Modal Space - In Our Own Little World

Is it really necessary to reject a double impact?

Are they really a problem?

Let's talk about this.

I know that many people will say that a double impact is totally unacceptable. It is not the optimum condition for collecting impact data for a modal test. However, under certain circumstances, it may be reasonable to accept a measurement that has resulted from a double impact. Let's discuss this problem that may arise when a double impact occurs and explain how to determine if the measurement is acceptable or not.

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Crystal Instruments Sponsors 2019 SAE Noise and Vibration Conference

The Society of Automotive Engineers (SAE) held the 2019 Noise and Vibration Conference in Grand Rapids Michigan this year.  The conference, which is a biennial event, took place from June 10th to the 13th and drew roughly 1,000 engineers focused on NVH (Noise, Vibration and Harshness) and sound quality measurements. Crystal Instruments was proud to take part in sponsoring the conference this year.

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Automatically Run Pre-Defined Vibration Tests Using Digital Inputs

Combined vibration testing is gaining prominence due to the advancement of test equipment technology driven by the need to accomplish simultaneous testing of multiple measurement quantities.  Vibration testing combined with temperature, humidity or a combination of other quantities has enabled the creation of test environments closely resembling typical scenarios in which DUTs operate.

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Modal Space - In Our Own Little World

I ran one test with an x-excitation and can see some modes and another test with a y-excitation and see some different modes. Could I use an oblique angle instead?

Well, that's a very good question. Its one that comes up often in terms of running modal tests with a shaker excitation. Of course it is totally acceptable to run one test with a shaker at some oblique angle to the structure. But the only thing we need to be careful about is to assure that we don't select the reference point at the node of a mode.

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2019 IEST ESTECH Conference & Exposition - Las Vegas, NV

The 2019 IEST ESTECH conference was held in Las Vegas, NV from April 29 through May 2nd, 2019.  This year, Dr. James Zhuge provided a technical presentation explaining Crystal Instruments’ combined Temperature, Humidity, and Vibration (THV) Control system.  Dr. Zhuge provided the opportunity for attendees to gain first-hand knowledge regarding Crystal Instruments latest technologies offered for environmental testing systems. The Crystal Instruments THV system provides one convenient user Interface to set up schedules for temperature, humidity, vibration, and more.

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