Applied Mechanics and Materials Vol. 459

Abstract: Aiming at the low efficiency of handwork and high labor intensity, an automatic solution for perforated discs assembly is developed based on computer vision. This technology consists of the processes of material feeding, parts handling, circle detecting and assembling. The mechatronic structure includes the pneumatic elements and electric actuators that controlled by PLC and stepper motor drivers. This method has solved the problem of the large cost of human force since this product has a big industrial production. Meanwhile, a contour optimized Hough circle transform (CHCT) is proposed. It can overcome the standard Hough circle transform (HCT) s disadvantages, such as redundant calculation and probability of failures. It enhances the reliability in order to satisfy the demand of industrial automatic production. The image processing takes only about 60ms and reaches 100% success rate with a small detection error. This method also has the generality for the similar assembly system based on machine vision.

Abstract: Three-dimensional modeling and finite element analysis on the diesel engine piston is carried out in the paper. The distribution of temperature, stress and strain within piston at the rated conditions of the engine are obtained from the simulation. The calculated temperature is consistent with the results of the piston surface temperature which is obtained by hardness plug method, thus confirming the model's validity. The calculated maximum temperature is 374 °C and the minimum temperature is 144 °C. The maximum stress is 118MPa located between the piston skirt above the pin hole and the third ring groove. The maximum thermal strain appears at the piston top with the value of 6.29×10^-3. Finally, the temperature simulation of the piston adopted oil-splashing cooling is implemented. It is proved that thermal load can be further reduced through cooling measure.

Abstract: Soot oxidation temperature by high frequency electromagnetic energy was proposed using numerical simulation by combining electromagnetic with transient thermal analyses. Equation of electric field distribution in a microwave cavity with perfect electric conductor surfaces and TE₁₀ mode is formulated from Helmholtz equation. The dissipated heat distribution is calculated from the electric field distribution. Six study cases for electric field and dissipated heat distributions were implemented by using ANSYS software based on finite element method. The impact of dielectric sample properties, position, size and shape inside the microwave cavity were predicted. The results from the simulation of electric field and dissipated heat were compared with available data in literature and showed the validity of the analysis. It was found that the electric field forming hot spots at penetration depth and front corners of the soot sample and penetration depth is equal to 12mm but equal to 0 for samples with dimensions less than penetration depth. Dissipated heat pattern depend on electric field pattern and dielectric properties.

Abstract: The paper gives an overview of the models implemented in a new toolset for Russian logging companies. The toolset consists of a number of optimization tools, including the routing and scheduling of roundwood and energy wood harvesting teams, the sequencing of harvest areas, the estimation of available forest biomass potential in harvesting sites, and the planning of forest road networks. The optimization of routes is based on a two-phase algorithm where a heuristic optimization method is used to choose the best transportation paths and dynamic programming is used to choose the daily tasks and vehicle routing. The toolset has been tested in logging companies located in Russian Karelia. The results show that the toolset can be used to support a wide range of planning decisions at company level including truck routing, fleet utilization levels, and choice of transport method under new infrastructure assumptions.

Abstract: This paper explains and demonstrates how to reduce time for preparation of 3-dimensional (3D) geometrical Computer-Aided-Engineering (CAE) model from 3D Computer-Aided-Design (CAD) data. In generally, CAE model preparation is labor intensive and takes long time. Main part of preparation work is simplification of 3D-CAD data to decrease mesh scale and without impacting the solution accuracy. The purpose of this study is to create automatic CAE model preparation technology for reduction of preparation time. In this study, automatic model preparation method is developed by using of geometrical and topological information of 3D-CAD data. Benchmark test is performed to proof the efficiency of the method.

Abstract: In Steelworks Split failures of the rolls with grooves on the 3-high-roughing mill stand occurred four times. Detailed analysis of all the elements which influenced the failure was carried out. Stress analysis shownthatthe most critical area of the roll is the 7.a caliber what is corresponding with fracture positions. The fatigue strength of the material in the caliber groove for fatigue life prediction was missing and fatigue strength is determined by experimental testing.

Abstract: By Lagrange equation, the dynamic equation of vibrating screen based on double compound pendulum with single motor driving was established. With simulation method, dynamic simulating model was built, and influences of pendulum installing position, stiffness of torsion damping spring of pendulum rod, initial installing angle and length of pendulum rod on motion characteristics of vibrating screen was discussed. Research results showed that, by choosing suitable stiffness of torsion damping spring or length of pendulum rod, this kind of vibrating screen may achieve the approximate linear trajectory, or normal elliptic trajectory of deck; when the angle between the rotating joint of pendulum rod and screen surface equals to initial installing angle of pendulum rod, the vibration of deck is most close to translational motion..

Abstract: This work demonstrates a technique for producing accurate wax patterns made from a high precision silicone rubber mold. Silicon rubber mold was cut into five components, which is the minimum number of components for assembling the silicone rubber mold. The advantages of this silicon rubber mold include savings in assembly time, reduction of human error while assembling the silicone rubber mold and good assembly precision. The shrinkage of critical dimensions can be controlled within 2.19%. Results reported here can speed up the velocity in the development of a new cylinder block in the motorcycle industry.

Abstract: Silicone rubber mold is frequently used in the indirect tooling. Automatic vacuum casting system is widely used to degas in the manufacturing of silicone rubber mold, but the cost of hardware is very expensive. A low-cost automatic vacuum degassing system is designed, build and test in this study. Optimized parameters for degassing process are investigated. The saving in the degassing time is about 23.4%.This system offers many advantages such as reducing human error of operator, reducing noise and air pollutions derived from the vacuum pump of the vacuum casting system.

Abstract: Due to introduction of new vehicle models, an automobile manufacturing enterprise usually needs to make corresponding adjustments of the facility layout of the door welding workshop. On the basis of analyzing the production process and logistics characteristics of the welding line, the facility layout of the workshop is improved and the production logistics cost is reduced by using the SLP (Systematic Layout Planning) and internal logistics analysis method. Finally, a real production example is given to illustrate the effectiveness of the proposed method.