Motion Transmissibility - Vibration Isolation and Transmissibility - Dynamics of Machinery

TL;DR

Displacement transmissibility is the ratio of maximum response displacement to input displacement in a vibrating system, with the value being highest when the frequency ratio is at square root of 2.

Transcript

hello everyone in this video we'll discuss about displacement transmissibility now what is displacement transmissibility it is the ratio of maximum response displacement with the input displacement at the input frequency that means if there is a system at which is at some pace or at some fixed foundation and if the vibration if the foundation vibra... Read More

Key Insights

• 💆 Displacement transmissibility is a measure of how much the mass of a system is displaced in response to the displacement of its base or foundation.
• 🥳 The value of displacement transmissibility is highest when the frequency ratio is at square root of 2, indicating maximum transmission of displacement.
• 🥺 Damping plays a significant role in displacement transmissibility, with higher damping leading to a decrease in transmissibility.
• ⬛ When the frequency ratio is below square root of 2, the transmitted displacement is larger than the applied displacement, while it is smaller when the frequency ratio is above square root of 2.
• 🥳 Damping has a greater effect on displacement transmissibility when the frequency ratio is below square root of 2, but its effect is minimal when the frequency ratio is above square root of 2.
• ✋ Stops are recommended in systems where the frequency ratio varies from 0 to higher values, as they are more effective than dampers in controlling displacement transmissibility.
• ❓ The equation for displacement transmissibility is similar to the equation for force transmissibility at resonance, but with opposite values due to the difference in their definitions.

Questions & Answers

Q: What is displacement transmissibility?

Displacement transmissibility is the measure of how much the mass of a system is displaced in response to the displacement of its base or foundation.

Q: How is displacement transmissibility different from force transmissibility?

Displacement transmissibility measures the ratio of maximum response displacement to input displacement, while force transmissibility measures the ratio of transmitted force to applied force.

Q: What factors affect the value of displacement transmissibility?

The value of displacement transmissibility is influenced by the frequency ratio (omega/omega_n), with the highest value occurring at a frequency ratio of square root of 2.

Q: How does damping affect displacement transmissibility?

Damping has a significant effect on displacement transmissibility, with higher damping resulting in a decrease in transmissibility. However, the effect of damping is less significant when the frequency ratio is above square root of 2.

Summary & Key Takeaways

• Displacement transmissibility is the ratio of maximum response displacement to input displacement in a vibrating system.

• It differs from force transmissibility, which is the ratio of transmitted force to applied force.

• The value of displacement transmissibility is highest when the frequency ratio is at square root of 2.