Advanced Materials Research Vols. 538-541

Abstract: A finite element method (FEM) is used to make the modal analysis of the drive axle housing, the first ten natural frequencies and modal shapes are obtained. The parameter identification method is applied to obtain the experimental modes. There is a great agreement with the calculating modes and the experimental ones, which proves that the finite element method is rational. According to the theoretical analysis, the main deformations are bending and torsion at both ends of the drive axle housing and the deformation of the middle part is relatively high. The natural frequencies are at middle and high frequencies which are close to the mesh frequencies of the drive axle gears. Therefore increasing the thickness and redesigning of stiffened palates are applied to avoid the resonance region effectively.

Abstract: An introduction is made of a new method, which use computer to get an accurate unfolding drawing, to calculate the cutting stock of chemical container’s connecting pipe. Practice proved that this method is not only fast and convenient, but also accurate and reliable.

Abstract: Took a type of ceramics for daily use vertical type high pressure grouting machine as the object of study, study the stress and strain of its upper and lower mould plates. Established their 3D model by CAD software Pro-E, and then import them into finite element analysis software to analysis the value and distribution of the stress and strain. The analysis results can provide some reference for design, and have some engineering and practical value.

Abstract: Kinematic characteristics of double-rocker mechanism is analyzed. Based on variable ratio transmission characteristics of elliptical gear, elliptical geared double-rocker mechanism is presented. Kinematic characteristics of elliptical geared double-rocker mechanism is clarified. Eccentricity is optimized. The elliptical geared double-rocker mechanism with approximate uniform rectilinear motion is designed. The methods in this paper facilitate the innovation design of the mechanism with approximate uniform rectilinear motion.

Abstract: The multidisciplinary design optimization(MDO) framework for aeroengine turbine based on life and reliability which covers the total process is developed. The framework consists of three parts: design module of parts, subsystem and system. The parametric model and optimization of turbine components such as rotor, stator, disk, casing and axle, can be created in parts design module. The interaction in subsystems, such as rotor-stator interaction, blade-casing gap and tenon-mortise contact problem can be solved in subsystem design module. The system design module can give out the global optimal solution of the whole turbine. The MDO for an aeroengine turbine using this framework has been taken, the results show that the framework is available.

Abstract: Flow stability of samplers is a key factor in air sampling. However, most of the existing air samplers have the problem of poor stability. In order to enhance the stability, a constant flow air sampler (HL-1) has been designed: a single chip processor was added to the flow control part. The performance of the sampler was presented and comparison with a conventional sampler was made. Inter-sampler comparison tests were carried out by comparing (a) the indicating error (b) the repeatability (c) the consistency of the flow and (d) the timing error with a traditional sampler. The results showed the improved sampling apparatus performed better than the traditional one in respect of stability. It could operate in a predetermined range of flow and volume in an entirely reliable and predictable manner.

Abstract: The optimization of wind turbine blades can increase the generator power and annual output of electricity. Illustrated by the case of 2MW wind turbine, optimizing the blade chord and twist angle by POS algorithm. Modeling by BLADED, analysis the change of lift and drag coefficients, the power coefficient, maximum power of wind turbine, minimum power of wind turbine, wind turbine generating capacity before and after optimization. The results show: the aerodynamic efficiency of optimized blade increased by 4.833 than that before optimization. In the wind speed of 12 m/s (that is lower and normal speed), the average power coefficient is improved by 0.05. The minimum power of the wind turbine increased by 4% -15% .The maximum power of the wind turbine increased by 3% -9%. And the annual production of power increased by 0.25%.

Abstract: The temperature and curing degree of carbon fiber reinforced plastic (CFRP) are coupled during pultrusion. In order to figure out the real-time temperature and curing degree of CFRP, the heat transfer model and curing model for resin were established on the basis of curing kinetics and heat transfer theory, and solved by the combination of finite element, finite different and indirect decoupling methods. The fiber Bragg grating (FBG) sensors were utilized to monitor the temperature of CFRP on real-time during pultrusion, while the curing degree of CFRP was measured through Sorbitic extraction. Experimental results show that the simulation method is effective and reliable. According to the simulated results, artificial neural network (ANN) combined with fast elitist non-dominated sorting genetic algorithm (NSGA-Ⅱ) to optimize die temperature and pull speed for pultrusion process, and significant improvements were achieved.

Abstract: Abstract: Finite element analysis and fuzzy multi-objective optimization technique have been integrated to solve the die structure design of sheet metal forming by transforming fuzzy multi-objective problem into a normal optimization problem. A mathematical model of fuzzy optimization for bending die was established. A fuzzy goal set was constructed. The fuzziness of multi-objective functions and constraints were defined. The optimal solution and optimal constraint value of individual objective function in the feasible field were found using the genetic algorithms. An electronic part bending case shows that this approach is more effective and accurate than traditional finite element analysis method and the ‘trial and error’ procedure.

Abstract: The design of a new pre-tensional structure(FROMO® preload nut) applied in the large size of screw thread was introduced, the preload bolt is only beared with the pure tensile stress. The pre-tightening force for the preload bolt and pre-tightening torque for the jack bolts were calculated. The practice elongation value of the preload bolt was measured, and compared with its theoretical elongation value. The result shows that: the new pre-tensional structure has adequate strength, it can control the pre-tightening force accurately with manual acting spanner, it increases efficiency and ensures the safety of operating , and which has promised the good performance in the application of the projects.