Research on the dynamic hammering method for identifying weak parts in cantilever structures

Area of Science:

• Mechanical Engineering
• Structural Analysis
• Vibration Analysis

Background:

• Improving structural stiffness is critical for machine tool performance.
• Identifying stiffness vulnerabilities is a key challenge in machine tool design.

Purpose of the Study:

• To propose and validate the Flexibility Matrix Diagonal element method for identifying stiffness weaknesses in cantilever structures.
• To develop a novel method for quantifying weakness levels and measuring accuracy under noisy conditions.

Main Methods:

• Hammer testing to obtain dynamic characteristics.
• Finite element simulations to model stiffness weakening scenarios.
• Singular value decomposition to establish the flexibility matrix from experimental data.

Main Results:

• The Flexibility Matrix Diagonal element method effectively identifies single and multiple stiffness weaknesses.
• The proposed quantification method accurately assesses weakness levels under noise.
• Experimental validation on a cantilever beam with elastic support confirmed the method's efficacy.

Conclusions:

• The Flexibility Matrix Diagonal element method is a valid and practical approach for identifying structural stiffness vulnerabilities.
• This method demonstrates superior accuracy compared to the Flexibility Difference Method, especially under noisy conditions.
• The study highlights the method's significant practical engineering value for machine tool optimization.