Challenges of coupling effective masses and shaker models for virtual shaker testing

In spacecraft engineering, environmental testing is crucial to demonstrate the spacecraft’s integrity against dynamical launch environments. Vibration environmental testing is performed with state-of-art shakers testing facilities, where, usually, the testing facility couples with that of the test specimen. This can lead to unexpected challenges, e.g., beating phenomena, over- or under testing, and even damage. A way to tackle this problem is to simulate the test in a safe virtual environment taking into account the coupling between the shaker and the article. Traditionally, the coupled models are obtained by combining finite element models or retrieved from experimental data. Practically, challenges may arise from both approaches linked to the clearance necessary to share the FE models or the need of having test fully instrumented. In this paper an alternative is investigated that relies on the coupling between an effective mass model of the article and a lumped parameter model of the shaker. The effective masses have no evident physical meaning and can be shared without confidentiality disputes. On the other hand, the shaker parameter can be obtained experimentally on the empty shaker without the need of a fully instrumented test. In this paper the steps of the procedure are briefly explained together with the comparison between the predicted numerical test results and the experimental data.