Structural Dynamics using Sine Processing

Our friends at Dewesoft have provided this product information on Testing Structural Dynamics using Sine Processing.  For more information, contact us.

Dewesoft give you the power to integrate and synchronise the data acquisition system seamlessly with your vibration shaker COLA signal.  To allow you to perform a powerful evaluation of structural properties on unlimited channels in real-time. The Dewesoft sine processing solution is easy to set up and will get you measuring right away.

Main Features of Testing Structural Dynamics using Sine Processing

  • COMPLETE SINE PROCESSING TESTS: Directly integrates with your existing vibration shaker table and controller. Just bring in your COLA signal to your Dewesoft data acquisition system and you are ready to go.
  • REAL-TIME RESULTS: Perform real-time calculation of Peak, RMS, phase, THD on response points and obtain transfer functions between reference and response points on the entire structure simultaneously.
  • UNLIMITED NUMBER OF CHANNELS: Dewesoft’s unique architecture of data acquisition systems allows sine processing to run on an unlimited number of channels while still maintaining all of the real-time capabilities.
  • POWERFUL CALCULATIONS: Unmatched computational power enables you to run true octave analysis in parallel with sine processing and FFT’s simultaneously on all channels in real-time. Need additional maths? Simply add it from the extensive math library available out of the box in Dewesoft X software.
  • ONLINE AND OFFLINE ANIMATION: Determine the quality of test results with the animation of structure in all three directions with different projections during (and after) the measurement.
  • EASY TO SET UP: Simply connect the accelerometers and COLA signal into the data acquisition system. TEDS technology will detect and set up sensors automatically. Assign the right channels and you are ready to start measuring and seeing results immediately.
  • ADVANCED STORING OPTIONS: Define automatic storing or desired trigger conditions and make sure you measure and store right on the absolute first time you run the sweep. Structures under investigation are often very expensive prototypes.  So Dewesoft makes sure you get it right the first time.
  • DIFFERENT MODES OF FREQUENCY DETECTION: Dewesoft sine processing solution takes your measurement to the highest possible level. Besides the widely used zero-crossing method of frequency detection, Dewesoft support Hilbert transform.  Enabling superior reading of frequency which results in smoother, more continuous data.
  • DEWESOFT QUALITY AND FLEXIBILITY: Simply add additional parameters to the same measurement system and expand your measurement chain in seconds. Add video inputs to have additional information during a test or monitor environmental conditions and any other quantities simultaneously, using the same DAQ system and software interface.
  • EASY DATA EXPORT AND REPORTING: Dewesoft X software offers built-in data export into several standard formats such as UNV or Excel and offers easy reporting creation functionality.
  • FREE SOFTWARE UPDATES AND TECHNICAL SUPPORT FOREVER: Dewesoft’s zero cost software policy and always free technical support make their sine processing solution future proof for you. New features and improvements will be added and all future updates are free forever.

 

Real-time Sine Processing Analysis Introduction

Sine Processing on Structural Products

Sine reduction (also known as sine processing) is a method of performing structural tests on large structures. The method can identify and analyse natural frequencies by exciting them with a sweep of single frequencies.

Vibration signals from accelerometers and force sensors mounted on the structure.  Are measured together with sweep frequency and are being tracked, recorded and analysed by the data acquisition system in real-time. As desired output, sine processing returns the structural resonance frequencies, amplitudes, phase, THD (total harmonic distortion) of response and also transfer functions between excitation and response points.

The COLA signal from the vibration shaker controller is used as the frequency reference for the signal analysis.

What is COLA signal?

The COLA signal (Constant Output Level Amplitude) is a constant voltage sine wave which frequency tracks the Drive signal frequency during the Sine Control test. It is the same frequency as the excitation frequency.

Dewesoft sine processing solution is the most powerful structural analysis tool which supports the evaluation of responses and transfer functions on an unlimited number of channels, all in real-time.

Sine Processing Functionality

Sine vibration testing applies a single frequency to a test item and selectively excites resonant structures within the device. In a swept sine test a vibration sine tone is ramped up and down through a range of frequencies and for a specified rate and duration.

Dewesoft’s system provides the real-time calculation and functions of the excitation frequency:

  • Detection of amplitude, frequency, and phase of the vibration reference
  • Extraction of harmonic components (Peak and RMS) of all measured signals
  • Extraction of the overall broadband signal (Peak and RMS) level of all measured signals
  • Calculation of transfer function (FRF, coherence, etc.) and the total harmonic distortion (THD) between the reference signal and any point measured on DUT.
  • Calculation of the fundamental and its harmonics

 

Flexible and Powerful Data Acquisition System

Sine reduction tests frequently require a large number of input channels. The unique architecture of their SIRIUS data acquisition systems allows them to perform the test on unlimited input channels. Even more, the data acquisition can always be extended to add additional channels, if your tests require that at any time. With no additional software licensing costs.

Many configuration possibilities:

  • 8- or 16-channel IEPE slices which can be stacked and daisy-chained together to form a large channel system
  • 32-, 64- or 128-channel single box IEPE systems which can also additionally be daisy-chained to form large systems with virtually unlimited channel count.

 

The Best Signal Amplifiers with 160 dB Dynamic Range

SIRIUS data acquisition systems offer the world’s best signal amplifiers for vibration sensors (IEPE, MEMS, Charge).

DualCoreADC® Technology – Dual 24-bit AD Converters

Amplifiers offer a high dynamic range up to 160 dB and signal to noise ratio of more than 130 dB. This is 20 times better than 24-bit systems and 20 times less noise.

The DualCoreADC technology solves often faced problems with signal measurement – input overload, noise, and artificial frequencies in the signal caused by aliasing. The input signal can be higher than expected (out-of-range) and therefore clipped by the ADC. This will result in an incorrect measurement and you will have to repeat the test all over again.

DualCoreADC technology prevents these problems. Each channel amplifier has two AD converters that always measure the high and low gain of the input signal. This results in the full possible measuring range of the sensor and prevents the signal from being clipped.

Galvanic Isolation

The data acquisition system includes high galvanic channel-to-channel and channel-to-ground isolation (±1000 V). It even includes an isolated sensor excitation.

With such isolation, Dewesoft have no problem measuring high voltage potentials and no problem with common-mode voltages. They work with measurements like vibrations, temperatures, or any other measurement where non-isolated sensors are placed next to the high voltage potential against the DAQ system ground. In such cases, a non-isolated DAQ system would burn or at least give faulty wrong results. With SIRIUS it is just one thing less to worry about.

Digital isolation has another big advantage – preserving the frequency bandwidth of the amplifiers. SIRIUS provides “worry-free” measurements, less noise, no ground loops, and the best possible signal quality.

TEDS Sensor Technology

Dewesift data acquisition systems support TEDS sensor technology for automatic sensor detection and setup. Simply connect the sensor to an input channel on our data acquisition system and the sensor will be automatically detected and set up immediately.

Both reading and writing to TEDS are supported directly in the Dewesoft X software. An extensive sensor database and editor are available which gives you a simple way to build your sensor database for future use.

Dewesoft’s data acquisition systems are compatible with any 3rd party vibration sensors including IEPE, charge and MEMS accelerometers. In other words you can always use your existing sensor inventory.

From Test to the Printed Results

Sine Processing has detailed reports

Not only does Dewesoft’s sine processing solution offers advanced analysis features, but it also offers extensive data reporting functionalities.

PDF Report Generation

Dewesoft X software includes extensive PDF data reporting and printing capabilities. When data is analysed you can generate PDF reports of your data and visual displays. Advanced reports are possible with the creation of custom templates.

Video or Image Export

The visual screens of your tests can be exported into images or video files for use in PowerPoint or other presentations.

Data Export

Dewesoft X software always stores measured raw data for later analysis and can also be exported into various standard data formats. Formats like UNV, Excel, Matlab, Flexpro, Diadem, Wav and many others are supported out of the box.

Sine Processing Applications and Case Study

Sine Processing Applications - Testing of Rocket Cone

Sine reduction and processing tests enable the detection, identification, and analysis of the tested products’ ability to function in a vibration environment, fatigue life, resonant frequencies or even squeak and rattle sound output (NVH).

The test validates and qualifies product designs. Also to establish operational limits in a range of industries:

  • Aerospace: e.g. launch system providers or satellite manufacturers.
  • Automotive: e.g. engine mounted components.
  • Defence, ground transport, and any manufacturer of larger structures that have limited room for failure and must perform perfectly on deployment.

 

A typical application that uses the sine processing test method is for Satellite qualification testing. Additionally, you can check the case study “Structural Testing of Rocket Cone”

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