Direct and Inverted Pendulums

Direct and Inverted Pendulums

The Direct and Inverted Pendulums are highly precise, gravity-referenced instruments designed for monitoring and measuring small angular displacements in a wide range of engineering and geotechnical applications. These pendulums are particularly effective in detecting minute movements, providing accurate measurements that are essential for structural health monitoring, geological studies, and other applications requiring precise tilt measurements.

The Pendulums systems namely Direct type and Inverted type - both consists of a robust stainless-steel structure with an integrated damping system to reduce oscillations and ensure stable readings. The Direct Pendulum is mounted with its pivot point directly above the centre of the pendulum's motion, while the Inverted Pendulum uses a more advanced design where the pivot point is below the suspended mass, offering additional stability for specific measurement conditions.

These instruments are ideal for long-term, continuous monitoring of structural and environmental conditions, ensuring early detection of potential issues in dams and high rise buildings (skyscrapers).

Their high sensitivity, combined with easy installation and minimal maintenance, makes the Direct and Inverted Pendulums an essential tool for professionals in the field of engineering, construction, and environmental monitoring.

Working Principle:

The direct pendulum consists of a steel wire anchored at the upper end of the dam, with a weight in tension suspended at the lower end, free to move in a tank filled with a damping fluid.

The inverted pendulum provides a fixed bottom datum from which the movement of the structure can be measured. It uses a wire anchored in solid ground beneath the structure, with a floating unit attached to the upper end. The floating unit is free to move in a fluid reservoir while keeping the wire upright. Inverted and direct pendulums are often installed together in the same structure, usually gravity or arch dams

Typically, the user should select bill of materials based on deployment scenario:

1. Tank: A stainless-steel tank filled with fluid to dampen oscillations, typically used in the Direct Pendulum
2. Tensioning weight: Weights made of stainless steel, is a cylindrical tank containing lead ballast with a damping unit made by 4 cross blades.
3. Turnbuckle: A device used for adjusting the position of the damping unit inside the fluid tank for precise calibration.
4. Pendulum Arm: The main component that undergoes angular displacement when the system is subjected to gravitational forces.
5. TEL310 tele pendulum: TEL – 310 is designed to take automatic readings of the coordinates of pendulum’s plumb lines. It is characterized by high accuracy and resolution, wide measuring range and the possibility of measuring many steels wire simultaneously.

Applications of Direct and Inverted Pendulums

• Structural Health Monitoring (SHM)
• Geotechnical Monitoring.
• Construction Projects
• Mining and Tunnelling
• Railway and Highway Monitoring
• Historical Building Preservation