Diagnostics of Bolted Joints in Vibrating Screens Based on a Multi-Body Dynamical Model

Area of Science:

• Mechanical Engineering
• Vibration Analysis
• Condition Monitoring

Background:

• Condition-based maintenance of vibrating screens is challenging due to signal disturbances.
• Failed bolted joints in sieving decks cause significant repair time and labor costs.

Purpose of the Study:

• To develop a model-based diagnostic method for bolted joint degradation in vibrating screens.
• To improve the reliability and reduce maintenance costs of vibrating screen systems.

Main Methods:

• Modal analysis of a 2-DOF system considering screen body and upper deck interaction.
• Investigating the impact of bolted joint degradation on system dynamics.
• Verification using laboratory vibrating screen experiments and noise addition for robustness testing.

Main Results:

• The second natural mode can coincide with excitation frequencies, accelerating bolt loosening.
• Proposed bolt health indicators (natural mode frequency, damping factor, PSP distortion) effectively detect joint degradation.
• A diagram for assessing joint strength capacity and planning maintenance was developed.

Conclusions:

• The model-based approach enhances diagnostics for vibrating screen bolted joints.
• Early detection of joint degradation prevents abrupt failures and reduces maintenance costs.
• The method offers a pathway to optimize maintenance strategies and reduce energy consumption.