Explore the vast range of titles available.

This article experimentally examines the crashing performance and failure mechanisms of jute fiber ( J )-reinforced epoxy/aluminum (Al) hybrid pipes with circular cutout. Wet wrapping by hand lay-up was used to manufacture the designed hybrid pipes, and they were tested under quasi-static axial loads. As crash indicators, hybrid pipes' initial peak load ( F ip ), total absorbed energy (AE), mean crash load ( F m ), specific energy absorption (SEA), and crash force efficiency (CFE) were evaluated. On these indicators, the effect of the number J-plies ( P ) and circular cutout parameters, i.e., diameter ( D ) and number ( N ) of holes, was evaluated. To make statistical predictions about the crash indicators, mathematical regression equations were used. Furthermore, the variance of analysis (ANOVA) was also adapted to determine the percent contribution of each parameter to crash indicators. The experimental outcomes revealed a significant relationship between the studied parameters and the crashing performance as well as the failure mechanisms. Results showed that D is the maximum impelling parameter on the values of F ip and AE with contribution percents of 50.73 and 62.18%, respectively, followed by P with contribution percents of 37.76 and 27.91%, respectively. While P is the highest influencing parameter on the values of F m , SEA, and CFE with contribution percents, respectively of 59.87, 45.77, and 61.98%, followed by D for F m and SEA with contribution percents of 34.66 and 34.83% but N for CFE with a percent of 27.05%.

This study examines how the infill configuration and density can affect the crashworthiness and crash history of 3D-printed configurations exposed to quasi-static axial loading. Polylactic acid (PLA) was used to create the planned structures through a 3D printing process. With 30, 50, and 70% infill density, three infill configurations, i.e., circular, square, and triangle, were prepared. Different crash indicators, containing initial peak force ( F ip ) , overall absorbed energy (U), mean crashing load ( F m ) , crash force efficiency (CFE), and specific energy absorption (SEA), were evaluated, as well as the crash history of the designed pipes. Results indicated that both the infill configuration and density have substantial impacts on the crashworthiness of 3D-printed structures. Therefore, the S70 pipe shows the maximum F ip , U , F m , and SEA with values of 33.52 kN, 1095.08 J, 30.42 kN, and 31.10 J/g, respectively. Whereas the maximum CFE was recorded for C70 pipe with a value of 1.16.

Hydraulic oscillator is an important drilling equipment extensively used in petroleum extraction and drilling work. It generates vibration along the axis direction to drive the drilling tool to drill and the drilling effect largely depends on the axial impulsive loading and frequency of the hydraulic oscillator. However, few present studies have been conducted on the influence of variations in key geometric parameters on axial impulsive loading and frequency of hydraulic oscillators, and systematic analysis is still lacking. Optimization calculations were carried out on throat inner diameter, throat length, nozzle spacing, and nozzle angle of the hydraulic oscillator. The analysis results show that: The overall impact of throat length and nozzle angle changes on axial load is small, while throat inner diameter has the greatest impact on the axial load. The axial load is 375.78 N when throat inner diameter is 10 mm, which is 8 times larger than that when throat inner diameter is 20 mm. Moreover, the throat inner diameter is smaller, both the axial load and amplitude are greater. Nozzle spacing has a significant influence on the axial load within a narrow spacing range. As nozzle spacing increases, the axial load increases overall while the amplitude shows a decreasing trend. Particularly, when nozzle spacing exceeds a certain value, the axial load does not vary significantly.

To explore the failure modes of high-Ni batteries under different axial loads, quasi-static compression and dynamic impact tests were carried out. The characteristics of voltage, load, and temperature of a battery cell with different states of charge (SOCs) were investigated in quasi-static tests. The mechanical response and safety performance of lithium-ion batteries subjected to axial shock wave impact load were also investigated by using a split Hopkinson pressure bar (SHPB) system. Different failure modes of the battery were identified. Under quasi-static axial compression, the intensity of thermal runaway becomes more severe with the increase in SOC and loading speed, and the time for lithium-ion batteries to reach complete failure decreases with the increase in SOC. In comparison, under dynamic SHPB experiments, an internal short circuit occurred after impact, but no violent thermal runaway was observed.

This paper investigates the effectiveness of engineering cementitious composites (ECC) thin layers for seismic strengthening of reinforced concrete (RC) short walls with high axial load ratios. Three RC short walls with an aspect ratio of 1.1 were tested under cyclic loading: one control wall and two ECC strengthened walls, adopting two different strengthening layer schemes. The results showed that the failure mode, damage tolerance, lateral stiffness, shear strength, and energy dissipation of the strengthened walls were improved to certain extents. The mesh grid ECC layer was proved an effective and applicable technique, the shear strength and energy dissipation of the corresponding strengthened wall were improved by 37.2% and 33.5%, respectively, and the addition of mesh grid and tie bars in the ECC layer prevented the debonding failure at the ECC/concrete interface. Besides, the shear resistance mechanisms of the test specimens were idealized by the strut-and-tie model, the contribution of cracked ECC tensile strength to shear was considered in the horizontal and vertical mechanisms. The predicted shear strengths of the RC walls agreed well with the test values.

In the last three decades, glass fiber-reinforced polymer (GFRP) has gained wide acceptance as an alternative reinforcement to avoid the potential of corrosion and related deterioration of reinforced concrete infrastructure. Recent experimental results for concrete columns reinforced entirely with GFRP bars have demonstrated their effectiveness in resisting lateral loads induced by wind or earthquakes. However, in most of the research studies carried out so far, the columns were tested under reversed cyclic loading, while subjected to low to moderate levels of axial load that would be rather representative of columns located in the top stories of multi-story buildings. This has been the main impetus to investigate FRP-reinforced columns under high levels of axial load with different ratios of longitudinal reinforcement. To that end, a finite element model (FEM) that considers the material and geometric nonlinearity and the bond behavior of GFRP bars was developed and validated against the available experimental results. Twenty-one specimens encompassing wide levels of axial load and longitudinal reinforcement ratios were studied. Results are presented in terms of strength, stiffness, and deformation capacity as affected by axial load. The moment-axial load interaction diagrams for the simulated specimens are also discussed. The paper concludes by proposing the most appropriate performance design levels for GFRP-reinforced columns. Quantification of the seismic response parameters within this study is aimed at facilitating the adoption of GFRP bars in North American codes as internal reinforcement for earthquake-resisting systems. Keywords: axial load; columns; finite element analysis; glass fiber-reinforced polymer (GFRP) bars; moment-axial load interaction; performance levels; reinforced concrete; residual damage; seismic behavior.

This study aims to analyze the structural performance of castellated steel columns under axial load and seismic displacements, focusing on the effect of different strengthening techniques on load-bearing capacity and ductility. The purpose of this study is to determine the best method for strengthening these columns to improve their seismic response and reduce the risk of collapse. To achieve this, four specimens were analyzed: non-strengthened column, a horizontally strengthened column, a vertically strengthened column, and a column strengthened with horizontal and vertical plates. All specimens were subjected to a static axial load test of 40 kN, while lateral displacement was modelled using seismic data from a real event. The results showed that vertical strengthening was the most effective in enhancing load-bearing capacity and improving seismic response. Maximum lateral loads increased by 63% in the vertically strengthened columns, 55% in the vertically and horizontally strengthened columns, and only 13% in the horizontally strengthened columns. This strengthening also reduced stress concentrations around the hexagonal openings, helping prevent collapse in those areas. Vertical strengthening represents the optimal solution for improving the seismic performance of castellated steel columns, providing an effective balance between load resistance and improved structural stability. Accordingly, the study recommends further research to develop more efficient strengthened techniques that enhance the resistance of steel columns in seismic applications.

The total force produced in the axial direction on a pump is called axial load and is caused by the pressure difference between the front and rear of the impeller and the hydrostatic force in the suction direction. In a centrifugal pump, 3D computer-aided analysis programs are used to design and reduce R&D and manufacturing costs. In this study, parameters affecting axial load of the centrifugal pump with a single suction and closed impeller were investigated by using the Computational Fluid Dynamics (CFD) method. In this context, the flow rate and the some physical properties such as the back gap of the impeller, wear ring and balancing holes, of the centrifugal pump were investigated to determine how much affected the axial load. The results showed that the wear ring and the balancing holes give rise to effective results on the axial load, while the back gap of the impeller does not affect the large extent. With the design changes made with these parameterizations, the axial force was reduced by up to 60%, whereas the efficiency was decreased by 5%. The loss of efficiency due to this decrease in axial force is negligible. However, higher efficiency values were also found at a different point from the working point where the axial load is lowest.

The pile foundations mostly support large marine structures, tall buildings, and windmills subjected to lateral cyclic load and eccentric axial load. Many studies have shown the influence of loads that may be only the cyclic lateral load on the performance of groups of piles without considering the effect of the eccentricity of vertical loads. Thus, the experimental laboratory studies aimed to know the effect of the eccentricity of axial static load on the behavior of foundations like the group of piles that were positioned to lateral cyclic loads. This study used 2x2 pile groups. The piles are squares made from aluminum and embedded in the soil with RD equal to 70% (RD = relative density) obtained by using raining technique for the sandy soil. Three pile spaces were used (i.e., S=3D, 5D, and 7D), where S is the meaning of the spacing of the cap of the group pile, D is the meaning of the diameter of piles, L\\D is equal to 40 when L is meaning the length of the pile and CLR (cyclic loading ratio) =100%. It can be concluded that when there is an eccentric axial load with a lateral cyclic load that influences pile group performance, the lateral displacement increases up to 30% for the pile’s group(3D) in the eccentricity (+1) compared with the center axial load (0). The maximum lateral displacement of this group in +1 was (8.5 mm).

Ultra-high-petformance concrete (UHPC) enables thinner, longer-span elements withfewer or no reinforcing bars. This study investi-gates the shear behavior of reinforcing bar-free UHPC panels with a thickness of 4 in. (101.6 mm) and 2.0% volumetric content of straight steel fibers. The panels were tested under combined shear and axial loads using the universal panel tester (UPT) facility. The UPT experiments were complemented with small-scale direct tension tests (DTTs) and large-scale tension strip tests (TSTs) to investigate the effect of UHPC tensile characteristics on shear. The panels exhibited ductile responses with post-peak residual shear capacities higher than 20% of the maximum shear stress, with the TSTs providing an improved correlation to UHPC shear than the DTTs. Test results showed that the relative effect of axial loads on UHPC shear can be greater than the relative effect on conventional concrete per ACI 318. It was alsofound that a correlation exists between fiber alignment and UHPC's tensile behavior, which can alter the localization stress by as much as 39%.