{"id":3516,"date":"2026-10-21T09:22:34","date_gmt":"2026-10-21T01:22:34","guid":{"rendered":"http:\/\/www.custombrassandbronze.com\/blog\/?p=3516"},"modified":"2026-10-21T09:22:34","modified_gmt":"2026-10-21T01:22:34","slug":"how-to-ensure-the-synchronization-of-multiple-vibration-exciters-4a89-a40173","status":"publish","type":"post","link":"http:\/\/www.custombrassandbronze.com\/blog\/2026\/10\/21\/how-to-ensure-the-synchronization-of-multiple-vibration-exciters-4a89-a40173\/","title":{"rendered":"How to ensure the synchronization of multiple vibration exciters?"},"content":{"rendered":"

If you\u2019ve ever been involved in large-scale vibration testing\u2014think seismic simulation for aerospace components, fatigue testing for heavy industrial machinery, or modal analysis for bridge prototypes\u2014you know that a single vibration exciter can only do so much. To replicate real-world forces accurately, you need multiple exciters working in perfect sync. But here\u2019s the thing: getting several shakers to move in unison, at the right frequency, amplitude, and phase, is not just a technical challenge\u2014it\u2019s the difference between a reliable test that delivers actionable data and a waste of time, money, and materials. As someone who\u2019s spent over a decade as a vibration exciter supplier, working with labs, manufacturers, and test engineers across 17 countries, I\u2019ve seen firsthand what goes wrong when synchronization breaks: test specimens fail prematurely, data is invalidated, and even equipment gets damaged. Today, I want to break down exactly how we (as a supplier, and as test teams) can ensure multiple vibration exciters stay in sync, no matter the test requirements. vibration exciter<\/a><\/p>\n

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Let\u2019s start with why synchronization matters. At its core, synchronization means each exciter produces a vibration signal with identical frequency, matching amplitude, and a fixed phase relationship relative to one another. For small setups\u2014say two exciters testing a small automotive subframe\u2014misalignment might show up as a slightly wobbly reading. But for large structures: a 10-exciter array testing a full airplane fuselage, for example, even a 1-degree phase shift across one exciter can create a \u201cbeat frequency\u201d that amplifies vibrations in unexpected spots, leading to test results that don\u2019t match real flight conditions. I remember a client in Germany a few years back who was testing a wind turbine tower with four exciters. They skipped proper sync setup, and during a 2-hour fatigue test, a node point on the tower developed a stress crack that wasn\u2019t present in finite element analysis (FEA) models. When they brought us in to troubleshoot, we found one exciter was 12 degrees out of phase with the others\u2014enough to create a secondary vibration that the FEA didn\u2019t account for, because the software assumed perfect synchronization. That\u2019s the kind of mistake that costs companies months of delays and hundreds of thousands of euros. So this isn\u2019t just a technical detail; it\u2019s make-or-break for test validity.<\/p>\n

First on the list: invest in a dedicated master control system, not a generic signal generator. I\u2019ve seen teams try to sync multiple exciters using off-the-shelf function generators or even basic audio interfaces, and it never works for long. Generic generators create a single signal, but they can\u2019t compensate for the inherent delays or drift in each exciter\u2019s hardware. Modern vibration control systems\u2014like the ones we design and supply with our high-force shakers\u2014use a digital signal processing (DSP) core that locks all exciters to a single 10 MHz reference clock. Wait, why 10 MHz? Because that\u2019s a frequency that\u2019s high enough to capture even the fastest vibration signals (most tests run between 1 Hz and 20 kHz, so 10 MHz is 500x the maximum frequency) but low enough to avoid introducing jitter. Jitter is tiny variations in the timing of each cycle\u2014think of a clock that\u2019s off by a nanosecond here and there. At 20 kHz, a 1-nanosecond jitter causes a phase error of 0.007 degrees, which is negligible, but if your reference clock is only 1 MHz, that jumps to 0.07 degrees\u2014still small, but enough to accumulate across 10+ exciters over a 10-hour test.<\/p>\n

Our control systems also use a technique called \u201cphase-locked loop (PLL) cascading.\u201d Here\u2019s how that works: the master control sends a reference signal to each exciter\u2019s local driver, and each driver locks to that signal using a PLL. The key is that we calibrate the PLL in each exciter during manufacturing to have less than 0.1 degrees of inherent phase error at full force. That means when the master sends a signal, each exciter adjusts its own internal timing to match the reference, so even minor differences in the exciter\u2019s armature mass or coil resistance don\u2019t throw it off. I always advise clients to avoid daisy-chaining reference signals between exciters, by the way\u2014each connection adds a tiny amount of signal delay, and if one cable is longer than another (even by a few feet), that creates a phase shift. All our exciters are designed to accept a wired or wireless reference input, but we strongly prefer hardwired for critical tests\u2014wireless can introduce latency if the network is congested, which is common in large test facilities with dozens of pieces of equipment running at once.<\/p>\n

Next: pre-test calibration and phase verification. Even with a top-tier control system, you can\u2019t just plug in exciters and start a test. I recommend a full sync check before every test sequence, especially if you\u2019re using the setup for different specimens or changing test frequencies. Here\u2019s the step-by-step process we train our clients on during our on-site installation training: first, mount all exciters to a rigid test base (we always advise a steel or concrete base that\u2019s at least 10x the total weight of all exciters to avoid base vibration contamination). Then, attach a small accelerometer to each exciter\u2019s armature\u2014not the test specimen, not the base\u2014because that\u2019s where the actual output vibration is. The accelerometer sends data back to the master control, which calculates the phase difference between each exciter relative to the master. We set our control system to automatically adjust the phase of each exciter in 0.01-degree increments until all are within \u00b10.05 degrees of the master. That might sound overly precise, but for a test running at 100 Hz, a 0.05-degree phase shift is less than 1 microsecond\u2014way below the threshold that would affect test data.<\/p>\n

I once worked with a client in Canada who was testing a heavy-duty mining truck frame with eight exciters. They skipped this pre-test calibration because they were \u201cshort on time\u201d and had to meet a deadline. Halfway through the 72-hour fatigue test, the frame\u2019s rear crossmember failed catastrophically, sending shrapnel that damaged three exciters (costing $120,000 in repairs) and took the test offline for two weeks. When we analyzed the phase data from their control system, we found the phase difference between the leading four and trailing four exciters had drifted to 1.2 degrees over the first 12 hours, and by 36 hours, it was at 4.7 degrees. That drift came from two things: the exciters\u2019 coil temperature increasing as they ran (higher temperatures change the coil\u2019s inductance, which affects the exciter\u2019s response time) and the power supply voltage dropping slightly due to the test facility\u2019s grid load as other equipment turned on. Pre-test calibration also includes setting a \u201cphase drift alarm\u201d in the control system\u2014our systems alert the test engineer immediately if any exciter\u2019s phase drifts more than 0.5 degrees from the set point, so they can stop the test and adjust before damage occurs.<\/p>\n

Third: account for the load on the test specimen. This is a mistake a lot of new test engineers make\u2014they assume the synchronization set with no load on the exciters will hold once the specimen is mounted. But every test specimen has a different mass, stiffness, and damping, and that load changes how each exciter responds. Let\u2019s use a simple example: if you have two exciters, each rated for 10 kN of force, mounted on a 100 kg steel plate with uniform mass distribution, synchronization is straightforward. But if you mount a 1,000 kg concrete beam on the same plate, the exciter closer to the beam\u2019s heavier end will have to exert more force to stay in sync, and its armature will deflect slightly more than the other. That deflection creates a small phase shift, because the exciter\u2019s driver has to account for the load. Modern control systems use real-time force feedback to adjust each exciter\u2019s output as the test runs\u2014our systems measure the force from each exciter\u2019s load cell 10,000 times per second, and adjust the phase and amplitude of each signal to compensate for changes in load. For complex structures like airplane wings, which have variable stiffness along their length, we recommend using modal testing first to map the structure\u2019s natural frequencies, then calibrate each exciter\u2019s sync pattern to match the mode shape. That way, you\u2019re not just forcing all exciters to move the same way\u2014you\u2019re forcing them to move in the exact pattern that replicates real-world vibration.<\/p>\n

Fourth: regular maintenance and monitoring of exciter components. Synchronization issues often creep in over time because of worn or damaged parts in the exciters. The most common culprits are the slip rings and brushes in larger exciters (over 50 kN force). Slip rings transfer power and control signals from the stationary body of the exciter to the moving armature, and as they wear, they create electrical noise and signal delay. A slip ring with 0.2 mm of wear can cause a phase shift of 2 degrees at 10 kHz\u2014enough to throw a large test off. We recommend inspecting slip rings every 500 hours of operation, and replacing brushes when they wear down to 20% of their original length. Another common issue is the armature\u2019s suspension springs: if a spring is corroded or stretched, it will change the armature\u2019s natural frequency, leading to phase drift over the test. We include a maintenance checklist with every exciter we sell, and our service team offers quarterly checkups for clients running 24\/7 tests, to catch these issues before they affect synchronization.<\/p>\n

I also want to address a common myth: that more exciters automatically mean better test results. That\u2019s not true if they\u2019re not synced properly. A client in Brazil once contacted us asking to add 12 more exciters to an existing 8-exciter array for testing a offshore oil rig module. When we came in to upgrade the setup, we found their control system wasn\u2019t rated for 20 exciters, and their reference clock was only 1 MHz. We recommended upgrading to our 20-exciter DSP control system with a 10 MHz clock, and calibrating the new exciters to match the existing ones. Without those upgrades, adding more exciters would have created even more synchronization errors, because the old system couldn\u2019t process the extra data fast enough. So when planning a multi-exciter setup, it\u2019s important to work with your supplier to size the control system and reference clock for the number of exciters and the test frequency range you need\u2014trying to force more exciters into an underrated system is a recipe for failure.<\/p>\n

Finally: work with a supplier that offers end-to-end sync support. As an exciter supplier, we don\u2019t just ship you a shaker and a manual\u2014we provide on-site installation, calibration, and training to make sure your multi-exciter setup is properly synchronized. We\u2019ve seen too many clients buy cheap exciters from overseas, skip the calibration step, and end up with test data they can\u2019t trust. Our exciters are designed with sync in mind: each unit comes pre-calibrated at our factory to within \u00b10.03 degrees phase error, so when you set up your array, you only need to adjust for your specific test setup, not fix inherent manufacturer errors. We also offer custom sync patterns for specialized tests, like seismic simulation, where the sync needs to match real earthquake waveforms, or acoustic testing, where phase alignment is critical to avoid sound cancellation.<\/p>\n

At the end of the day, synchronization of multiple vibration exciters isn\u2019t a one-time setup\u2014it\u2019s an ongoing process that requires the right hardware, careful calibration, and proactive maintenance. I\u2019ve been doing this for long enough to know that even the smallest oversight can lead to big problems, but with the right approach, you can get data that\u2019s accurate, reliable, and gives you the confidence you need to design better products.<\/p>\n

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If you\u2019re setting up a multi-exciter test system and want to make sure your synchronization is on point, or if you\u2019ve been dealing with sync issues that are throwing off your tests, we\u2019re here to help. Reach out to our team to discuss your specific needs, whether that\u2019s sizing a new setup, calibrating an existing array, or upgrading your control system.<\/p>\n

Spare Parts<\/a> References<\/p>\n

    \n
  1. Harris, C. M. (2004). Harris\u2019 Shock and Vibration Handbook (5th ed.). McGraw-Hill.<\/li>\n
  2. International Organization for Standardization. (2018). ISO 10816-3: Mechanical vibration \u2013 Evaluation of machine vibration by measurements on non-rotating parts \u2013 Part 3: General industrial machines.<\/li>\n
  3. Newland, D. E. (1993). An Introduction to Random Vibrations, Spectral & Wavelet Analysis (3rd ed.). Dover Publications.<\/li>\n
  4. American Society for Testing and Materials. (2020). ASTM E756-20: Standard Test Method for Measuring Vibration-Damping Properties of Materials.<\/li>\n
  5. Bendat, J. S., & Piersol, A. G. (2010). Random Data: Analysis and Measurement Procedures (4th ed.). John Wiley & Sons.<\/li>\n<\/ol>\n
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    Xinxiang Fengda Machinery Co., Ltd.<\/a>
    We’re well-known as one of the leading exciter manufacturers and suppliers in China, specialized in providing high quality customized service for global clients. We warmly welcome you to buy high-grade exciter made in China here from our factory.
    Address: No.16 Wangguanying Village, Kangcun Town, Huojia County, Xinxiang City, Henan Province, China
    E-mail: xxfdjx@163.com
    WebSite:     https:\/\/www.flipflowscreen.com\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

    If you\u2019ve ever been involved in large-scale vibration testing\u2014think seismic simulation for aerospace components, fatigue testing … How to ensure the synchronization of multiple vibration exciters?<\/span>Read more<\/a><\/p>\n","protected":false},"author":859,"featured_media":3516,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[3479],"class_list":["post-3516","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industry","tag-vibration-exciter-4228-a44024"],"_links":{"self":[{"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/posts\/3516","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/users\/859"}],"replies":[{"embeddable":true,"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/comments?post=3516"}],"version-history":[{"count":0,"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/posts\/3516\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/posts\/3516"}],"wp:attachment":[{"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/media?parent=3516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/categories?post=3516"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.custombrassandbronze.com\/blog\/wp-json\/wp\/v2\/tags?post=3516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}