Measuring equipment and contact persons
Although the Reseach Group SAM focuses mainly on fundamental research, it also conducts applied research in extensive test facilities that are made accessible due to the close cooperation with the Fraunhofer LBF.
For further information concerning this and an initial consultation, please contact Dr.-Ing. Christian Adams at Info.
Methods of experimental machine acoustics and system reliability
At the Research Group SAM, the common methods of experimental machine acoustics are used. This includes sound pressure recordings that are taken with microphones as well as the capturing of structure-borne sound with accelerometers or laser vibrometers. Furthermore, we can capture the sound intensity by means of so-called p-p sound intensity probes (3D), or directly with p-u sound intensity probes (1D). The capture of different signals can be used for the creation of noise maps, sound power determination, condition monitoring, or the measurement of the in structures. STI
We use systems that have up to 16 channels for the acquisition of measurement data. A variety of speakers, electrodynamic shakers of different power classes, and impulse hammers of different sizes are used as sources of excitation. For the investigation of active systems, we rely on Hardware-in-the-loop-systems.
Our laboratory offers adequate room for measurement investigations, where 2 different acoustic test rooms are available to us:
- Partially anechoic chamber (5.5 m x 4.5 m x 4 m) with a source room,
- Anechoic chamber (3 m x 2.2 m x 2.2 m).
Absorption coefficient measurement contact person: Info)
- Measurement of foam samples using 2-microphone methods as corresponding to the DIN 10534-2 standard “Determination of the sound absorption coefficient and impedance in a standing wave tube – part 2: methods with transfer function”
- Measuring range: 150 Hz – 1250 Hz
- Probe thickness maximum 190 mm
- Determination of modal values (natural frequencies, eigenvectors, modal damping) of structures of different sizes
- Evaluation of existing constructions, weak point analysis from a structural dynamic perspective, recommendations for possible design modifications
- Excitation by means of electrodynamic shakers or impact hammers of various sizes
Structure-borne sound measurement contact person: M.Sc. Clarissa Schaal)
- Acceleration measurement with uniaxial and tri-axial accelerometers
- Measurement of the surface velocity by means of (scanning-) laser vibrometers
Airborne sound measurement contact person: Dr.-Ing.. Christian Adams)
- Sound pressure level measurement by means of ½” and ¼” microphones
- Sound power measurement by means of the reference sound source method, reverberation room technique, and free-field method up to an accuracy class of 2
- Noise source identification by means of an acoustic camera (ring array, star array, and 3D array)
- Sound intensity measurement by means of a p-p sound intensity probe (3D) or a p-u sound intensity probe (1D)
- Creation of noise maps
- Consultation and execution of experimental investigations of functional relationships between the variability between the inputs and outputs of a system
- Adaptation of the experiment to existing resources and desired information
Methods of numerical machine acoustics and system reliability
At the Research Group SAM, common techniques of numerical analysis are also used. We offer the following benefits as services. A computational server and various software packages are available to carry out investigations.
Sound radiation contact person: M.Sc. Clarissa Schaal)
- Numerical calculation of the sound radiation of vibrating components by means of FEM or BEM
- Effects analysis of complex passive or active systems
- Investigation of the global functional relationship between the variability in the input and output variables of a system, e.g., for the optimization or robustness analysis of the system
- Analysis and evaluation of interactions between system components
- Application on nonlinear system behavior is also possible
- Calculation of sensitivity values for the characterization of the system parameters
- Determination of objective parameters to describe system behavior
Structural intensity contact person: M.Sc. Clarissa Schaal)
- Calculation of the structural intensity with a finite element analysis
- Analysis of the structural dynamic properties of a construction