Atwater Village Cable-Stayed Equestrian Bridge

<p>This will be the second cable-stayed bridge in the city of Los Angeles. In order to mitigate the potential for resonant vibrations during passage of groups of equestrians, a system of tuned mass dampers was designed for the bridge. High-stressed cables are incrementally attached to the 38-meter-tall mast and configured in a fan pattern.</p>

Development of models of vibrations of critical structures and regulatory approaches to calculations for seismic impacts

The calculation of the stability of the equilibrium position required by the canceled and current norms of earthquake-resistant construction, and the calculation of the dynamic stability of various partial movements, the requirements for the necessity of which are absent both in the proposals for the norms of the new generation and in the current norms of earthquake-resistant construction, are the main ones in the calculation and design of structures taking into account their interaction with the base. Special and emergency seismic loads are identified that create an emergency situation − the occurrence of a mode of beating or resonant vibrations, as well as parametric resonance and nonlinear vibrations that occur after the loss of stability of the position of structures.

Assessment of the Impact of Shot Peening on the Fatigue Life of a Compressor Blade Subjected to Resonance Vibrations

The publication presents the assessment of the influence of surface treatment such as shot-peening on the fatigue life of a compressor blade exposed to resonant vibrations. As part of the work, a geometric model of the blade was developed and a numerical modal and fatigue analysis were performed. The fatigue analysis was based on the Manson-Coffin-Basquin and Ramberg-Osgood models. As part of the work, the influence of different values of residual stresses on the results of fatigue life was determined. Additionally, the location of the highest equivalent stresses was established. The obtained results of the numerical analyzes were compared with the results presented in the scientific literature. An additional aim of the study was to determine the size of the grains at various points of the blade as well as the thickness of the layer plasticized as a result of peening. The obtained results are presented in the form of tables and charts. The relationship between the location of the highest values of equivalent stresses and the thickness of the plasticized layer was determined. The explanation of the effect of shot peening on the increase in fatigue life of the blade was proposed.