Applied Mechanics and Materials Vols. 117-119

Abstract: High-entropy alloy of NiCoCrFeMnCuC were made by vacuum non-consumable arc furnace in the present work. The crystal structure of NiCoCrFeMnCuC was analyzed by XRD. The corrosion resistance of NiCoCrFeMnCuC in 10%HNO₃-3%HF, 10%H₂SO₄, 5%HCl and 10%HF was investigated, respectively with weight loss experiment. The results show that main intermetallics of the alloy are CoC_x, FeNi₃ and Fe₃Mn₇. The NiCoCrFeMnCuC has simple crystal structures with face-centered cubic crystal structure FCC and Quartet and has excellent corrosion resistance in some medium acid liquids.

Abstract: In the longer period under the effect of changing load, pile-soil interface properties will be soften. Therefore it will reduce the foundation capacity and increase the Foundation the settlement, and bring the project safety risk. The influences of interface properties weakening on bearing behavior of pile foundation were analyzed by mathematic calculation method. These results would be used for the research of foundation bearing behavior under variable load.

Abstract: A new approach is proposed to detect and track the moving object. The affine motion model and the non-parameter distribution model are utilized to represent the object firstly. Then the motion region of the object is detected by background difference while Kalman filter estimating its affine motion in next frame. Center association and mean shift are adopted to obtain the observation values. Finally, the distance variance and scale variance between the estimated and detected regions are used to fuse the observation values to acquire the measurement value. To correct fusion errors, the observable edges are employed. Experimental results show that the new method can successfully track the object under such case as merging, splitting, scale variation and scene noise.

Abstract: This paper presents the hydrodynamics of chopped oil palm fronds (OPF) from cold flow experiments carried out in a swirling fluidized bed dryer (SFBD). The chopped OPF was 10 – 15 mm in size and falls in between Geldart type B and D. The OPF which consisted of leaves and petiole (stem) were first separated before studied individually due to their different physical characteristics. 2 bed loadings of 120g and 140g were investigated for bed pressure drop, (ΔP_b), minimum fluidization velocity (U_mf) and minimum swirling velocity (U_ms) while regimes of operation were closely observed. The experiments yield that the OPF leaves and petiole have distinct hydrodynamic behavior due to their different bulk densities and voidage, hence suggesting drying should also be conducted separately unlike the current industrial practice. The leaves have lower U_mf and U_ms compared to the petiole and thus swirling motion was initiated earlier in SFBD when operating with leaves. Both samples however, have limited operating velocities due to elutriation. In conclusion, the SFBD was found to fluidize the chopped OPF well while providing good solid-gas contact which is highly desired for drying.

Abstract: The effect of initia gamma prime particle size on coarsening kinetics of gamma prime precipitates in Nickel-based superalloys has been studied by means of phase field method which takes into account the lattice misfit. The simulation shows that the gamma prime precipitate morphology at the late stage of coarsening is independent of initial particle size, and the rectangle-like precipitates dominate the matrix which is in good agreement with experimental studies. The coarsening exponent increases with initial size, while the coarsening rate constant exhibits no apparent regularity. Although the coarsening trend is independent of initial particle size, the precipitate size increases with initial size at a given aging time. Through precipitate size distribution calculation, it is found that the size distribution is fairly stable, which is not sensitive to the initial particle size.

Abstract: To obtain the cross-sectional distortion of thin-walled rectangular tube in rotary draw bending process accurately, a new method to exactly describe the distortion has been proposed. The coupling between the convex of the tube side walls and the concave of the tube flanges is considered in the distortion modeling. Combined with the experiments, the cross-sectional distortion obtained using the new distortion model are compared with the previous ones obtained without considering the convex based on numerical simulations. The results show that cross-sectional distortion obtained by current model is closer to reality than the previous ones. The distortion by current model is more safety in the practical bending process.

Abstract: This paper introduces a kind of electric hot milling method for T10A tool steel and analyses its feasibility. Collect temperature signals and vibration signals in the machining process by a set of signal acquisition system. Afterwards, process these signals by using wavelet transform and wavelet packet transform, compare and analyze them in different working conditions. The results of the study indicate that through comparison between dry milling and electric hot milling, the latter can be more effectively milling tool steel, and improve the cutting tool durability.

Abstract: According to the project requirements, U-shaped compartment was designed and analysed based on soil mechanics principle. The finite element models of U-shaped compartment structure were established, shell element was employed to mesh compartment. Analysis on the structure of the compartment against typical loading conditions was carried out to get the stress distribution of the compartment structure.

Abstract: A new method for vibration control of aeronautical thin-walled workpiece in high-speed milling progress using a dynamic vibration absorber is presented. First, the theoretical model of the method is established and studied. Then the effectiveness of this method is testified via the simulation based on FEM. Finally, the feasibility of this method is discussed. The result shows that this method for vibration control of the aeronautic thin-walled workpiece in high-speed milling progress is effective and practical.

Abstract: To study the post-fire behavior of the profiled sheet-ceramsite concrete composite floor after exposure to fire load, experimental research on post-fire bearing capacity of a profiled sheet-ceramsite concrete composite floor subjected to dead load, which has shearing nails, is carried out here. Based on the experimental results, the post-fire bearing capacity of the composite floor after exposure to fire is analyzed. It is shown that the failure form of the profiled sheet-ceramsite concrete composite floor after exposure to fire has obvious change compared with the floor not subjected to fire load, but the composite floor subjected to fire load exhibits higher bending capacity, and the ultimate value of the equivalent distributed load is up to 30.86 kN/m2, which may be used as basis of strengthening and repairing of the profiled sheet-ceramsite concrete composite floor after exposure to fire.