Frf files

In this case, the only you can do is to ask for assistance of a professional staff. If you want to associate a file with a new program e. FRF you have two ways to do it. The first and the easiest one is to right-click on the selected FRF file. From the drop-down menu select "Choose default program" , then click "Browse" and find the desired program.

The whole operation must be confirmed by clicking OK. The second and more difficult to do is associate the FRF file extension to the corresponding software in the Windows Registry. Many files contain only simple text data.

It is possible that while opening unknown files e. FRF with a simple text editor like Windows Notepad will allow us to see some of the data encoded in the file. This method allows you to preview the contents of many files, but probably not in such a structure as a program dedicated to support them. Home page. When the amplitude of the FRF is very low, for example at an anti-resonance, the coherence will have a value closer to 0. This is because the signals are so low, their repeatability is made inconsistent by the noise floor of the instrumentation.

When the coherence is closer to 0 than 1 at a resonant frequency, or across the entire frequency range, this indicates a problem with the measurement. Note that if only one measurement is performed, the coherence will be a value of 1!

This is because at least two FRF measurements need to be take and compared to start to calculate a meaningful coherence function.

When measuring a Frequency Response Function on a structure by inputting a 30 Hz forcing frequency. Using three different force levels, the following happens:. Why the variation between measurements? Unlike generating a FRF from a Finite Element Model, measuring a FRF may not return the same value every time a measurement is taken: structures are not completely linear and there can be small amounts of instrumentation noise in the measurement.

When trying to characterize a structure the following table of data was gathered over 5 individual FRF measurements at three different frequencies:.

The following is a simplified example for learning purposes. In a single FRF measurement, when looking at 3 different frequencies, the following may be observed over 5 individual measurements as shown in Table 1.

Table 1: FRF data at three different frequencies from five different measurements. These X and Y pairs are plotted, a line is fit to the data. The estimators affect how the data is fit and how much each data point is adjusted to create the best fit line. The most commonly used estimator is the H1-estimator Figure 9.

It assumes that there is no noise on the input and consequently that all the X measurements the input are accurate. All noise N is assumed to be on the output Y. This estimator tends to give an underestimate of the FRF if there is noise on the input.

H1 estimates the anti-resonances better than the resonances. Best results are obtained with this estimator when the inputs are uncorrelated. Alternatively, the H2 estimator Figure 11 can be used.

This assumes that there is no noise on the output and consequently that all the Y measurements are accurate. Noise M is assumed to be only on input X. This estimator tends to give an overestimate of the FRF if there is noise on the output. This estimator estimates the resonances better than the anti-resonances. Notice the corrections are bigger for the Hz anti-resonance frequency than for the Hz resonance frequency as shown in Figure The Hv estimator provides the best overall estimate of the frequency function.

It approximates to the H2 estimator at the resonances and the H1 estimator at the anti-resonances. It does however require more computational time than the other two, which is not an issue for today's computers. Frequency Response Functions FRFs are used to measure and characterize the dynamic behavior of a structure. When creating an average FRF, coherence functions can give indications of FRF quality, while estimation methods are used to account for noise on the measurements.

Feel free to email peter. Kevin Grenier Siemens Employee. FRF's can be used in Modal Analysis. Crosspowers or time histories to calculate Crosspowers from can be used in Operational Modal Analysis. For Excel you need a data header and you can a Copy similar data to excel to get the required headers or b ask your local support office to provide some example Excel files. In rev 17 and earlier we can import these file types. Some require extra licenses and add-ins need to be turned ON. In rev 18 and later, you don't need to turn on extra add-ins and extra licenses are not needed.

Can I Enter the processed data directly to calculate modal parameters? Detailed description. Add comment. Font and typeface file type. The frf file extension is associated with a font-conversion utility called FontMonger, developed by Ares Software Corporation. The program was created in early 90s and it is likely that it is no longer available or supported. This frf file type entry was marked as obsolete and no longer supported file format.

This type of file is no longer actively used and is most likely obsolete. This is typically the case for system files in old operating systems, file types from long discontinued software, or previous versions of certain file types like documents, projects etc. This file type is not meant to be opened directly, there is no software that could open and work with it directly, or there is no information available in public sources about opening this file type.

This is usually the case of some internal data files, caches, temporary files etc. As far as we know, this.