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Natural Frequency Calculator

Calculate the natural frequency based on mass, stiffness, and number of isolators.

Natural Frequency: — Hz

Required Stiffness Calculator

Calculate the required stiffness per isolator based on target frequency and mass.

Stiffness per Isolator: —
Total System Stiffness: —

Mass Converter

Convert mass/weight values between different units.

Result: —

Stiffness Converter

Convert stiffness values between different units.

Result: —

Length Converter

Convert length values between different units.

Result: —

Hz ↔ RPM Converter

Convert between Hertz and Revolutions Per Minute.

Enter a value in either field and click Convert. The other field will be calculated.

Result: —
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Use this calculator to estimate natural frequency, required stiffness, and unit conversions for your isolation system. These calculations are based on standard vibration theory and are intended to help you quickly evaluate isolator performance for your application.

Our engineers are available to review your results, confirm sizing, and help you select the most appropriate isolator. Reach out now for free expert support.

How do isolators work? 

Shock and vibration isolators act as flexible connections that absorb and reduce the transmission of mechanical energy into a system. In essence, an isolator functions like a mechanical low-pass filter—it allows low-frequency motion to pass while blocking higher-frequency vibration.

Isolation begins to occur when the excitation frequency exceeds approximately √2 × the system’s natural frequency (fₙ). This natural frequency depends on two key parameters:

  • Isolator stiffness (K)
  • Supported mass (m)

Understanding a system’s natural frequency is essential for predicting resonance and determining the point at which effective isolation begins.

Selecting the appropriate isolator for a system requires careful consideration of many factors, including input conditions, operating environment, system stability, nonlinearity, and overall performance requirements. Among these, natural frequency is one of the most critical parameters, as it has a direct and significant impact on isolation effectiveness and system behavior.

The Natural Frequency Calculator enables users to quickly estimate a system’s natural frequency by entering the isolator stiffness (K), the number of isolators, and the total system mass. For systems using multiple isolators with differing stiffness values, an equivalent total stiffness may be used, with the number of isolators set to one.

The natural frequency is calculated using the following equation:  

f=12Ï€KM

where:

  • f is the system natural frequency (Hz)
  • K is the total effective system stiffness
  • M is the total system mass

When applying this equation, it is essential to ensure all units are consistent and properly converted to obtain accurate results.

 

When sizing isolators for an application, the target natural frequency is first established based on several key factors, including the input excitation frequency, the payload’s resonant frequency, and the required level of isolation. Selecting an appropriate target natural frequency is critical, as it has a direct impact on overall system performance.

Once the target natural frequency is defined, the next step is to determine the isolator stiffness needed to achieve that frequency.

The Stiffness Calculator enables users to quickly calculate both the required isolator stiffness and the total effective system stiffness based on the sprung mass.

The total system stiffness is calculated using the following equation:

K=M(f*2Ï€)2

Similarly to all calculations, it is essential that all units are correct and carefully considered.

 

Frequency describes the rate at which a repeating event occurs and is commonly used to characterize waves (such as sound, light, and radio) and mechanical vibrations, indicating how fast a system oscillates.

Revolutions per Minute (RPM) describes the rotational speed of machinery and is most often applied to equipment with rotating components, such as engines, pumps, motors, and fans.

When selecting isolators for rotating equipment, it is often useful to convert rotational speed (RPM) into frequency. This information helps establish a target natural frequency and supports the proper design of an effective isolation system.

The RPM and Frequency conversion calculator allows users to quickly convert between RPM and frequency using the following equations:

f=RPM60

RPM=f*60

Selecting the right isolator isn’t always straightforward. Our team offers free engineering support to help guide you to the right solution. Contact us today to speak with an expert.

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