Damage Identification of Semi-Rigid Joints in Frame Structures Based on Additional Virtual Mass Method.

Area of Science:

• Civil Engineering
• Structural Health Monitoring
• Mechanical Vibrations

Background:

• Structural joints are critical components in civil engineering, yet their damage is often difficult to detect.
• Traditional modal analysis methods show limited sensitivity to localized joint damage in frame structures.

Purpose of the Study:

• To develop a novel method for identifying damage in semi-rigid joints of frame structures.
• To enhance the sensitivity of modal information to local joint damage using additional virtual mass.
• To accurately locate and quantify the extent of joint damage.

Main Methods:

• Modeling of semi-rigid joints and construction of virtual structure frequency response.
• Extraction of natural frequencies using the ERA (Eigenvalue Realization Algorithm) method.
• Application of additional virtual masses to increase frequency sensitivity to joint damage.
• Utilizing the Improved Orthogonal Matching Pursuit (IOMP) algorithm for enhanced accuracy.

Main Results:

• Demonstrated increased sensitivity of natural frequencies to joint damage by adding virtual masses.
• Successfully performed qualitative identification of potential joint damage.
• Achieved accurate identification of both damage location and extent.
• Validated the method's effectiveness through numerical simulations on a three-story frame structure.

Conclusions:

• The proposed virtual mass method effectively enhances the detection of semi-rigid joint damage in frame structures.
• The integration of virtual mass and advanced algorithms like IOMP significantly improves damage identification accuracy.
• This approach offers a promising tool for structural health monitoring in civil engineering applications.