Advanced Materials Research Vols. 308-310

Abstract: Based on the development of forestry machinery and the causes for tractor accident, this paper analyzed the necessity of improving the small skidding tractors. Then the automatic overload alarm and automatic anti-tipping alarm were designed through the research on overload and tipping point of small skidding tractors. The main parameters of the devices were calculated, the operational principle was described and the two wiring diagrams were given. The feasibility of these two alarm devices is proved theoretically in this paper. Two ways are provided to improve the safety of logging operations of the tractor and an effective research method for its intelligent development in China is planed.

Abstract: In the process of shield tunneling construction, the energy consumption is a prominent issue. The disc cutter blade angle, blade tip width and corner radius are taken as design variables, and the minimum cutting special energy consumption as the target, the structural parameter optimization model of disc cutter is established. Genetic algorithm (GA) is used in the mathematical model, and the optimal solution is shown: the disc cutter blade angle is 26°, the blade tip width is 8 mm, and the corner radius is 5 mm. Compared to the actual construction data, the results are satisfactory.

Abstract: For generating a more reasonable initial layout configuration, a three-dimensional topology optimization methodology of the steel-concrete composite structure is presented. Following Solid Isotropic Material with Penalization (SIMP) approach, an artificial material model with penalization for elastic constants is assumed and elemental density variables are used for describing the structural layout. The considered problem is thus formulated as to find the optimal material density distribution that minimizes the material volume under specified displacement constraints. By using the adjoint variable method for the sensitivity analysis, the optimization problem is efficiently solved by the gradient-based optimization algorithm. Numerical result shows that the proposed topology approach presented a novel structural topology of the simply-supported steel-concrete composite beam.

Abstract: A new inverse algorithm is proposed for the reconstruction of the total heat exchange factor, which is concerned with transient heat conduction problems. The unknown total heat exchange factor is treated as the optimization variable, and the errors to be minimized are the differences between the calculated temperatures and the measured ones. The sensitivity coefficients are obtained by the complex-variable-differentiation method. The effectiveness, efficiency and accuracy of the inverse approach are demonstrated in few test cases.

Abstract: Based on lines of technological system evolution in TRIZ, the seminar analyzed the current situation of the stereo garage development, summarized the evolutionary lines, mapped out the potential evolution diagram of stereo garage combining with improved evolutionary potential diagram, and concluded evolutionary potential in automation, spheroidality, intellectualization, standardization and multi-systematic. Based on the above, a new model for conceptual design of the stereo garage was raised. The success of the design and trial production of new stereo garage indicated the feasibility of application of technical system evolution law in predicting the future development of product.

Abstract: The analysis of motion and mechanics property was carried out on the five hinged incline arranged and double elbowed force increasing mechanism of injection machine. A complete optimization designing procedure was carried out by improved ant colony algorithms, so as to increase the stroke ratio and the amplification of the force, and to decrease the total length of mechanism. Its optional mathematics model was established. The procedure of optimal design belongs to multi-object optimal problem. The optimal solution of the force increasing mechanism was found with improved ant colony algorithms. Compared with the traditional methods, the result shows that the total length of mechanism is decreased, the stroke ratio is increased, and the amplification of the force is increased. Furthermore, a sensitivity analysis of various design parameters has been performed to observe changes in injection performance parameters, and results show that the length of back elbowed bar and the length of connected bar have a significant impact on the performance measures. And the results recommend that the close clearance of the length of back elbowed bar and the length of connected bar must be maintained. Therefore it can provide some valuable instruction and theory to engineers. The instance of 1000 N large-scale injection molding machine is taken as an example to demonstrated that such method is effective and practical.

Abstract: This paper is based on the urgent problem of furniture industry that is to increase the utilization of sheet material and improve the speed of sheet material discharging as the goal. To the problem of the cutting and nesting of the artificial board of CNC bothway Panel Saw analyses the “one size fits all” which under the technology constraint proposed the constrained condition of optimization of cutting. And optimization algorithm of two-dimensional sheet material nesting of rectangular pieces is studied and established a mathematical model. Using the Heuristic algorithm to solve the problem of two-dimensional rectangular pieces. The introduction of rules of location rules, combination rules and adjacency rules to make nesting layout reasonable and make the cutting process simplify.

Abstract: The overall flow time of the coating workshop for cutting tools is set as the scheduling objective. The problems of production scheduling of coating workshop are described in detail, then the simulated modeling of the problems is constructed in the eM-Plant software, and the simulation model combines the genetic algorithms to solve the processing procedures. Compared with the simulated results at last, it is obvious that the production scheduling is greatly optimized and of excellent stability with genetic algorithms.

Abstract: Q390 steel owns lots of good mechanical properties, it is used in many fields. By means of Gleeble 1500D thermal simulation machine, high temperature tensile tests were carried out; by OM,SEM, the fracture pattern and the microstructure of different distance from the fracture were watched and analyzed; by means of hardness test, the micro-hardness of different distance from the fracture was measured. The results show that the rupture at different temperature belongs to ductile rupture, with distance increasing from the fracture, the microstructure changes from composition structure of martensite, bainite, residual austenite into base metal structure, the grain size is smaller and smaller. The fracture hardness increases firstly and decreases secondly when tensile temperature increases, it is up to the max when temperature is 1200°C, the value is 395HV; the micro-hardness increases firstly and decreases secondly with distance increasing from the fracture, the hardness is the max when distance is 10mm,8mm,10mm at 800°C,1000°C,1200°C tensile temperature, the max value is respectively 330HV,340HV,370HV.

Abstract: Fluid jet polishing (FJP) is a computer controlled polishing (CCP) process. As the water effect of concave optics surface, the slurry won’t spread immediately until component have a basinful, and jet goes through a layer of slurry firstly before impact in FJP process, the submerged jet will influence material removal rate and bring on inaccurate fabrication results if it is not considered. In this paper, submerged jet characteristics are studied, and researches were taken for submerged jet polishing by simulation with FLUENT software and experiments analysis. Based on that, mathematical material removal correction with submerged depth is established for semi-submerged jet polishing. A BK7 concave surface was polished by semi-submerged jet with removal correction. The results show an affirmative proof for correction in submerged jet polishing.