New Frequency Domain Operating Deflection Shapes Task

In ARTeMIS Modal 6.0, we have updated frequency domain Operating Deflection Shapes task. The shapes are now estimated using Phased Assigned Spectra’s allowing read-out of Peak, Peak-to-Peak, RMS and Power values at all measured DOF’s. User is free to select units and measurement type (displacements, velocities, accelerations). Please have a look at the video at www.svibs.com/ODS.

New Instruction Videos for Multi-Setup OMA Testing

We have now added a series of videos showing how to perform multi-setup testing using ARTeMIS Modal. Please have a look at the videos at www.svibs.com/HowTo.

Next ARTeMIS User Training Course

The next annual user training course will take place in Aalborg, Denmark on October 29-30, 2019.

This 2-day course is for the new as well as experienced users that would like to be updated on Operational Modal Analysis and Experimental Modal Analysis as well as the latest features of ARTeMIS Modal software.

The course will be held at Comwell Hotel Hvide Hus in Aalborg, Denmark. Both days we start at 9.00 and end at 17.00. There will be lunch and coffee breaks during the day and free WiFi internet access. The course instructor is Dr. Palle Andersen, CEO at Structural Vibration Solutions A/S.

More information is available at www.svibs.com/News.

Operational Modal Analysis Course

– Similarities and Differences to Classical Modal Analysis

September 30 – October 1, 2019, Ingolstadt, Germany.

This 2-day course will give a general insight to the theory and practice of Experimental Modal Analysis. The similarities and differences between Operational Modal Analysis and Classical Modal Analysis will be the main focus. There will be practical demonstrations and hands-on exercises during the course. The social event is a visit to the Munich Octoberfest.

More information is available at www.svibs.com/News.

ARTeMIS Modal 6.0 Released

ARTeMIS Modal 6.0 has now been released and includes many new features and enhancements. Existing users should log in at www.svibs.com and download the latest build 6.0.0.2. If you are not already a user and wish to try it out, please go to the Download section to get a 30 days trial version.

New features and layout

ARTeMIS Modal 6.0 has many new exciting features. Some of these are

1. Mode shape uncertainty estimation (SSI-UPCX only).
2. Modal Alignment window for all estimators driven by a stabilization diagram.
3. Automatic Mode Estimation in Frequency Domain Decomposition methods has been improved, and can now also be operated using a graphical slider for the MAC Rejection level.
4. Data Acquisition plugins combined with EMA plugin enable impact testing directly in ARTeMIS Modal.
5. Software platform now supports both Tabbed and SDI layouts.
6. Multiple animations can now be exported automatically in AVI and GIF formats.

Please have a look at this YouTube video that introduces some of these new features:

Figure 1: ARTeMIS Modal 6.0 – New features and layout.

Special ARTeMIS Bundle Offers – Valid until 31 March, 2019

If you are interested in Experimental Modal Analysis (EMA), with or without Direct Hardware Control, we are running a special limited offer, on all versions of ARTeMIS Modal.

Buying a license of any version of ARTeMIS Modal bundled with the EMA plugin and optionally a Direct Hardware Control plugin, can be done at a very affordable bundle price.

Please contact sales@svibs.com for more information or a quotation.

See you at IMAC-XXXVII and IOMAC-2019

We will be demonstrating all the new exciting features of ARTeMIS Modal 6.0 at the International Modal Analysis Conference (IMAC) in Orlando, Florida on January 28-31, in booth #213. We are also present at the International Operational Modal Analysis Conference (IOMAC) in Copenhagen, Denmark on May 13-15, 2019.

Next User Training Course

The next user training course will take place in Aalborg, Denmark on October 29-30, 2019.

This 2-day course is for the new as well as experienced users that would like to be updated on Operational Modal Analysis and Experimental Modal Analysis as well as the latest features of ARTeMIS Modal software.

The course will be held at Comwell Hotel Hvide Hus in Aalborg, Denmark. Both days we start at 9.00 and end at 17.00. There will be lunch and coffee breaks during the day and free WiFi internet access. The course instructor is Dr. Palle Andersen, CEO at Structural Vibration Solutions A/S.

Upcoming New Module – Experimental Modal Analysis

In ARTeMIS Modal 6.0, planned for a release in the second quarter of 2018, we are introducing a new module for Experimental Modal Analysis (EMA). The new module will support both hammer and shaker tests that deploy Frequency Response Functions (FRFs) obtained in one of the following ways:

1. Direct uploading of the FRF’s from Universal File Format. In this case, some of ARTeMIS Modal tasks are either hidden or simplified. This also count for the Prepare Data Task as there is no signal processing to do.
2. Upload of simultaneously measured input and output time histories into the Manage Measurement Task, then followed by the estimation of the FRF’s using either H1, H2 or Hv estimators. This is accomplished in the Prepare Data Task.
3. Use the ARTeMIS Modal data acquisition plugins to measure input and output simultaneously then followed by the estimation of the FRF’s using either H1, H2 or Hv estimators as in (2).

Below a preview of this new module can be seen.

Experimental Modal Analysis of an Audi TT Car Body

The experimental tests presented here has been conducted at TH Ingolstadt, Faculty of Mechanical Engineering, Germany under the guidance of Professor J. Bienert, who is gratefully acknowledged.

The experimental campaign consist of impact (hammer) testing of an Audi TT car body, see a picture depicted below.

The car body was mounted free on four air cushions. Four references respectively impact points were excited with 14 accelerometers as responses. The data acquisition and processing of the FRF’s were made with a 24-channel data acquisition system. The FRF’s were stored in the four separate Universal File Format Files (Audi_TT_FRF_runX.unv) along with a test geometry in its own file (Audi_TT.unv).

Importing FRF’s into ARTeMIS Modal

Importing the FRF’s into ARTeMIS Modal starts with creating a new project using Universal File Format, which is illustrated in the picture below.

Once the files are uploaded, the geometry and FRF’s can be seen in the simplified Prepare Data task. The Data Organizer contains all four impact tests listed below each other, and the Geometry window visualize the positions and the directions of the response and reference channels. All the impact positions can be viewed by selecting the first item, All Test Setup, in the Data Organizer, illustrated below.

The 14 response accelerometers are seen in blue, and the impact positions, indicated by a hammer symbol, are colored green.

Estimating Modes using Rational Fraction Polynomial – Z Domain

The modal parameters of the car body are computed with a Rational Fraction Polynomial estimator working in Z-domain. This estimator has been developed in cooperation with Politecnico di Torino, Dynamics and Identification Research Group (DIRG) at Department of Mechanical and Aerospace Engineering, Italy, the I4S Team at Inria, France and Aalborg University, Department of Civil Engineering, Denmark.

The estimator has been adapted, so it is operated in nearly the same way as the Stochastic Subspace Identification methods used for Operational Modal Analysis in ARTeMIS Modal.

The work flow is as follows:

1. Select a maximum model order to initialize the estimation of the system matrices of the highest dimension for the subsequent computation of a lower model orders.
2. Select the desired frequency band.
3. Select a specific range of the model orders by dragging the mouse down on the stabilization diagram, or simply click the Estimate Models button to estimate all the model orders.
4. Stable modes are found by a study of the natural frequencies, damping ratios and mode shapes (MAC and maximum modal complexity).
5. Global modes are estimated based on the stable modes.

The figure below illustrates the analysis of the experimental test of the Audi TT in the frequency range from around 4 Hz up to 140 Hz. Maximum model order was set to 80, however only models up to 60 were estimated.

Validating Modes with Other Estimators

The modes obtained from the RFP-Z estimator are validated using the standard tools available in ARTeMIS Modal. By selecting the Validation Task, the modes can be compared with the other estimators as well as imported results from any other modal analysis tools. Below we are comparing the RFP-Z modes with the modes obtained with a simple peak-picking tool already available in ARTeMIS Modal. It is based on the peak picking on the Complex Mode Indicator Function (CMIF).

International Seminar on Modal Analysis Conference (ISMA 2018)

We will be presenting the new RFP-Z estimator and Impact Testing Module at ISMA conference on September 17-19, 2018 in Leuven, Belgium. See you in booth 14!

Next User Training Course

The next user training course will take place in Aalborg, Denmark on November 6-7, 2018.

This 2-day course is for the new as well as experienced users that would like to be updated on Operational Modal Analysis and Experimental Modal Analysis as well as the latest features of ARTeMIS Modal software.

Venue

The course will be held on November 6-7, 2018 at Comwell Hotel Hvide Hus in Aalborg, Denmark. Both days we start at 9.00 and end at 17.00. There will be lunch and coffee breaks during the day and free WiFi internet access. The course instructors are Dr. Palle Andersen, CEO at Structural Vibration Solutions A/S and Mr. Ilija Trenchevski, senior developer of ARTeMIS Modal at Structural Vibration Solutions A/S.

Programme

On day 1, you will get a comprehensive introduction to Experimental Modal Analysis (EMA) and Operational Modal Analysis (OMA) in general. During this introduction, the differences and similarities between EMA and OMA will be described. Also the procedures for acquiring high quality measurements will be discussed in details. We will help each other acquiring good measurements of different demo structures both for EMA and OMA applications. The introduction is followed by a presentation of the user-friendly Frequency Domain Decomposition (FDD) technique, and we will analyze the acquired measurements as hands-on exercises. Finally, the two other FDD related techniques of ARTeMIS (Enhanced Frequency Domain Decomposition and Curve-fit Frequency Domain Decomposition) are introduced, and we will continue with hands-on exercises using these techniques. The technical programme will end with the analysis of the acquired EMA data using the Complex Mode Indicator Function – Peak Picking method (CMIF).

We end day 1 at a restaurant in the old downtown of Aalborg.

On day 2, you will be introduced to the advanced OMA methods called Stochastic Subspace Identification (SSI) as well as the parametric EMA method called Rational Fraction Polynomial in Z-domain (RFP-Z) and the latest features available in ARTeMIS such as the Structural Health Monitoring plugins.

You will get course material as well as a 1-month free demo version of the ARTeMIS Modal Pro which we invite you to install on your own laptop for use during the hands-on exercises of the course.

Price

Attending the course will cost 950 EUR per person. Students get 50% discount. Book before August 31, 2018 and SAVE 10%!

Prices includes 25% Danish VAT (moms).

Sign Up

Please download the registration form and send it by email to Structural Vibration Solutions at mo@svibs.com. We need your registration no later than October 1, 2018.