Axial Force Identification of Short Beam Members with Unknown Boundary Conditions Incorporating Rotational Inertia.

Area of Science:

• Structural Engineering
• Mechanical Engineering
• Vibrational Analysis

Background:

• Accurate axial force identification in beams with unknown boundary conditions is crucial for structural safety.
• Existing methods often rely on Euler-Bernoulli beam theory, neglecting rotational inertia, which limits accuracy for short members.

Purpose of the Study:

• To develop a novel axial force identification method that incorporates rotational inertia effects.
• To enhance the accuracy of axial force identification for beam structures, particularly short members.

Main Methods:

• Derived a free-vibration governing equation for axially loaded beams using the Reissner energy approach, accounting for rotational inertia.
• Developed an identification method utilizing measured natural frequencies and mode shapes based on the new dynamic formulation.
• Validated the method through numerical simulations and experimental investigations.

Main Results:

• The proposed method, including rotational inertia, shows improved axial force identification accuracy compared to conventional methods.
• Accuracy enhancements are most significant for short beam members and higher-order vibrational modes.
• Experimental validation confirmed the method's effectiveness, achieving up to a 7.69% reduction in identification error.

Conclusions:

• The developed method effectively identifies axial forces in beams with unknown boundary conditions.
• Accounting for rotational inertia is essential for accurate axial force identification, especially in short beam members.
• The study provides a more robust approach for structural health monitoring and assessment.