natural frequency is then calculated by using Jacobi's method. An alternative equation of motion of the cracked cantilever beam is found by the finite element technique by assuming some proper shape functions. The two results are compared to obtain the spring constant of the simulated rotational spring which is inserted at the cracked locations. The stiffness matrix and mass matrix for the cracked element can also be calculated and the natural frequencies of any cracked plane frame structures are obtained accordingly.

• Corporate Authors:

  National Science Council, Republic of China

  2 Canton Street
  Taipei, Taiwan 107,   China 
• Authors:
  • Hsu, D S
• Conference:
  • Proceedings of the National Science Council, ROC
• Publication Date: 1986-10

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 460-467
• Serial:
  • Volume: 10
  • Issue Number: 4

Subject/Index Terms

• TRT Terms: Beams; Cantilevers; Finite element method; Framed structures; Loss and damage; Mathematical models; Natural frequency
• Uncontrolled Terms: Models
• Subject Areas: Bridges and other structures; Design; Highways; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00472603
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 31 1987 12:00AM