In-Operando vibration analysis of technical systems with Laser Doppler Vibrometry

Dipl.-Ing. Xiaodong Cao

State of the art / motivation

• Single-point data acquisition for transient oscillations
• Full-Field data acquisition by 3D Scanning Laser Doppler Vibrometry for steady-state oscillations

Methods

• Additional local resolution via parallel techniques with Multi-Channel Vibrometer for transient oscillations
• Usable oscillation shapes up to 100 kHz from the use of laser excitation

Publications

1. X. Cao, C. Rembe:
   Non-Contact Damage Detection under Operational Conditions with Multipoint Laservibrometry.
   ^{In: sensors (Special Issue: Full-Field Optical Measurement Techniques for Damage Assessment). Vol. 20, Issue 3, 732, Jan. 2020.
   DOI: 10.3390/s20030732}
2. X. Cao, B. Tarigan, C. Rembe and H. Schwarze:
   Vibration-based white etching cracks detection at rolling contact bearings.
   ^{In: tm - Technisches Messen. Vol. 85, Issue 6, pp. 443-453, June 2018.
   DOI: 10.1515/teme-2017-0141}
3. X. Cao, B. Tarigan, H. Schwarze and C. Rembe:
   Damage Identification at rolling contact bearings.
   ^{In: tm - Technisches Messen. Vol. 84, Issue s1, pp. 34-41, Sept. 2017.
   DOI: 10.1515/teme-2017-0029}

Dipl.-Ing. Xiaodong Cao

State of the art / motivation

• Industrial Scanning Laser Doppler Vibrometer
• Robot-controlled 3D Scanning Laser Doppler Vibrometer

Methods

• Alternative solution by combination of a 1D Laser Doppler Vibrometer and an industrial robot
• Deployment of Multi-Channel Vibrometry

Research results

• 3D Scanning Vibrometer, realized with a single-point head and a robot, can be used flexibly for oscillations up to 23 kHz.
• Influence of specifically placed welding seams on oscillation power and attenuation can be measured with this Vibrometer Robot System.

Publications

1. X. Cao, R. Schmelter, T. Ziemer, A. Lohrengel and C. Rembe:
   Analyse von Plattenschwingungen mit einem robotergesteuerten 1D Vibrometer zur Charakterisierung des Einflusses lokaler Materialinhomogenitäten.
   ^{In: Fakultät für Mathematik/Informatik und Maschinenbau, Technische Universität Clausthal (Hrsg.): Technical Report Series. Fac3-16-02. Oct. 2016.}

Dipl.-Ing. Xiaodong Cao

State of the art / motivation

• Method of characterizing structure-borne sound for SDOF- and MDOF-coupled systems
• Lack of a method for areal-coupled systems

Research activity

• Mapping of the system with finite element model and adjustment of the model parameters with model updating procedures using the measurement data from the full field vibration measurement
• Calculation of the structure-borne sound transmission in the system using the adjusted model
• Optimization of the structure-borne sound properties of the system using the FE model

Research results

• Structure-borne sound energy flow on structures joined by bolted connections must be simulated with high resolution using FEM models.
• FEM models must be adapted to the physical reality via model updating procedures in order to determine the energy flow correctly.

Publications

1. X. Cao, S. Backhaus, R. Scheidl and C. Rembe:
   Numerical and Experimental Analysis of structure-borne Sound Transmission in Coupled Systems.
   ^{In: Proceedings of the 12th Int. Conference on Vibration Measurements by Laser and Noncontact Techniques, Ancona, Italy, 2016.
   DOI: 10.1063/1.4952681 .}