Mechanical heart valve replacement is the preferred alternative in younger patients with severe symptomatic aortic valve disease. However, thrombus and pannus formations are common complications associated with bileaflet mechanical heart valves. This leads to risks of valve leaflet dysfunction, a life‐threatening event. In this experimental study, we investigate, using time‐resolved planar particle image velocimetry, the flow characteristics in the ascending aorta in the presence of a dysfunctional bileaflet mechanical heart valve. Several configurations of leaflet dysfunction are investigated and the induced flow disturbances in terms of velocity fields, viscous energy dissipation, wall shear stress, and accumulation of viscous shear stresses are evaluated. We also explore the ability of a new set of parameters, solely based on the analysis of the normalized axial velocity profiles in the ascending aorta, to detect bileaflet mechanical heart valve dysfunction and differentiate between the different configurations tested in this study. Our results show that a bileaflet mechanical heart valve dysfunction leads to a complex spectrum of flow disturbances with each flow characteristic evaluated having its own worst case scenario in terms of dysfunction configuration. We also show that the suggested approach based on the analysis of the normalized axial velocity profiles in the ascending aorta has the potential to clearly discriminate not only between normal and dysfunctional bilealfet heart valves but also between the different leaflet dysfunction configurations. This approach could be easily implemented using phase‐contrast MRI to follow up patients with bileaflet mechanical heart valves.

This study proposes a resilience-based design approach that considers the correlation between the resilience response of self-centering post-tensioned (SCPT) steel beam to column connections and the inelastic performance of the required energy dissipation (ED) system. A compact circular hollow steel tube (CHST) is proposed as a replaceable ED system. On the basis of existing experimental results, a detailed three-dimensional finite element modeling (3D-FEM) was carried out to identify the response of the compact CHST under half cyclic loading. A large number of numerical works ended with the extraction of design charts to determine the axial strain (ΔL/L) of the ED system before encountering post-yield buckling and/or excessive strength degradation. Accordingly, in a numerical validated reference SCPT connection, several predesigned ED systems were implemented for simulation. As a result, according to the design charts, the optimum selection of proper inherent depth to thickness (D/t) ratio and length to depth (L/D) ratio of the CHST-ED system can increase the resilience of modern self-centering steel structures. In addition, the improvement of the entire connection resilience is associated with the development of satisfactory energy dissipation capacity. Furthermore, the superior performance of the connection under sequential cyclic loading promotes the application of the proposed SCPT-ED connection in a resilient structural system.