Crack localization verification of effective Structural Health Monitoring system using flow simulations

Scriptie/Masterproef: Master's Thesis

Samenvatting

According to the general growing interest in Structural Health Monitoring systems, the Vrije Universiteit Brussel developed a new crack localization technique based on the embedding of pressurized capillaries in structures and using the propagation of acoustic pressure waves through them. The present thesis addresses the verification of this technique by analyzing and understanding the physical phenomena that describes the entering flow and the filling of the capillary when a crack reaches it. This analysis is achieved with the use of flow simulations performed with different Computational Fluid Dynamics programs. For the understanding of the simulation results, an extended literature study is realised in order to associate existing theoretical models
with the observed physical phenomena. The Shock Tube Model and Shock-Boundary Layer Interaction Model are examples of relevant models. Several simulation configurations are presented in order to highlight the difference between experiments during which the crack was simulated and the reality. The presence of shock waves is discovered and their propagation through the capillary investigated and detailed. These waves complicates the previously proposed localization technique since their propagation speed depends on their intensity, in contrast to the acoustic pressure waves. The importance of this negative implication and some possible solutions are discussed. It indicates that the reduction of the friction by passing to micro-channels appears to be a plausible option. Other methods such as wall cooling, boundary layer suction/blowing and reduction of the capillary roughness are also cited but would need further investigations.
Datum prijs2018
Originele taalEnglish
BegeleiderPatrick Guillaume (Promotor)

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