PSI - Issue 57

Ewelina Czerlunczakiewicz et al. / Procedia Structural Integrity 57 (2024) 743–753 / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 4. Calculation methods scheme

2.4. Non linear behavior As previously mentioned, the mathematical modeling of clipping connections (Fig. 5)is necessary for their implementation in FEA. In linear simulations, a simplified and linear approach was used to model these connections. However, in the non-linear analysis, a non-linear representation was employed for the chosen junctions. This non linear definition allowed for a different behavior of the connection compared to the linear bonded assumption. The stiffness and damping of the junction are defined, and the connection is permitted to transition between contact and no-contact states. This means that the non-linear analysis takes into account the possibility of intermediate contact states, allowing for a more realistic representation of the behavior of the clipping connections. That allowed the presence of small shocks. On the other hand, in the linear analysis, only one contact or no-contact condition can be considered at a time during a single analysis.

gap

Fig. 5 Clipping connection

2.5.

Excitation

In all simulations, a random load signal is considered as vibration load applied to the ECM. The mono-axial PSD comes from an accelerated vibration signal commonly used by automotive OEM for the design validation of chassis mounted components. Its duration is 30 hours per axis, 1.5 gRMS and a frequency range between 5 and 50 Hz. However, it's important to note that for simulation purposes, only a short time series sequence is used in the time domain analysis.The duration and samplingrate of the signal were selected in a way that ensures statistically reliable fatigue damage calculation and excitation profile representativeness. Importantly, all the time series methods rely on