High Performace Test & Measurement Solutions for INSIDER ...€¦ · and its harmonics. In addition, one can also observe the sub synchronous vibrations, which occur at frequencies

High Performace Test & Measurement Solutions for Noise & Vibration Applications


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

october 2013 | Volume 7 - Number 9

The weather is starting to turn. San Jose is beginning to see as many cold days as warm days in the week. Even Corona is no longer warm all day. Winter will soon be with us and with that the best selling season should begin. Perhaps it is the cold at-mosphere and therefore the urge to work, perhaps it is the de-sire to spend for Christmas and therefore the need to earn the money or it is the approach of the end of the Fiscal year when performance reckoning starts a new cycle, we always do our best selling in the last quarter of the year. Let’s hope this year is no exception. We need a good quarter to make this year’s tar-gets.

New software revisions for SignalCalc analyzers and SignalCalc Turbo have been released. This took a substantial software engi-neering effort and equally large testing activity by Applications Engineers. You will be pleased to see the list of improvements in both products reported here. In order to make the release hap-pen we have to cut off the software effort and it is always pos-sible that we left off a feature you consider important or a bug fix that affects one particular user. If you are faced with one of these situations please bring it up. In really important cases we can always attend to a specific item without waiting for the next release.

Corporate News

Data Physics Travels to Russia and India

Openings and Upcoming Events

SignalCalc & SignalStar New Software Release: SignalCalc Ana-lyzer Version 4.9 New Software Release: SignalCalc Turbo Version 1.5.179 Waterfall Analysis

SignalForce & SignalSound

BMW Selects Second LE-5022/DSA10-360K Shaker System for PHEV Testing The Anatomy of a Slip Table System

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Data Physics travels to Russia and IndiaIn September and October, staff from Data Physics US and Data Physics UK traveled to Russia and India to present techni-cal seminars.

Wes Mayne, Tom Reilly and Kevin McIntosh travelled to Moscow from the US and presented several semi-nars over the last week of September. The seminars were held at the offices of BLMS in Moscow, Russia.

The following week Wes arrived in India to meet with high-intensity acoustic customers. This was followed by another week of activity on underwater acoustics for which Stephen Potts, arrived from the UK to join Wes. Wes, Steve Potts and the sales team in India at-tended a symposium on underwater signature man-agement at Goa and met with several customers.

In all, the travels included seven different cities cov-ering many of Data Physics product lines over the course of three weeks.

Steve Potts (Data Physics UK) and Girish Doddamani (Data Physics India) discuss underwater acoustics applications in Goa, India

openingsData Physics is seeking qualified applicants for a number of positions in various functions at its offices in San Jose, Cali-fornia, Corona, California and Hamden, Connecticut. Please see listings in the Careers secion 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.

http://www.dataphysics.com/about-us/careers.html

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Events

Web Seminars

Evaluating Vibration Control on Thursday, November 14, 2013

Tom Villano, Senior Applications Engineer, will present a web seminar on evaluating vibration control. Vibration control is a complex task. Whether you are purchasing a new controller or verifying your controller’s performance, testing the vibration controller is an often overlooked task. Specifications and “passed” vibration tests do not really tell the user what is happening. A series of simple tests using an external dynamic signal analyzer provides users with a better un-derstanding of how the controller performs and sets an independent baseline for evaluation.

Phase Measurement Applications on Turbomachinery on Wednesday, December 4, 2013

Robert Bloomquist, Product Manager, SignalCalc Turbo, will present the advanced Turbo topic of Phase Measurement Applications on Turbomachinery. While analysis of frequency content is widely used to identify vibration malfunctions, frequency analysis alone often does not provide adequate information to the nature and root cause of machinery mal-functions such as unbalance and misalignment. An understanding of how phase is measured and applying that knowl-edge to malfunction diagnosis can provide additional valuable insight into machinery diagnostics.

Register for upcoming Data Physics Web Seminars.

View Recordings of past Data Physics Web Seminars.

http://www.dataphysics.com/news-and-events/seminars.html

https://dataphysicsevents.webex.com/ec0606l/eventcenter/recording/recordAction.do?siteurl=dataphysicsevents&theAction=archive

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Seminars

Navcon Engineering Hands-On Modal Seminars in Fullerton, CA on Nov. 5-8, 2013

Navcon Engineering provides regular training for modal testing utilizing Data Physics SignalCalc products. Using Sig-nalCalc Dynamic Signal Analyzers during the class serves as a general training on the use of the analyzer along with the fundamentals of modal testing.

The overall goal for attendees completing the class is to be able to conduct a modal test from start to finish on their own. This training is about methods and applications. Modal theory is presented from the experimentalist’s point of view. More information on the seminar content and registration can be found on the Navcon website.

IEST Seminar onsite at Data Physics in San Jose, California on Nov. 12, 2013

IEST (Institute of Environmental Sciences and Technology) and Data Physics are teaming up to provide a seminar on Multi-shaker Vibration Testing for SDOF (single axis) and MDOF (multiple axis). Thomas Reilly, Director, Product Manage-ment for SignalCalc and SignalStar, will be the instructor for the day long course. The course will include demonstrations of both multi-shaker single-axis and multi-shaker multi-axis testing. Find the course description, outline and registration information here on the IEST web page.

http://www.navcon.com/HandsOnModal.htm

http://www.iest.org/Test-Reliability-Institute/TRI-Learning-Center/TRI-Course-Catalog/Multi-shaker-Vibration-Testing-for-Single-Axis-and-MDOF

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tradeshows

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

Shock & Vibration Symposium in Atlanta (Buckhead), Georgia on November 3 to 7, 2013

The annual Shock and Vibration Symposium, also known as Shock and Vibration Exchange (SAVE), dating back to 1947, is a leading forum for the structural dynamics and vibration community to discuss new developments and on-going re-search. Topics include shock-ship testing, water shock, weapons effects (air blast, ground shock, cratering, penetration) shock physics, earthquake engineering, structural dynamics, and shock and vibration instrumentation and experiment techniques. Data Physics is a corporate sponsor of this event and located at booth P8.

New Software Release: SignalCalc Analyzer Version 4.9SignalCalc Analyzer version 4.9 has been officially released. This release contains several important enhancements and new features, along with a significant number of bug fixes. Since the last revision, the following major enhancements have taken place:

• Kaiser Bessel windows have been added. • Hv transfer function has been added to MIMO transfer function analysis. • Virtual coherence has been added to MIMO transfer function analysis. • The ability to retrieve/delete recorded files with ActiveX has been added. • An ActiveX command to fetch local bus recording sample rate has been added, in case it is not the same as the

analysis sample rate. • The throughput display has been enhanced to enable more flexibility in displays. There is improved scaling

and zooming of graphs and the ability to arrange graphs in the throughput display window. • The channel monitoring feature allows direct input of a channel number instead of picking from a list. • It is now possible to delete an engineering unit from the engineering unit table. • The Whole Body Vibration (Human Weighting Filter) has been updated to the latest ISO specification. • RPM can now be displayed versus time. • It is now possible to resize the window in the Balancing user interface. • There is now an option for an audible beep when waiting for trigger. • Chinese language environment is now supported. • Several sections were added to the manual and help.

SignalCalc Analyzer version 4.9 is available free of charge to all current users under warranty or support. The software is provided as part of any future SignalCalc Analyzer purchases.

http://www.dataphysics.com/news-and-events/tradeshows.html

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SignalCalc Analyzer Version 4.9

New Software Release: SignalCalc turbo Version 1.5.179The latest version of SignalCalc Turbo was released this month on October 7th. This version, 1.5.179, contains a number of new features and improvements. Since the last release, significant enhancements which have been implemented include:

• Improved high speed measurements: Accuracy and performance of measurements made at high machine speeds have been improved to accommodate users operating machinery at higher speeds than traditional turbomachin-ery.

• Addition & subtraction: Add or subtract vector and waveform samples from within the same run or from different runs. This is useful for validation of unbalance response rotor models and compensation of various measurements for factors such as thermal growth.

• Process variable measurement: Static channels can be configured based on proportional DC voltage signals. The software can handle signals both with and without a voltage offset.

• Sample number increase: The maximum number of Vector samples per run has been increased to 10,000. The user has the option of starting a new run automatically upon reaching the limit, and successive runs can be combined into a single, contiguous data set for analysis.

• “Smart” Default settings: Default settings have been improved to allow the user to start a new test with minimal configuration required.

• Setup now accommodates sensor orientations at any angle in one degree increments. Multiple improvements have also been incorporated into the User Manual and online Help.

The SignalCalc Turbo version 1.5.179 is available free of charge to all current users under warranty or support. The soft-ware is provided as part of any future Turbo analyzer purchases.

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SignalCalc turbo Version 1.5.179

Waterfall AnalysisAs covered in last month’s Insider, a waterfall plot provides a bird’s eye view of the vibration trends and patterns in the data as a function of speed or time. In addition to providing an overall picture, waterfall features allow a user to examine each individual frequency spectrum or order spectrum plot in detail, overlay multiple traces and compare them against maximum or RMS amplitude values as a function of shaft rotating speed or order. Each spectral line on a waterfall plot is referred to as a record and the line that is perpendicular to it is called the slice. A record or a slice can be displayed in a 2D graph beneath the waterfall plot called the waterfall child window.

Let’s take an example of a measurement that was done on a turbo charger. Figure 1 shows a cross section of a turbo charger with the compressor housing on the left and the turbine housing on the right. Vibration data was acquired with an accelerometer placed in the radial horizontal direction near the turbine housing section.

http://www.dataphysics.com/newsletters/insider/2013/09_september/Insider_2013_September.pdf

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A quick glance at the waterfall plot of the acceleration against speed (Figure 2) shows a dominant 12th order vibration. An experienced user will quickly associate this vibration with the twelve impellers on the turbine wheel as it plays a significant role influencing the 12th order and its harmonics.

In addition, one can also observe the sub synchronous vibrations, which occur at frequencies lower than the machine’s running speed. The vibration peaks that follow a curved line on an order normalized waterfall plot rep-resent a structural resonance. It may be easier to observe this on a spectrogram plot as shown in Figure 3.

Figure 1: Cross section of a typical automotive turbo charger

Figure 2: Waterfall plot showing 12th order vibration

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Figure 3: Spectrogram showing a resonance as a curved line on an order axis

Once the areas of interest are identified, an up close view of the vibration can be examined by displaying the record or slice data in the waterfall child window. 12th order and 24th order are displayed on the same graph for comparison; note that the peak amplitude on the 12th order is significantly higher than its harmonic.

Figure 4: 12th and 24th order are displayed in the waterfall child window

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A user can display a plot of the maximum or minimum response for each spectrum as a function of RPM or orders via the Waterfall functions menu. In Figure 5, the peak amplitude values for each spectrum are identified and connected on the main waterfall plot and the max values are displayed in the bottom portion of the graph as a function of or-ders. The same information can be displayed as a function of the shaft rotating speed.

Figure 5: Peak amplitude of each spectrum plotted as a function of shaft rotating speed

The waterfall function menu also allows the selection of any number of orders and their harmonics to be tagged on the waterfall and displayed in the child window. The selected orders can be compared against the Min, Max or RMS values of all the orders or the selected orders. 4 user selected orders are overlaid and compared against the RMS values of the spectra as a function of RPM in figure 7.

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Figure 6: Waterfall Functions menu

Figure 7: User selected orders are displayed and compared against RmS spectral values

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BmW Selects Second lE-5022/DSA10-360K Shaker System for PhEV testing

BmW eDrive

As was briefly mentioned in the September issue of the Insider, Data Physics Germany has secured an order for a new SignalForce LE-5022/DSA10-360K shaker system combined with a SignalStar Vector controller. The new shaker system will be delivered and installed at the BMW Brilliance Automotive (BBA) facility in Shenyang, China. BBA is a joint ven-ture with BMW and Brilliance Automotive producing cars for the Chinese market.

The BBA facility will begin to develop and manufacture Plug-in Hybrid Electric Vehicles (PHEV) and will need to have the shaker capacity to perform the same durability tests performed at the BMW Engineering Center in Germany.

This will be the second system BMW has purchased from Data Physics for testing the heavier payloads associated with the PHEV technology. The first system was commissioned in the BMW Engineering and Development Center in Munich, Germany. With this order BMW will now have a total of four SignalForce water cooled shaker systems. This is significant in that they had previously used primarily LDS shakers in their Engineering and Durability test groups until they purchased their first Data Physics SignalForce system.

The new system, scheduled for commissioning next summer, will include a specially designed 80" x 140" slip table with Hydrostatic T-Film Bearings and a low profile head expander designed for low frequency operation to 200 Hz. Both tables will be fitted with thermal barriers for operation in a climatic chamber.

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the Anatomy of a Slip table SystemOften if users are required to conduct three mutually orthogonal axes of vibration testing, a slip table will be needed for a portion of the testing. This is typically in the transverse and longitudinal axes. The type of table required to con-duct a test is dependent upon the user’s test parameters and the physical size of the components being tested. These parameters were covered in previous Insider articles (February 2012 Insider).

The slip table assemblies vary in their guidance options. The quality of the assembly and the guidance used deter-mines the performance and long term reliability of the table. SignalForce shakers stand out because of the many options that are offered for configuration. Instead of offering a system from a limited choice of options, Data Physics offers a tailor-made system with high quality components and construction.

While previous articles have focused on the guidance of the table systems, this article focuses on the entire assembly. All of the components of a slip table assembly are outlined to provide the best overview of the entire system.

Most SignalForce slip tables are configured with the shaker as a monobase slip table assembly. The monobase as-sembly integrates the shaker trunnion into the slip table. The obvious reason for choosing a monobase assembly is to avoid alignment problems over time. Figure 1 illustrates a Monobase Assembly that is utilizing T-Film Bearings for guidance.

http://www.dataphysics.com/newsletters/insider/2012/february/Insider_2012_February_Tahoe.pdf

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One of the items of the table assembly that is commonly underappreciated is the actual base assembly. The base as-sembly is the steel construct that holds and supports the shaker and/or guidance assemblies. If this assembly is faulty, you can provide the best guidance available and it will be useless because the base assembly will not support the dynamic loads induced during testing.

• Base Assembly – This assembly consists of a rigid steel frame. The steel frame is welded with rebar added to the un-derside to act as a reinforcement structure for the concrete that will be poured into the complete underside of the base. The use of reinforced concrete adds mass to the assembly. The added mass makes the assembly more effec-tive as a reaction mass to reduce the (unwanted) motion of the shaker body.

• moat – The moat provides a reservoir that holds the hydraulic fluid that flows through the table system. The hy-draulic fluid acts as a coolant, lubricant and moment restraint during dynamic testing.

• hydraulic Pump – The pump shown in the Figure 1 is used with T-Film bearings and it pumps low pressure hydrau-lic oil through the table system at 600 psi at the bearings. Depending on the table’s guidance assembly, the system will utilize different types of pumps. If the Kimball 710 Journal bearings are utilized in the table system, then a self-contained upright high pressure hydraulic power supply will be used. This pump assembly provides up to 3,000 psi to the bearing assemblies. While the two pumps mentioned allow the table systems to provide excellent moment restraint for heavy masses, our standard oil pump for the linear guide assemblies and the guided oil film (GOFT) systems provide reasonable moment restraint as well.

• Granite – Except for the T-Film table system, all SignalForce slip tables are fitted with a natural granite slip surface. As explained in the August 2012, Volume 6, Number 7, “To Be Natural or Synthetic” Insider Article, slip tables are constructed with natural granite surfaces because of its superior attributes when compared to our competitors’ synthetic granite offerings.

• table Guidance – The guidance for the table system is matched with the current needs of the customer as well as their future needs. The test mass and its dynamic characteristics are the main factors in determining what type of table guidance is required for the table system.

The guidance assemblies that are available from Data Physics are Guided Oil Film, Linear Guides, High Pressure 710 Journal Bearings and T-Film Bearings. The system shown in Figure 1 is equipped with a T-Film bearing guidance as-sembly.

• Slip Plate – The slip plate is the mounting surface that allows the customer to test their components. The slip plate is constructed of magnesium. Due to its excellent damping characteristics, magnesium is used for slip plates and head expanders. Another great characteristic of magnesium is that it is lightweight.

• Guide Rails – The guide rails are added to prevent unwanted debris from entering the moat. These rails also pro-vide an aesthetically pleasing finish to the assembly.

• hoist Rings – Swivel hoist rings are included with the table system so that the user has the option of lifting the system with an overhead crane or fork-lift.

http://www.dataphysics.com/newsletters/insider/2012/august/Insider_2012_August.pdf

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• Air Isolators – Air isolators are sized and positioned so that the least amount of vibration is transferred into the customer’s floor. It is impossible to prevent the transmission of all vibration into the facility floor when using a monobase assembly. The overall level of vibration can, however, be minimized by the combined use of Lin-E-Air isolation systems at the shaker trunnion location and air isolation under the monobase assembly.

The newly designed monobase assemblies allow for the innermost air isolators to move towards the shaker or away from the shaker to compensate for center of gravity changes that occur with various test articles. The new placement provides better overall support and minimizes rocking motion that might be experienced as a result of high displace-ment testing.

ContributorsRobert Bloomquist, Product Manager, SignalCalc TurboAlfred Johnson, Applications EngineerBourke MacDonald, Marketing Communications Specialist Kevin McIntosh, Director, Product Management, SignalForce and SignalSoundThomas Reilly, Director, Product Management for SignalCalc and SignalStarKalyan Vitta, Senior Applications EngineerRussell Zuppo, Director, MarketingManaging Editor: Sri Welaratna, PhD, President and Chief Executive Officer

High Performace Test & Measurement Solutions for INSIDER ...€¦ · and its harmonics. In addition, one can also observe the sub synchronous vibrations, which occur at frequencies

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