Today's most complete PC­based structural analysis system, the STAR System™ combines the latest structural analysis technology with an intuitive interface based on Microsoft~Windows~. From operating deflection shapes to modal and time­domain analysis, from advanced analysis of multi-reference parameter estimation to structural dynamics modifications, STAR does it all.

The STAR System, the single most comprehensive solution for structural dynamic test.

Take Advantage of the All­ln­One Source for Structural Test
Combining powerful technical capabilities, networking, and an easy­to­use interface based on Microsoft Windows, the STAR System is unparalleled in its flexibility for handling a variety of structural test requirements.

The STAR System integrates all the engineering capabilities you require­from time-domain animation and operating deflection shape analysis to advanced modal analysis. Each of its dynamic analysis methods illuminates a specific aspect of a structure's dynamic behavior. Built­in animation capabilities let you clearly visualize structural behavior and identify problems.

You can leverage your existing investment in hardware and software because the STAR System imports data from other systems and exports it to a variety of applications. For example, you can import test data directly from your instruments using the GPIB interface or from many common databases, and you can copy data and graphics for pasting into word processing, presentation, and spreadsheet applications.

And the modular design of the STAR System flexibly accommodates your changing requirements. You can begin with the tools you need today, then add more capabilities as your testing needs evolve.

The STAR System features intuitive pull­down menus and the point­and­click interface of the Windows operating environment, minimizing training time and expense. Using the powerful data acquisition and analysis modules in the STAR System requires little more than clicking icons on the tool bar and navigating through the logical menu structure. New and occasional users can guide themselves step­by­step through the structural test process by referring to the STAR Gateway™, a process oriented interactive graphic.

Ale STAR System also accepts measurement data saved to disk by popular systems. You import the data into the STAR System using a data disk translator, which allows you to select from a variety of measurement labeling methods and data types. Batch operation speeds the process.

To simplify documentation of test results, all measurement data in the STAR System includes a descriptive header and a filename that indicates measurement location, type, and other parameters.

The STAR System measurement display is designed specifically for the time­ and frequency­based measurements common to structural analysis. The display is interactive, enabling you to manipulate real and complex valued data and display it in full, overlay, or split formats.

To highlight key results you can take advantage of zooming, automatic or manual scaling, grid tics, and many other display options. Then, you can copy graphics and data and paste them into presentation or word­processing applications for reports, or spreadsheet applications for custom analysis.

The STAR System provides an extensive set of measurement math calculation options for time­ or frequency­based data. For example, you can use measurement display data blocks to perform operations such as FFT, IFFT, add, subtract, multiply, divide, conjugate, integrate, differentiate, and invert. Simply move the cursors to indicate whether you want to execute the operations on all or part of a measurement. To focus investigation on areas of interest, you can even define your own time­domain band­pass, low­pass, or high­pass filters.

Animation of time history data shows the structure's actual movement over a measured time period. This is often the first step in solving vibration­ or motion related problems. Time-domain analysis is uniquely suited for transient, nonlinear, or frequency­variant events-for example, machine run­up/coast-down; shock response; or dynamic changes in mass, stiffness, or damping during the measurement period.

The STAR System's rich feature set allows you to efficiently analyze and animate results for fast problem solving. For example, accurate integration of data to displacement units shows actual motion and helps you locate areas of maximum deflection. Digital time­domain frequency filtering lets you isolate problem areas to animate for further study. And Batch Inverse FFT calculations on Frequency Response Function (FRF) measurement data sets enable you to animate structural motion in response to an impulse. The STAR System processes the impulse response functions as regular time histories that can be digitally filtered and integrated.

The STAR System generates scaled operating deflection shapes by using autopower and cross power spectra in addition to transmissibility measurements- all with the same instrumentation setup. The result: You get accurate deflection shapes that are scaled to acceleration, velocity, displacement, or g's. These deflection shapes enable you to compare the amplitude of motion for different shapes-a capability not possible with transmissibility measurements alone.

The STAR System uses special algorithms to track either peaks or frequencies. You can input a specific frequency at which you want to see the structure's shape. Or, by placing a band around a peak, you can track the peak frequency in the band. Most machines change speed slightly during operation; without the peak tracking technique, it is nearly impossible to obtain accurate operating deflection shapes for machines that drift in speed by as little as one frequency resolution step.

Creating a modal model from FRF measurements involves two steps: identifying the mode locations and accurately estimating the modal parameters of frequency, damping, and residues. The STAR System provides both capabilities, giving you a variety of options.

To identify mode locations, the STAR System uses hybrid summation functions that help locate all of the modes in a data set, even if some are not present on a given measurement.

To accurately estimate modal parameters, the STAR System provides the widest variety of curve fitters in the industry.

Simple peak curve fitting methods (coincident, quadrature, and complex peak) provide quick insight into mode shapes. Local single mode (SDOF) and multiple mode (MDOF) polynomial curve fitters are effective for in­depth analysis. The global curve fitter is the best solution for modes that are heavily coupled, have high damping, or have many antipodes. The SDOF, MDOF, and global curve fitters consider out­of­band residual effects to ensure maximum accuracy.

After you identify the location of modes and the type of curve fits, the STAR System automatically processes the entire measurement data set.

The STAR System synthesizes measurement results automatically after each curve fit to verify parameter estimates against the measured FRF.

After the STAR System identifies mode shapes, the Modal Assurance Criterion determines the correlation between the modes. This enables you to compare curve fits and determine the degree to which modes are coupled.

The Advanced Curve Fitter of the STAR System is a special hybrid algorithm that uses Least Squares Complex Exponential (LSCE) and polynomial techniques to accurately estimate modal parameters on complex or redundant data sets. You can evaluate single reference, multireference, or MIMO data for increased flexibility in working with unique data sets.

A graphical user interface makes these advanced techniques accessible even to occasional users. For example, informative graphics help you identify single and repeated mode locations. You can choose from multiple mode indicator functions and refer to detailed stability or S­plane diagrams.

The curve­fitting process is fast because the Advanced Curve Fitter accommodates extremely large model sizes, enabling you to evaluate wide frequency bands for modes and repeated roots.

The STAR System can conduct multireference analysis using most analyzers with two or more channels. You can use two­channel analyzers to collect multiple reference data, one reference at a time. Or, you can use a multichannel analyzer with a roving impact hammer to acquire multiple references at the same time. The STAR System uses the data from these tests to produce the best possible estimate of the modal parameters.

You can display animated mode shapes or operating deflection shapes individually, side­by­side, or superimposed.

To focus on the behavior of a particular area of your model, you can apply color to individual components or traces, isolate the component for viewing, or move the component away from the structure for highlighting. You can specify the direction of animation­x, y, and/or z axes-to study a specific aspect of the structure's motion.

Just as a video camera captures scenes for replay, time­domain animation replays events measured with sensors such as accelerometers. With this capability you can animate a geometric model using time history data measured from the structure' viewing motion that is too difficult or too complex for cameras to detect. Typical applications for time­domain animation include assessing structural response to shocks such as drop and impact tests, non­linear motion over long time periods, transient events, operating deflection shapes of running equipment, and machine run­ups and coast­downs.

The STAR System provides the smoothest time­domain animation in the industry. Because animation timing is critical, the animation algorithm optimizes itself for maximum accuracy on your computer. To better view the dynamics, you can use a special control panel to start and stop the animation and adjust variables such as speed.

The STAR System simplifies the building of structural models with its 3D mesh generator and interactive connectivity editor. You can define model manually, generate meshes, or graphically draw lines quickly and easily.

When some points on a structure are difficult to measure or are known to be the same as other measured points, you can take advantage of the STAR System's constraint equations. Constraint equations enable you to easily assign motion to any point not measured, providing more accurate and easy­to­understand structural animation.

Structural Modification and Simulation

• Add or remove masses from any points on the structure where the mode shapes are defined.
• Add springs and dampers between any two measurement points or DOFs.
• Connect measurement points on the structure to ground using springs or dampers.
• Add a tuned mass­spring­damper vibration absorber to defined points on the structure.SDM returns the modified modal properties of the structure with the attached absorber.
• Link a subsystem modeled with finite element techniques to an experimentally tested component. The result is composite structure from which you can compute the overall modal properties.

After making any modification, you can view its effect through animation or by synthesizing FRFs.

Reducing an objectionable vibration often requires shifting the structure's resonance from a particular frequency range. SDM lets you conduct sensitivity studies to determine where and how much modification is necessary. Using the Resonance Specification commands of SDM, you specify a desired structural resonance target and the type (mass, stiffness, or damping) and location of the modification. SDM then determines the amount of modification necessary to yield this result.

You can modify the model automatically using hardware modification commands, generating a complete set of new modal data that includes the specified resonance.

The best test of a proposed structural modification is to measure its response to realistic forcing functions. The Forced Response Simulation (FRS) feature of the STAR System delivers this crucial capability. You can use measured or synthesized power spectrum data of random, transient, sinusoidal, or user­defined excitation forces to determine displacement, velocity, or acceleration response at any point on the structure. You can input these forces at any number of points; the STAR System sums the response at the point of interest to generate realistic responses.

The sinusoidal simulation capability of the STAR System lets you compute the deformation shape that results from a combination of sinusoidal excitation forces applied at multiple points on the structure. You can observe the complete deformation shape with real time animation and evaluate the structure's response at any frequency in the measured range.

· STARBase™ provides a low­cost data collection and viewing station.

· STARView™ is designed to show you how a structure is actually moving.

· STARModal is the complete modal analysis solution. Options include:

· Advanced Curve Fitting

· Operating Deflection Shapes and Time­Domain Analysis

· Structural Dynamics Modification and Forced Response Simulation STARStruct™ is the complete structural dynamics analysis package.

Options and Add­ons You can easily tailor a system to meet the unique needs of your organization by combining options. Start with a basic system and add additional capabilities as you need them. Your STAR sales representatives can help you select the optimum configuration for your analysis and budget requirements.

Network Compatibility Networking licensing allows multiple users to access the full power of the STAR System from any computer on the network.

STARReport™ STARReport uses Windows OLE technology to produce digital reports which provide live mode shape animation, complete with viewing control, and interactive data plots in standard Windows­based word processors.

STARAcoustics™ STARAcoustics is a stand­alone STAR System product which uses acoustic intensity methods for noise source identification and sound power analysis. See the STARAcoustics brochure for more details.