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High Performace Test & Measurement Solutions for Noise & Vibration Applications High Performace Test & Measurement Solutions for Noise & Vibration Applications Data Physics Corporation (408) 437 0100 | www.dataphysics.com High Performace Test & Measurement Solutions for Noise & Vibration Applications High Performace Test & Measurement Solutions for Noise & Vibration Applications INSIDER WELCOME TO THE INSIDER The Data Physics Internal Newsletter May 2013 | Volume 7 - Number 5 In this issue we introduce the new SignalForce LE-1316-3/DSA10- 100K Electrodynamic Shaker System and refer to a notable press release by NetSuite that recognizes Data Physics for 10 years of global growth. There are three tradeshows in June and the new schedule of web seminars includes five events through August. The SignalCalc and SignalStar section highlights the selection of SignalCalc Turbo by industry leader Solar Turbines and reports the selection of SignalCalc Savant by an institute of metrology sci- ence in China. A product focused article compares and contrasts SignalStar Scalar and SignalStar Vector, helping users select the correct vibration controller for their application. There is a Signal- Force article detailing qualification testing on a 3 inch (76.2mm) peak-peak version of the popular LE-2016 shaker system while another article explains overturning moments in vibration test- ing. The first quarter of the year has drawn to a close with sales in- creasing by better than 50% over the same period last year. Of course we don’t expect such heady numbers to sustain over the long haul, but it does make for a nice start to the year. With the US recession firmly behind us and signs of strength in the high growth economies of the world, we are looking forward to strong results this year. Corporate News Data Physics Recognized by Net- Suite for 10 Years of Global Growth Openings and Upcoming Events SignalCalc & SignalStar Solar Turbines Selects SignalCalc Turbo Shaanxi Institute of Metrology Chooses SignalCalc Savant A Comparison: SignalStar Scalar vs. SignalStar Vector SignalForce & SignalSound Introducing the LE-1316-3/DSA10- 100K LE-2016-3/DSA10-200K Shaker System Passes Qualification Tests Overturning Moments in Vibration Testing INSIDER You may have noticed that we are running regular web seminars covering all aspects of our technology and hope that you are able to make use of these events for refreshing your own knowl- edge as well as for introducing your prospective customers to the subjects. If you wish other topics to be covered in these semi- nars please mail your requests to insider@dataphysics.com.
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  • High Performace Test & Measurement Solutions for Noise & Vibration Applications

    High Performace Test & Measurement Solutions for Noise & Vibration Applications

    Data Physics Corporation(408) 437 0100 | www.dataphysics.com

    High Performace Test & Measurement Solutions for Noise & Vibration Applications

    High Performace Test & Measurement Solutions for Noise & Vibration Applications

    INSIDER

    W E lCo m E to t h E I N S I D E RThe Data Physics Internal Newsletter

    may 2013 | Volume 7 - Number 5

    In this issue we introduce the new SignalForce LE-1316-3/DSA10-100K Electrodynamic Shaker System and refer to a notable press release by NetSuite that recognizes Data Physics for 10 years of global growth. There are three tradeshows in June and the new schedule of web seminars includes five events through August. The SignalCalc and SignalStar section highlights the selection of SignalCalc Turbo by industry leader Solar Turbines and reports the selection of SignalCalc Savant by an institute of metrology sci-ence in China. A product focused article compares and contrasts SignalStar Scalar and SignalStar Vector, helping users select the correct vibration controller for their application. There is a Signal-Force article detailing qualification testing on a 3 inch (76.2mm) peak-peak version of the popular LE-2016 shaker system while another article explains overturning moments in vibration test-ing.

    The first quarter of the year has drawn to a close with sales in-creasing by better than 50% over the same period last year. Of course we dont expect such heady numbers to sustain over the long haul, but it does make for a nice start to the year. With the US recession firmly behind us and signs of strength in the high growth economies of the world, we are looking forward to strong results this year.

    Corporate News

    Data Physics Recognized by Net-Suite for 10 Years of Global Growth

    Openings and Upcoming Events

    SignalCalc & SignalStar

    Solar Turbines Selects SignalCalc Turbo

    Shaanxi Institute of Metrology Chooses SignalCalc Savant

    A Comparison: SignalStar Scalar vs. SignalStar Vector

    SignalForce & SignalSound

    Introducing the LE-1316-3/DSA10-100K

    LE-2016-3/DSA10-200K Shaker System Passes Qualification Tests

    Overturning Moments in Vibration Testing

    INSIDER

    You may have noticed that we are running regular web seminars covering all aspects of our technology and hope that you are able to make use of these events for refreshing your own knowl-edge as well as for introducing your prospective customers to the subjects. If you wish other topics to be covered in these semi-nars please mail your requests to insider@dataphysics.com.

    mailto:insider@dataphysics.com

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    Data Physics Corporation(408) 437 0100 | www.dataphysics.com

    Data Physics Recognized by NetSuite for 10 Years of Global Growth

    Data Physics Corporation was recently featured by NetSuite in a press release titled Manufacturer of Industrial Sound and Vibration Testing Equipment Marks 10 Years of Global Growth on NetSuite. Netsuite is a leading company in the market of cloud-based ERP (Enterprise Resource Planning) software solutions. The press release was distributed by PR Newswire and picked up by MarketWatch of the Wall Street Journal, Yahoo! Finance and other media outlets. Visit the Data Physics web site to read the news.

    openings

    Data Physics is seeking qualified applicants for a number of positions in various functions at its offices in San Jose, California, Corona, California and Hamden, Connecticut. Please see listings in the Careers section of the Data Physics website for details. You are invited to refer suitable candidates with the promise of a monetary reward for the successful hiring of your referred candidates. The size of the reward will vary between $250 and $1000 depending on the position.

    Upcoming Events

    Web Seminars

    Kinematic Transformation for Matrix Multishaker Control on Thursday, June 6, 2013

    Thomas Reilly, Director of Product Management, SignalCalc and SignalStar, will present this web seminar on kinematic transformation. The seminar will cover the basics of kinematic transformation for multishaker control and how it is used in typical situations. Kinematic transformation uses rigid body kinematics to transform multiple measurements or drive signals to the rigid body translation and rotational degrees of freedom. Examples of real world application of kinematic transformation to multi degree of freedom vibration testing will be given.

    Understanding the Shock Response Spectrum (SRS) on Thursday, July 11, 2013

    Kalyan Vitta, Senior Applications Engineer, will present the origination of SRS and why it is important to understand and analyze the shock response of a structure. This seminar will also cover the different SRS applications and how SRS test-ing provides the ability to synthesize a time waveform from a SRS profile that can be controlled on electro dynamic or electro hydraulic shakers in a consistent manner.

    http://www.dataphysics.com/data-physics-recognized-by-netsuite-for-10-years-of-global-growth/http://www.dataphysics.com/about-us/careers.html

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    Shaker Selection Basics on Thursday, July 23, 2013

    Kevin W. McIntosh, Director of Product Management for the SignalForce and SignalSound Product Lines, will cover basics on proper shaker selection. Kevin has more than 30 years of experience in the vibration test industry, both in ser-vohydraulic and electrodynamic shakers. Kevin is currently the Chairman of the IEST Shaker Selection Working Group, writing the best practices document for the Institute of Environmental Sciences and Technology.

    High Intensity Acoustic Test Systems on Thursday, August 8, 2013

    Wes Mayne III, Product Manager, Acoustic Test Systems, will provide a quick overview of some important aspects of RAT-Fs and PWTs, including their general configuration, the specification of test spectra, chamber low-frequency response and uniformity, auxiliary systems such as cranes, and other topics.

    Introduction to Turbomachinery Vibration Analysis on Tuesday, August 20, 2013

    Robert Bloomquist, Product Manager, SignalCalc Turbo, will cover the basics of vibration analysis on large rotating ma-chinery. He will lead you through a tour of basic considerations and requirements for turbomachinery vibration analysis. You will learn the challenges of turbomachinery vibration analysis compared to smaller general purpose machinery, how to make effective measurements, and what to look for when analyzing behavior on these large, critical machines. Register for upcoming Data Physics Web Seminars.

    View Recordings of past Data Physics Web Seminars.

    tradeshows

    Visit the Data Physics website for a complete list of 2013 tradeshows.

    Automotive Testing Expo Europe 2013 at Stuttgart, Germany on June 4 to 6, 2013

    Automotive Testing Expo is a leading event for every aspect of vehicle, motorcycle and components testing, validation, reliability assessment, quality evaluation and related data capture and analysis. Data Physics (Deutschland) will once again be on hand at booth 1754. The well attended event displays the latest technologies in the areas of vehicle, motor-cycle and components testing, evaluation, quality engineering and validation.

    ASME Turbo Expo at San Antonio, Texas on June 3 to 7, 2013

    The well regarded turbomachinery industry event includes a technical conference and expo. This year the location is in San Antonio, Texas. ASME (American Society of Mechanical Engineers) Turbo brings together experts from various fields including gas turbines, steam turbines, wind turbines, fans and blowers, solar brayton and rankine cycle and supercriti-cal CO2. Rob Bloomquist, Product Manager for SignalCalc Turbo, will be on hand at booth 412.

    http://www.dataphysics.com/news-and-events/seminars.htmlhttps://dataphysicsevents.webex.com/ec0606l/eventcenter/recording/recordAction.do?siteurl=dataphysicsevents&theAction=archivehttp://www.dataphysics.com/news-and-events/tradeshows.html

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    Vibration Institute at Jacksonville, Florida on June 19 to 21, 2013

    The 2013 Annual Training Conference and Expo will cover topics such as identification, analysis, and correction tech-niques such as balancing and alignment. The focus will be on techniques used in vibration analysis, basic rotor dynam-ics, operating deflection shapes, time waveform analysis, machine isolation, and machine monitoring. Data Physics will be at booth 14.

    Noise-Con at Denver, Colorado on August 26-28, 2013

    Noise-Con 2013 conference and exposition will be held in conjunction with the 2013 International Wind Turbine Noise Conference. The event focuses on the latest in technology and services in the areas of noise and vibration. Topics include building acoustics and noise control, product noise emissions, community and environmental noise, industrial noise, motor vehicle noise, and air and space system noise and vibration. Data Physics will be at booth 21.

    Solar turbines Selects SignalCalc turbo

    Solar Turbines is a significant new addition to the growing list of global turbomachinery manufacturers using the Sig-nalCalc Turbo system in their businesses. The Solar Turbines regional field services group based in Houston, Texas, USA, recently placed orders for SignalCalc Turbo with a 16-channel Abacus and a 4-channel Quattro. Additional orders for SignalCalc Turbo and training are expected in the coming months, as the Houston-based group plans to fully outfit their team with the tools and know-how for comprehensive vibration measurement and analysis on Solar machines installed at customer sites in their region.

    Prior to purchasing SignalCalc Turbo, this regional field services group of Solar Turbines had primarily been relying on small, two-channel portable analyzers for baseline data collection and troubleshooting. These two-channel analyzers are designed primarily for route-based data collection in industrial environments. The analyzers lack the diagnostic ca-pabilities necessary for comprehensive analysis of large, critical rotating machinery with fluid-film bearings. With the ad-dition of SignalCalc Turbo to their toolkit, the field services group can now handle machine run-up coast-down, substan-tially improving their diagnostic capabilities. This includes orbit and shaft centerline analysis from permanently installed X-Y pairs of proximity probes on their machines. And with the 16-channel Abacus, they can now meet the vibration measurement channel requirements of a fully instrumented gas turbine-driven compressor train. Such a machine has 4 sets of X-Y proximity probes installed on the gas generator and power turbine sections, 2 sets of X-Y proximity probes on the driven centrifugal compressor, plus 2 tachometer sensors.

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    Solar turbines Gas turbine-Driven Compressor train During Preparation for testing (Source: http://mysolar.cat.com)

    A subsidiary of Caterpillar, Inc., Solar Turbines is based in San Diego, California, USA. They manufacture mid-range gas turbine and centrifugal compressors primarily for oil and gas production and transmission applications. Solar Turbines gas turbines are also used as drivers by the power generation industry. Near their corporate headquarters, Solar oper-ates a large test facility where assembled units are factory tested prior to shipment to customers. According to the Solar Turbines website, Solar Turbines delivers more than 70% of their units to customer sites outside the USA.

    Solar Turbines and other global turbomachinery manufacturers are strategic customers for Data Physics. Because vibra-tion measurement and analysis are vital capabilities for them, used in the factory test environment as well as the field diagnostic service situation, there is great potential for exposure of SignalCalc Turbo to end-user customers through their own activities. There is no better endorsement for a product than being seen in use by other trusted users.

    Shaanxi Institute of metrology Chooses SignalCalc Savant

    Shaanxi Province Institute of Metrology Science is anticipating the use of the two SignalCalc Savant systems they pur-chased. The measurement and standards organization in western China recently ordered a 64 channel Savant and a 56 channel Savant. The two Savant systems can, of course, be combined to form a 120 channel system.

    The SignalCalc system was selected over competition after many months of demonstrating the capabilities of Signal-Calc Savant. The Data Physics China team recognizes that a key to success was in arranging a visit with existing Savant users in Xian. This visit and the months of demonstration and relationship building gave the customer confidence in the Data Physics solution.

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    The institute plans to use the system to measure large scale structural vibration on buildings and isolation systems to evaluate the response to shock events and other vibration. In addition to being the official metrology establishment in the region, the institute provides guidance for measurement work needed in cities and districts and performs measure-ment and technology consulting work. As a customer of Data Physics, Shaanxi Institute of Metrology joins other official metrology organizations such as NIST (in the United States) and PTB (in Germany) using Data Physics dynamic signal analyzers and vibration controllers.

    A Comparison: SignalStar Scalar vs. SignalStar Vector

    Each and every customer has his or her own way of evaluating controller needs. In some cases price is the leading factor in their decision. For this reason many gravitate towards SignalStar Scalar as their solution. This is reflected in the sales data. In the past year Data Physics has delivered slightly more Scalar controllers than Vector controllers.

    What exactly does one miss out on by purchasing the entry level Scalar instead of the Vector? The most obvious answer is expandability while Scalar is limited to 8 channels, Vector can expand up to 32. The Vector can also transform to a Matrix in a single Abacus or multiple Abacus chassis for an even higher channel count. Channel count and expandability alone is enough to entice many users into the Vector sphere.

    The actual signal processing hardware provided in the Scalar and Vector platforms is nearly identical. However, the Sca-lar is often configured to act as both a controller and a host PC. As a result, Scalar may be limited in some computation-ally intensive areas. While these dissimilarities in hardware capability often go unnoticed during normal usage, there are many software differences between Vector and Scalar which do not. These can be looked at in two general categories: system wide differences, and those which affect one particular test type.

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    System Wide Software Differences

    There are many system-wide features Vector has which are not available or sold as options in Scalar. One such difference is the graphing library. The Scalar graphing library allows for three layouts with up to 16 plots per layout and 8 signals per plot. Vector allows for more layouts and up to 32 graphs per layout an upgrade which is optional in Scalar. This limitation becomes important as channel count increases, especially with 8 channel count Scalars.

    Throughput recording to disk is a useful tool for post processing and analyzing vibration control data. Many R&D or mili-tary test labs find it useful, and some aerospace facilities require it. Vector has an available throughput to disk recorder, and has the ability to completely post process the recorded data in any SignalCalc software module. Scalar on the other hand does not offer throughput to disk and its SignalCalc capabilities are very limited.

    table 1: General Differences between Scalar and Vector

    SCALAR VECTORlayouts Standard: 3 layouts, 16 graphs per

    layout, 8 traces per graphOptional: >50 layouts, 32 graphs per layout, >32 traces per graph

    >50 layouts, 32 graphs per layout, >32 traces per graph

    Shaker list One shakers parameters can be entered in each test

    A shaker database is saved with the ability to add parameters for any number of shakers

    throughput Recording

    Not available Optional

    Analyzer Limited in scope and optional Optional

    Channels 2-8 4-32

    test types Available

    Sine, Random, Sine on Random, Random on Random, Shock, SRS, Replicator

    Sine, Random, Sine on Random, Random on Random, Shock, SRS, Replicator, Multi Frequency Sine

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    Sine Control

    The Vector sine control module is slightly more advanced than that of Scalar. In the early days of marketing Scalar, sine control was sold without sine tracking filters. There may be Scalar systems in the field which do not have the filter mode in their channel table. Today Scalar sine control is always sold with tracking filters, mimicking Vector sine control. Scalars without sine tracking filters can be upgraded.

    The Scalar sine module can run up to 5kHz with the option to upgrade to 20kHz. The Vector sine module operates to 20kHz standard. This capability may be of interest to consumer electronic customers running on small shakers. Other items standard on Vector but optional on Scalar include limit channels, reference import and average control; all useful tools for R&D, customers dealing with sensitive or large test structures and environmental test labs.

    table 2: Differences between Scalar and Vector Sine Control

    SCALAR VECTOR

    tracking Filter Standard (with DP740-20A) Standard

    limit Channels Optional Standard

    Reference Import Optional Standard

    high Frequency Standard: 5kHzOptional: 20kHz optional

    Standard: 20kHzOptional: 30kHz optional

    Average Control Optional Standard

    Random and Mixed Mode Control

    The Vector random test types come standard with more frequency lines and a higher frequency range than Scalars random. Vector also includes limit channels, profile importing (from an external file) and average control. The extended FFT settings, limit channels, average control and profile importing can all be purchased separately as options for Scalar.

    The most commonly added option is average control. Average control is often useful for larger items and difficult to control tests. Some random test specifications even require average control.

    The Vector also includes an extra measurement capability. These measurements are a test within the test. They allow the user to setup measurements that are independent from the control measurements and specify specific averaging.

    All of the options in random control also apply to the mixed mode control types. Note that to add sine-on-random or random-on-random to the Scalar, the system must include both random control and the high resolution option.

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    table 3: Differences between Scalar and Vector Random and mixed mode Control

    SCALAR VECTOR

    lines of Resolution Standard: 800Optional: 6400

    6400

    limit Channels Optional Standard

    Reference Import Optional Standard

    high Frequency Standard: 5kHzOptional: 20kHz optional

    20kHz

    Average Control Optional Standard

    measurements Not Available Standard

    Number of mixed mode Components

    16 32

    Classical Shock and SRS Control

    The Vector classical shock and SRS control has a larger standard block size than is available with the Scalar. This can be-come an issue when running longer or higher frequency shock or SRS pulses. However, just like other FFT limitations in Scalar, this block size can be optionally increased.

    table 4: Differences between Scalar and Vector Classical Shock and SRS Control

    SCALAR VECTOR

    Frame Size Standard: 8,192Optional: 65,536

    65,536

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    Replicator

    Unlike other test modules, Scalar time replication cannot be upgraded to be comparable to the Vector time replication capability.

    The first of two major differences is Vectors capability to sequence time histories. Vector replicator allows users to break up imported time histories into smaller sections, called sequences. The sequences can then be organized and run with different control settings for each. This makes it easy to schedule tests from different parts of time histories. Scalar only allows users to create one large sequence from imported files.

    The second, and more fundamental, difference between Scalar and Vector time replication is the available control strat-egies. The set of sequences in Vector can be run with live realtime control or by replaying an iterated drive signal. Replay-ing drive signals uses an iterated signal that is obtained by repeatedly replaying and adjusting the entire time history prior to performing the test. This process reduces the error of the drive file considerably.

    Scalar only provides the capability to run realtime control. This limitation may make Scalar time replication less effective for time signals with large differences in amplitude or on test with non-linear behavior. While both Scalar and Vector are capable of time replication, Vector replicator is a much more flexible and capable product than Scalar replicator. Cus-tomers who are going to primarily be running replicator should take this into consideration.

    table 5: Differences between Scalar and Vector Replicator

    SCALAR VECTOR

    Control Schemes Realtime frequency based control Realtime frequency based control or drive files

    Sequencing No test sequencing Time histories can be split and run in sequences

    Scalar is a viable solution for some, but not all, applications. Scalar software was designed to be entry level by not includ-ing some of the advanced and computationally intensive features and by making some of the standard Vector bells and whistles optional. It is well suited for predefined production-style testing. Users performing development or qualifica-tion work, along with users that need flexibility such as independent test labs, would often be better served with the standard feature set of the Vector. Understanding the differences between Scalar and Vector will help in selecting the right controller.

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    Introducing the lE-1316-3/DSA10-100K: 60 kN Force with 76.2 mm Displacement

    In May, Data Physics formally launched the new SignalForce LE-1316-3/DSA10-100K Electrodynamic Shaker System. The new air cooled shaker is capable of 13,500 lbf (60 kN) for sine and random. The shaker, whose operating frequency ranges up to 3 kHz, can produce a maximum displacement of 3.0 inches (76.2 mm) peak-to-peak and a maximum con-tinuous operating velocity of 79 ips (2.0 m/s). The shaker can operate continuously at 2.5 inches (63.5 mm).

    Newer standards emerging from the aerospace, military, and automotive industries require this extended displacement for high level shock and harsh, low frequency random tests. For instance the MIL-STD-810G contains harsh random profiles and US automotive manufacturers Ford and General Motors are requiring 100g, 11 ms shock. Enabling users to perform these tests on air cooled shakers results in a cost savings compared to using water cooled shakers.

    The LE-1316-3 is designed to make SignalForce air cooled shakers more competitive. The shaker comes equipped with a cast aluminum hand-wound armature, opto-pneumatic load support and dual bearing axial guidance. The proprietary J-type flexures combined with dual bearing guidance provide superior dynamic cross axis and rotational stiffness. Ad-ditionally, the armature for the LE-1316-3 shaker is a high strength aluminum casting, not welded or assembled, for superior durability.

    The LE-1316-3/DSA10-100K was announced to the public on May 9, 2013. Visit the Data Physics web site to see the news.

    lE-2016-3/DSA10-200K Shaker System Passes Qualification tests

    The Applications Engineering Team at Data Physics Corona operation recently performed qualification testing on a 3 inch (76.2mm) peak-peak version of the popular LE-2016 shaker system. The system was successfully tested to full dis-placement, velocity, and force in Sine, Random and Shock modes. The testing was done in both vertical and horizontal axes.

    The testing went exceptionally well, with no measured degradation in performance. The proprietary J-type flexures have once again proven to be a viable solution for high displacement tests, while still offering excellent cross-axis and rotational restraint.

    Demanding MIL-STD-810G tracked vehicle random profiles and high acceleration shock profiles have been the driving force behind extending the displacement of the SignalForce shaker systems. Figures 1 shows the MIL-STD-810G profiles and results.

    Testing on the LE-2016-3 included 100g, 11 mSec shock pulses with payloads up to 450 lbs. (205 kg). The velocity achieved during this high acceleration shock test was in excess of 160 inches/second (4 m/sec).

    http://www.dataphysics.com/data-physics-corporation-adds-60-kn-shaker-to-signalforce-line-of-electrodynamic-shakers/

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    Figure 1: mIl-StD-810G method 514.6C-VI. Category 4 Composite wheeled vehicle vibration exposure Ver-tical, transverse and longitudinal

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    overturning moments in Vibration testing

    Overturning moments are caused by moving masses whose center of gravity is offset from the center of gravity of the shaker. The center of gravity of the shaker lies on the geometric center line of the shaker. The offset acts as an arm and the reaction force of the moving mass with the arm results in a moment. The overturning moment increases with accel-eration. SignalForce shakers provide load constraint in the presence of overturning moments to ensure continued safe operation of the shaker. For large loads and loads with large center of gravity offsets, the overturning moment needs to be checked against the shaker or slip table capabilities. External head expander guidance or more slip table bearing support may be required if the overturning moment of the standard configurations are exceeded.

    The two most common cases to consider are vertical operation with the DUT on a head expander and horizontal op-eration with the DUT on a slip table. The following discussion analyzes these two cases, comparing them with bearing support. Note that these calculations assume that the body is rigid, which is not strictly true for the entire range of fre-quency of operation.

    Vertical Operation

    The vertical operation is shown in Figure 1 below. The center of gravity of all SignalForce head expanders is aligned to the center line of the shaker. In this example, the DUTs center of gravity is offset from the center line. The moments caused by this offset can be harmful to the shaker. High moments can lead to damaged flexures and bearings. If the moment is high enough, the offset load can even lead to damaged armatures and field coils.

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    To illustrate this point, consider a mass of 230 lbs and an offset of 5 inches. The profile being used has different accel-eration levels with a maximum acceleration of 12 g. The maximum moment produced is:

    230 lbs x 12 g x 5 in = 13,800 in-lbs

    Horizontal Operation

    The horizontal operation of the shaker can also cause overturning moments. Figure 3 below shows an example of the slip table with DUT mounted on top. The center of gravity of the DUT always has an offset due to the setup. In addition to wear on the shaker bearings, the moment could cause an unrestrained slip table to lift from and slap against the granite slip surface.

    Figure 4: Vector Diagram of horizontal Case

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    The horizontal moment is calculated in a similar fashion to the vertical operation. For this example, assume many pro-files are run on this shaker including a sine of 20 g and a random of 15 g with peak values set to 3 sigma. The same 230 lb load will be used that has a center of gravity that is 18 inches above the shaker center line.

    Sine Case: 20 g pkRandom Case: 15 g * 3 sigma = 45 g pk

    It follows that the maximum moment will occur with random profile generating 45 g acceleration and not the 20g sine. The maximum moment is:

    230 lbs * 18 in * 45g = 186,300 in-lbs

    The overturning moments caused in vertical operation are restrained with the use of load support. Overturning mo-ment restraint in horizontal operation is provided by adding bearings or changing the type of bearings used in the slip table.

    Contributors

    Robert Bloomquist, Product Manager, SignalCalc TurboMin Dai, Manager, Data Physics ChinaBourke MacDonald, Marketing Communications Specialist Kevin McIntosh, Director, Product Management, SignalForce and SignalSoundSai Mullapudi, Applications Engineer Raman Sridharan, Applications EngineerEditor: Russell Zuppo, Director, MarketingManaging Editor: Sri Welaratna, PhD, President and Chief Executive Officer