Structural analysis and optimization design of mechanical pendulum of differential capacitance seismometer

Area of Science:

• Geophysics and seismology
• Mechanical engineering
• Finite element analysis

Background:

• Seismometers are crucial for real-time earthquake data collection, vital for prediction and monitoring.
• Differential capacitance seismometers face challenges with high natural frequencies in their mechanical pendulums.
• Optimizing mechanical pendulum design is key to improving seismometer performance.

Purpose of the Study:

• To address the high natural frequency issue in differential capacitance seismometer mechanical pendulums.
• To enhance the performance and accuracy of seismometers through design optimization.
• To demonstrate a feasible method for reducing the natural frequency of mechanical pendulums.

Main Methods:

• Established a finite element model of the mechanical pendulum using ANSYS simulation software.
• Performed static and modal analysis on the critical cross reed structure.
• Utilized topological optimization to refine the reed's shape.
• Employed the sine calibration method for natural frequency measurement.

Main Results:

• The optimization process successfully reduced the mechanical pendulum's natural frequency.
• The natural frequency decreased by 22%, from 5.4 Hz to 4.2 Hz.
• Validated the effectiveness of the topological optimization technique.

Conclusions:

• The design optimization significantly lowered the natural frequency of the mechanical pendulum.
• The study confirms the feasibility of using finite element analysis and topological optimization for seismometer improvement.
• Optimized seismometer components can lead to more accurate earthquake monitoring and prediction.