Applied Mechanics and Materials Vols. 490-491

Abstract: The precision analysis of surface model is one of the key technologies in reverse engineering.Analyzed the error sources of surface accuracy in reverse engineering,proposed an evaluation indicators of the surface accuracy,which are whether the reconstructed model is qualified.Taking rearview mirror for example,compared with the reconstructed model and the original point cloud data by three-dimensional and two-dimensional methods in Geomagic Quality software,obtained the deviation value of the whole model and three different directions,the results show that the error of the most data points is in the range of permissible,which is less than the pre-set error;take the reconstructed surface data and the original point cloud data for comparison, more than 94% of the total data points is in the range of permissible, prove that the fitting surface accuracy is qualified.

Abstract: As two important methods of array signal processing, blind source separation and beamforming can extract the target signal and suppress interference by using the received information of the array element. In the case of convolution mixture of sources, frequency domain blind source separation and frequency domain adaptive beamforming have similar signal model. To find the relationship between them, comparison between the minimization of the off-diagonal components in the BSS update equation and the minimization of the mean square error in the ABF had been made from the perspective of mathematical expressions, and find that the unmixing matrix of the BSS and the filter coefficients of the ABF converge to the same solution in the mean square error sense under the condition that the two source signals are ideally independent. With MATLAB, the equivalence in the frequency domain have been verified and the causes affecting separation performance have been analyzed, which was achieved by simulating instantaneous and convolution mixtures and separating mixture speech in frequency-domain blind source separation and frequency domain adaptive beamforming way.

Abstract: This paper firstly introduces the composition and mathematical description of the capacitance sensor, meanwhile, establishes the mathematical and finite element model of it. According to previous finite element model as mention above, this paper bases on FEM to compile the program and calculate the distribution of potential with shield and no shield. The program obtains result of the contour figuer of every node. Then comparing the potential value on nodes at the same place. In terms of previous analysis result, this essay amis to change electrode plate width and the length of radial shielding electrode by the order. In the meantime, it also research Potential value change in the same area and analyze the influence of potential distribution in those electrodes that were affected by the width of electrode and length of radial shielding electrode. In the end, this study obtains a lot of useful conclusions for the capacitance sensor design.

Abstract: The generalized thermoelastic diffusion problem with temperature-dependent properties is investigated in the context of the theory of generalized thermoelastic diffusion. The results show that all the considered variables have a non-zero value only in a bounded region and vanish identically beyond this region, and the temperature-dependent properties act to reduce all the considered variables.

Abstract: At present, large components in airplane structural assembly are assembled with the aid of large fixed or partly adjustable devices dedicated to the relevant version. Some of the disadvantages of these systems are the limited range of possible adjustments of the handling devices and low flexibility. This restricts the assembly of different versions or products because the equipment cannot be adequately adapted to the version-specific requirements and geometry of the product. This paper describes a solution for a versatile assembly system for large structural elements which can be configured according to specific requirements employing a modular mechatronic building block with reconfigurable handling modules (robots). Motivation

Abstract: Large gantry machining centers are used for machining of products in almost all industry. To raise the design and production efficiency of machining centers, an integrated method of fast design and analysis is proposed in this paper. Firstly, large components unit structures are decomposed and extracted based on functions and structures. Then, after conducting fast analysis using APDL programming, a method of Comprehensive Evaluation is employed to optimal select the design schemes. Finally, the column of large gantry machining center QLMT6300 is taken as example to illustrate the validity of the method presented.

Abstract: Under the requirement of equipment support work from "equipment type-based" to "equipment competency-based", the equipment maintenance support personnel should be rational defined from the perspective of equipment system. This paper defined the requirement of equipment system support personal using the utilization rate, and gave application examples..

Abstract: Based on Newmark-β gradual integration method and elastic-plastic mechanical theory, numeriacl analyses of effects of soft soil depth and thickness and pile length on the characteristics of horizontal seismic response of bridge-foundation interaction system with soft layers conducted by using finite element program Midas/GTS. The numerical results show that: (1) The high frequency components of seismic excitations can be filtered and the low frequency components are amplified correspondingly when seismic waves are transmitted through soft soil layer, and thicker and lower soft soil layer can amplified this effects; (2)The extremum force of abutment shows decreases first then increases with depth decreasing, and displacement of abutment top and bottom has the same law with seismic waves, and the thicker and lower soft soil layer or shorter piles can aggravate abutment force and deformation; (3)Shear extremal stress shows decrease from top to bottom and the thicker and lower soft soil layer or shorter piles are adverse on piles; (4)Moment extremal expresses first increase then decrease with pile length and the lower and thicker soft soil layer or shorter piles can enlarged piles moment.

Abstract: Fan nozzle is the core component of tool cooling system, but the study on spray characteristics of the nozzle is not deep enough. Solid Works model of fan nozzle was established in this paper, the injection characteristics of nozzle are simulated by FLUENT analysis. Influence law of the injection characteristics of fan nozzle was studied by changing some parameters of fan nozzle spray in the process, such as liquid viscosity, nozzle flow, operating pressure and surface tension. The simulation results show that in the case of other parameters are the same, the higher the operating pressure is, the higher the jet velocity of fan nozzle is, the jet diffusion of fan nozzle along a flat direction increases firstly and then decreases; The higher the liquid surface tension is, the smaller the jet diffusion of fan nozzle along a flat direction, but the influence of liquid surface tension to the jet velocity of fan nozzle outlet can be neglected.

Abstract: This paper presents homing and docking autopilot design for the autonomous underwater vehicle (AUV). A nonlinear interrelated dynamic model of the underwater vehicle is considered. The AUV autopilot is designed on base of a position-trajectory control method. Adaptation of the control system is based on robust disturbances estimation. Modeling and hardware results approved feasibility of the proposed methods.