The utilization of novel engineering materials like shape memory alloys has significantly broadened their application scope within civil engineering. Consequently, this study examines the mechanical performance of a grooved metallic-yielding damper fabricated from shape memory alloys. The seismic performance of the new system has been studied using the nonlinear static analysis method in ABAQUS software. Also, after a parametric investigation, the applicability of this kind of damper in a steel frame has been evaluated using the nonlinear dynamic analysis and considering the accelerograms of near-fault and far-fault earthquakes. The superelastic behavior of shape memory alloys has been applied to ABAQUS software by using the Brinson model and considering phase transformations. Lastly, the effect of various geometric parameters on the steel frame’s seismic performance, including stiffness, ductility, and energy absorption capability, has been studied. The results indicate that the ductility of the presented new damper is 56 and is greater than ductility of many conventional metal damper. Also, studied damper has great energy absorption and can easily replace other metallic-yielding dampers including ADAS and TADAS. Moreover, it is evident that the proposed system exhibits substantially enhanced energy absorption and ductility equated to the braced frame equipped with the equivalent steel damper, thus rendering it suitable for engineering applications.

This study investigated the influence of changes in the tool shoulder diameter on the microstructure, bonding, diffusion, and tensile-shear behaviors of the dieless friction stir rivetted CP-copper/Zn/AISI 321 stainless steel joints. The results reveal that the increase in the shoulder diameter increases the peak temperature, width of the brazed and stir zones, and the tensile-shear load (1944-2429 N) of the joints. The wider tool shoulder produced a good metallurgical/interfacial bonding at the stir zone and restrained upper sheet bulging (USB) effect at the brazed zone of the joint whereas USB-induced sheet separation and lateral unbonded path could not be prevented with the smaller tool shoulder diameter (12 mm). The change of the tool shoulder diameter changes the fracture behavior and the diffusion gradients of Cu from steep to gradual profile due to differences in the friction-induced heat input/temperature. A wider tool shoulder diameter is recommended for defect elimination and improved strength.

Torpedo anchor is a kind of deep-sea anchorage structure with the advantages of simple installation, low cost, and broad application prospects. Its bearing capacity is closely related to the stability and anti-wind ability of the mooring structure. Based on the Abaqus software, the pull-out bearing characteristics of torpedo anchors were simulated, and the influence of pull-out angle, soil properties, buried depth, and length-diameter ratio on the bearing capacity were analyzed. The results showed that with the increase in pull-out angle, the bearing capacity increased first and then decreased. When the pull-out angle reached 45°, the bearing capacity reaches the maximum, while the bearing capacity reaches the minimum when the pull-out angle attained 90°. The uplift capacity of the torpedo anchor increased with increasing undrained strength and buried depth. When the buried depth keeps constant, the bearing capacity increased with the increase of length to diameter ratio.

Current study was conducted on the evaluation of corrosion resistance of reinforced concrete containing ordinary Portland cement (OPC) blended with wheat ash (WA) and wheat stalk ash (BFS) as mineral admixtures under simulated marine conditions using electrochemical techniques. WA and BFS admixtures were used to partially replace the OPC including OPC0 as control sample (400 kg/m3 OPC), OPC+BFS60 (340 kg/m3 OPC+60 kg/m3 BFS), OPC+WA60 (340 kg/m3 OPC + 60 kg/m3 WA) and OPC+WA30+BFS30 (340 kg/m3 OPC+30 kg/m3 WA + 30 kg/m3 BFS). Results of potentiodynamic polarization, cyclic voltammetry and electrochemical impedance spectroscopy analyses indicated that OPC+WA30+BFS30 sample showed higher corrosion resistance and potential than the other samples because of the synergetic effect BFS and WA in concrete which enhanced the steel rebar corrosion resistance in 3.5 wt% NaCl solution. Moreover, the SEM studies showed that the OPC+WA30+BFS30 had lower corrosion products and lower density of narrow pits on steel surface than that OPC0 specimen which confirmed the electrochemical studies. These results demonstrated that WA and BFS can used as appropriate mineral admixtures to decrease hydroxide ion concentrations and enhance the passivation of the reinforcement steel rebar in marine environments.

Under the loading of earthquake, sandy soil is prone to liquefaction and resulting in the superstructure damage. Therefore, the liquefaction identification of sandy soil is the primary task of liquefaction disaster prevention. Based on the energy dissipation method, the relationship between pore water pressure (u) and dissipated energy density ( W ) of fiber-reinforced sand (FRS) is established, and the effects of fiber length ( FL ), fiber content ( FC ), cyclic stress ratio ( CSR ), and relative density ( Dr ) on the accumulation of u are analyzed. The results showed that fiber addition can effectively slow down the liquefaction of FRS, and the curve of u and W can be divided into rapid growth stage, stable ascend stage and slow growth stage. When the u keep constant, the W increases with the increasing of FL and FC . Whereas, the u decreases with the increasing of FL and FC when the W keep constant. The u and W are less affect by CSR , and the dense sand of FRS is less prone to liquefaction than loose sand.

This paper mainly studies the influence of clinker mineral composition on the performance (flow variability and expansion performance, hole structure, etc.) of silicate cement. The experimental results show that the shear stress of silicate cement slurry body consisting of different minerals is different with the rheography curve of shear rate, and the linear relationship between the two belongs to Bingham rhesino equation, the expansion rate is also quite different, the expansion rate of D mineral composition is the largest, and the distribution of the aperture of different minerals composition is different, the size of the gap and the degree of hydracy are different.