Bond-slip characteristics of slightly corroded (less than 2% mass loss) reinforcing steel bars embedded in concrete were investigated with pull-out tests conducted after exposure to high temperature and subsequent cooling. Twenty-five scenarios consisting of five corrosion levels (0.0%, 0.5%, 1.0%, 1.5%, and 2.0% corrosion loss) and five exposed temperatures (20°C, 200°C, 400°C, 600°C, and 800°C) were tested. The results indicate that the slight corrosion of the reinforcement not only affects the bond performance of concrete and steel bars but also influences their reaction to elevated temperature before the exposure temperature exceeds 400°C. The effect of slight corrosion on bond-mechanics behavior was eliminated by the dramatic decrease in concrete strength and significantly different thermal expansion between concrete and steel as the exposure temperature reached 600°C.

In this study, systematic numerical simulations are conducted to investigate how swirl ratio and radial Reynolds number affect the wind characteristics of multi-vortex tornadoes. By properly controlling boundary conditions, multi-vortex tornadoes are produced in a cylindrical computational domain. Six cases with different swirl ratios are studied to examine the influence of swirl ratio, while five cases with different radial Reynolds number are studied to investigate the influence of radial Reynolds number. To facilitate the characterization, the core size and rotational speed of subvortices, as well as the relative distance between the subvortex and the core radius of the main vortex, are defined. The results demonstrate that the increase in swirl ratio leads to the increase in the number of subvortices. For the overall vortex, the increase in swirl ratio decreases the maximum tangential velocity but increases the core radius of the overall flow. For subvortices, for the case where four subvortices are produced, the increase in swirl ratio increases the core size of subvortices but decreases the rotational speed of subvortices. While the increase in radial Reynolds number does not change the number of subvortices produced, it decreases the core size of subvortices, but increases the rotational speed of each subvortex.

While understanding breaking waves is crucial for the development of parametrizations used in ocean wave modeling for both deep and shallow water, the complete process of wave breaking is not well understood. Here we present direct numerical simulations of two-dimensional solitary waves that shoal and break on a uniform beach in shallow water, with the presence of storm surge represented by an inshore region. The storm surge depth, beach slope, and wave amplitude are varied to study the dependence of energy dissipation in the breaker on wave and bathymetric parameters. We classify wave breaker types and find a separation between plunging and spilling breakers when scaled by breaking amplitude and depth. We compare energy dissipation during the breaking process with results from the literature without storm surge. A representation of energy dissipation in this solitary wave breaker data is also compared with prior experiments and simulations of breakers in deep water, and possibilities of a unifying model are explored. We conclude that a previously developed shallow-water inertial dissipation model for wave breaking on a uniform slope can be extended to this storm surge environment with good data collapse, and we further discuss possibilities for a general parametrization of wave breaking valid across different depth regimes.

In the study, a series of wind tunnel tests were conducted to investigate wind effects acting on dome structures (1/60 scale) induced by straight-line winds at a Reynolds number in the order of 10⁶. Computational Fluid Dynamics (CFD) simulations were performed as well, including a Large Eddy Simulation (LES) and Reynolds-Averaged Navier–Stokes (RANS) simulation, and their performances were validated by a comparison with the wind tunnel testing data. It is concluded that wind loads generally increase with upstream wind velocities, and they are reduced over suburban terrain due to ground friction. The maximum positive pressure normally occurs near the base of the dome on the windward side caused by the stagnation area and divergence of streamlines. The minimum suction pressure occurs at the apex of the dome because of the blockage of the dome and convergence of streamlines. Suction force is the most significant among all wind loads, and special attention should be paid to the roof design for proper wind resistance. Numerical simulations also indicate that LES results match better with the wind tunnel testing in terms of the distribution pattern of the mean pressure coefficient on the dome surface and total suction force. The mean and root-mean-square errors of the meridian pressure coefficient associated with the LES are about 60% less than those associated with RANS results, and the error of suction force is about 40–70% less. Moreover, the LES is more accurate in predicting the location of boundary layer separation and reproducing the complex flow field behind the dome, and is superior in simulating vortex structures around the dome to further understand the unsteadiness and dynamics in the flow field.