This paper presents numerical investigation of circular concrete-filled aluminum tubular (CFAT) stub columns under axial compression. The numerical models were developed using the finite element (FE) package ABAQUS. The parameters commonly employed in conventional CFST FE modeling have been discussed in this study. The nonlinearities of concrete and aluminum materials and the interaction between concrete and aluminum tube were considered. Numerical models were validated against collected experimental data. The ultimate loads, load-axial strain relationship and failure modes from numerical simulations were compared with those from experiments. The verified FE model was used to analyze structural behavior of full histories of the corresponding load-deformation N-ε response. Load-deformation N-ε curves for both concrete and aluminum tube were also presented. Upon on validation of the FE models, additional structural performance data over a wide range of diameter-to-thickness ratios, aluminum grades and concrete strengths were generated for parametric studies. The influences of diameter-to-thickness ratios, aluminum grades and concrete strengths on the ultimate strength were presented in this paper.

This paper presents numerical investigation of circular concrete-filled aluminum tubular (CFAT) stub columns under axial compression. The numerical models were developed using the finite element (FE) package ABAQUS. The parameters commonly employed in conventional CFST FE modeling have been discussed in this study. The nonlinearities of concrete and aluminum materials and the interaction between concrete and aluminum tube were considered. Numerical models were validated against collected experimental data. The ultimate loads, load-axial strain relationship and failure modes from numerical simulations were compared with those from experiments. The verified FE model was used to analyze structural behavior of full histories of the corresponding load-deformation N-ε response. Load-deformation N-ε curves for both concrete and aluminum tube were also presented. Upon on validation of the FE models, additional structural performance data over a wide range of diameter-to-thickness ratios, aluminum grades and concrete strengths were generated for parametric studies. The influences of diameter-to-thickness ratios, aluminum grades and concrete strengths on the ultimate strength were presented in this paper.

Based on the dangers of suspended oil mist microparticles from machining to the environment and health of worker. A theoretical analysis on the generation mechanism of cutting fluid oil mist and an experimental study on its influencing factors were carried out in this paper. The experiment was conducted in closed lathe with flood cutting fluid feed system. A droplet diameter measuring system was equipped in the dense region of oil mist, which enables to observe the droplet distribution in air and scan the morphology of a single droplet accurately through its confocal microscopy. Droplet distribution and diameter were calculated through computer. In the experiment, effects of influencing factors on the oil mist concentration and average droplet diameter were discussed by controlling the revolutions per minute (rpm) of the main axis and cutting fluid flow, respectively. Experimental results demonstrated a significant effect of rpm on the characteristics of cutting fluid oil mist.As the rpm increased, the average droplet diameter decreased, whereas the oil mist concentration increased. As the cutting fluid flow increased, both of average droplet diameter and oil mist concentration increased.

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The glass ceramics based on steel slag and blast furnace slag presented light-khaki color to deep-brown color with increasing content of steel slag. The major crystalline phase is gehlenite (Ca2Al2SiO7) with minor akermanite phase (Ca2MgSi2O7) for all the samples. Decreasing Al2O3 and increasing Fe2O3 in the samples increased glass viscosity, and decreasing SiO2 decreased the amount of liquid phase. Both the above effects result in the increasing optimum sintering temperature. The grain size and amount of crystalline phase were increased with content of steel slag. The bending strength of the samples first increases with content of steel slag up to a maximum 90 MPa, then decreases. The bulk density of the samples decreases with increasing content of steel slag, from 2.76 g/cm3 to 2.60 g/cm3, owing to lower content of glass phase during sintering process. The samples exhibit good chemical resistance, and the weight loss values in alkali are lower than those in acid. Therefore, the glass ceramics based on steel slag and blast furnace slag may have great potential for applications as building decorative materials, and it provides a promising way for the utilization of steel slag.