Applied Mechanics and Materials Vols. 66-68

Abstract: Movable mine refuge chamber is widely used in coal mines for protecting miners from coalmine accident. During a coalmine accident, there will be large heat impact load and stress on the movable mine refuge chamber caused by high temperature and high pressure. Therefore the strength of the movable mine refuge chamber should be carefully designed to meet the safety requirement with the possible lightest weight. Based on analysis of the structure dimensions, material properties, and operating conditions, a finite element model is developed with an emphasis on the effect of the layout and sizes of stiffeners and structural form of the chamber. A comparison of different design schemes is made and the calculation result is given. This work could be helpful for optimization design of China’s movable mine refuge chamber.

Abstract: A novel approach is presented to solve the propagation of Lamb wave in a pre-stressed plate with finite thickness, where the commonly used Helmholtz decomposition method fails to find the solution. By using the proposed approach, some important relations of Lamb wave such as the dispersion relation can be obtained and analyzed in closed form, and the effects of initial stress are discussed in details. The method presented herein can be developed further to study the mechanical behaviors of other surface wave acoustic devices.

Abstract: Based on the principle analysis of two-axis linkage and cut point tracking crankshaft servo grinding technology, the principle of triaxial linkage and cut point tracking for crankshaft servo grinding is analyzed and researched on the technological advantages for the neck of crankshaft connecting rod and the spindle neck. Then the dynamic grinding model is established, and the high-precision liquid hydrostatic slide-way technology, high rigidity straight line drive technology and on-line measurement and error compensation technology are employed synthetically to solve the dynamic performance of moving parts for ultra-precision grinding and its influence on the machining accuracy successfully. The problem of using common corundum wheel to process the crankshaft neck and connecting rod efficiently and accurately is conquered.

Abstract: Post-earthquake restoration and reconstruction work is a huge social project, the disposal of post-earthquake property is a complex and urgent issue. At present, the research on this area is still in a preliminary stage. By means of comparative studying on domestic and international documents, this paper classified the post-earthquake property, through the case study of Beichuan and field test of local post-earthquake property disposal situation, analyses the problems existing in the current mechanism, puts forward a scientific and rational suggestions, expecting to solve the problems and conflicts, promoting social stability and development in earthquake stricken area.

Abstract: The school-enterprise cooperation is an important way to train highly-skilled personnel, improve independent innovation capacity. This paper based on the research of the current school-enterprise cooperation mode and its obstacles, analysing the operation mechanism of this mode, and thus proposing a rational choice of sustainable operational mechanism for building a school-enterprise cooperation mode of training high-skilled talents.

Abstract: Today, with increasing competition, enterprises are facing unprecedented challenges. How to identify clients has become an important project in the development of competition among enterprises. Client identification based on association rules will be conducive to the innovation of traditional business management thinking. An effective method for client identification should be carried out with exploratory data analysis, improving ability to identify clients for enterprises and finding more interesting, more practical and more specific association rules between the data.

Abstract: Based on the analyses of the current research status of PC + NC type control system in micro-machining technical field both at home and abroad, an “IPC + PMAC motion controller” type open CNC system is established. Control circuits of the micro milling machine control system are designed, which include the realization of the functions of spindle status display, feeding tables status display, IPC status display, machine tool alarm, interlocking control of the function buttons and the corresponding indicator light control of spindle cooling, spindle lubrication, spindle alarm and spindle running status. Finally, the safety inspection function of the spindle is achieved through writing corresponding PLC programs. The research of this paper can provide reference for the study of the micro milling machine control system.

Abstract: Creative design plays a quite important role in mechanical product processing, which affects the mechanical development of all over the country. Much research on the mechanical design is carried on. The paper is mainly based on Yan’s Creative Mechanism Design Methodology, in which the author carries out some research in Type Synthesis based on the Number Synthesis Method. And kinematic chains of eight links and ten joints can be gained from embryo graphs. In the article, the author proposes a systematic method for the creation of a sofa bed. In the process, some rules are brought in, and the original structure is changed for other structures with the same functions but different shapes. At last, many probable schemes different from the original mechanism are obtained. The next step is to choose the most proper scheme in order to carry on the further analysis.

Abstract: In every filed of natural science, more and more researchers attach importance to system quantitative analysis, control and prediction. In filed of automatic control, system identification is the extension of system dynamic characteristics testing. System modeling is the basis of system identification, non-parametric model can be obtained by means of dynamic characteristics testing, but parametric model must be established by means of parameter estimation algorithm, which is more prevalent than dynamic characteristics testing. Coal power plant produces more gas and dust, so how to control the fan system plays a very important role in environment protection. We must clarify the parameter of fan system before controlling it. The traditional Bayes identification algorithm is used widely in research and industry, and the effect is relatively good. The paper induces the concept of loss function based on traditional Bayes identification algorithm, and proposes an improved Bayes identification algorithm, which can be applied to fan system identification successfully.

Abstract: In this paper, in order to solve the abnormal noise in the pickup while it accelerated or decelerated, the test was done through the use of LMS Test.Lab system, the spectrum and correlation analyses of vibration and noise were carried out, then it was known that the noise source was turbocharger. The farther research direction and improvement measures were given.