The determination of the frequency transfer behavior of structures with non-linear characteristics is a task that occurs frequently in the technical field. For instance, it is important for the accurate determination of dynamic properties when designing new products or parametrizing models. The typical procedures used for the vibration measurement of such structures either rely on a linear structural behavior or require a lot of time and many measurements for the replication of the non-linear behavior. This often comes with high loads on the structure under test. Therefore, determining non-linear structural behavior is in many cases not efficiently realizable.

In his thesis, Dr.-Ing. Christian Sprock has developed a new approach for the vibration analysis of non-linear structures with a transfer behavior depending on the excitation amplitude. A focus was put on the determination of the non-linear behavior by measurements with significantly reduced effort and taking as little time as possible. The procedure is based on a measurement method, which allows an efficient determination of the non-linear characteristics of the structure under test using special multi-harmonic excitation signals. In combination with an advanced evaluation algorithm, a full description of the dynamic behavior can be generated in the form of a characteristic diagram.

The measurement procedure is supplemented by an identification routine, which can further reduce the required number of measurements. It is implemented as a measuring system in hardware and software. The functional verification was carried out using various examples.

The PhD thesis of Dr. Sprock is available here. His Publications are listed here.