Applied Mechanics and Materials Vols. 496-500

Abstract: A constraint condition finite element analysis mode of the high speed PCB drilling machine Z-axis bottom plate was established on the platform of Abaqus. And then an optimal structural mode of a Z-axis supporting plate was obtained by means of performing constraint modal analysis and dynamic analysis optimization on the structure of the Z-axis supporting plate. modal tests and analyses were performed on the Z-axis plate before and after the optimization with the application of an LMS vibration/dynamic signal acquisition and analysis system. The experimental results were shown that the tested Z-axis plate dynamic characteristics were basically consistent with the obtained Z-axis supporting plate mode from simulation analyses using the finite element software Abaqus. It was proved that using the finite element software was feasible for optimizing the Z-axis supporting plate structure.

Abstract: Due to higher energy consumption for air-condition system and higher energy cost for building, the combination between peak-valley power price and chilled energy storage is provided and paid more and more attention. This paper introduced main chilled energy storage technologies and analyzed their economic performance, chilled water storage and ice storage both have good performance, but they fit for difference conditions, for chilled water storage, it doesnt need to add chiller for below zero temperature and fits for energy saving reform, and ice storage can meet the need of new air-conditioning system, which supplies a new application direction for energy cost saving operation in building.

Abstract: Study the linear and nonlinear stiffness dynamic characteristics of ball screw in feed system. According to the structure and the stiffness of ball screw, considering the influence of damping force, elastic force, friction force, driving force and load, establish the dynamic model of feed system. Use Linz Ted- Poincare (L-P) Method of singular perturbation to solve the model, obtain the quadratic approximate solution of the free vibration, analyze the multiple solution phenomenon of the model, and also conduct the numerical simulation analysis for the model.

Abstract: Coupling is mostly used for the connection of two shafts, widely in ship machinery. Because the vibration and impact of propeller under alternating load, the tail shaft work conditions are harsh, pre-tightening force plays an important role in the performance of tail shaft coupling. In this paper, based on conventional coupling, achieve pre-tightening by applying pre-tightening lock bolt at the circumference of pre-tightening nut, determine the pre-tightening force according to empirical formula, analyse the pre-tightening strength by using of Workbench finite element software, get the stress distribution of related parts, to explore the effect of pre-tightening force on the stress of related parts of coupling.

Abstract: With the development of auto maintenance technology the applications of vehicle in the car maintenance teaching are becoming more and more. But it is inconvenient and not intuitive on the whole vehicle fault setting and testing. Especially at the time of data measurement this will increase the loss of the vehicle. So this will make it more practical significance to substitute vehicle teaching experiment platform for the vehicle in the teaching. This makes it necessary the research and production of vehicle test bench. Here we will research the Nissan car test bench in the production and use process.

Abstract: With the rapid development of high-speed railway, the problem caused by railway has become the focus of public attention. Whether the railway will damage the electromagnetic environment become an unavoidable topic. Choosing the AC 25KV high-speed railway to study, the impact of its resistive coupling on the human body or different devices is explored. Using the existing analytical formula, the ground potential rise caused by the resistive coupling has been simulated, which intuitively show the different ground potential rise in different situations. Finally, the impact of resistive coupling has been analyzed.

Abstract: Drawing devices, as an important auxiliary equipment, nowadays widely applied in areas such as mechanical installation, machinery manufacturing, machinery repair, but still have problems to fit into the workpiece of larger size and of difform shape. The article presents a new kind of drawing device with a novel drawing die,which not only well solve the problem mentioned but also greatly improve the use efficiency and the use value by analyzing the existing deficiency in drawing devices.

Abstract: In this paper, based on the principle of induction heating and eddy current fields working, the equivalent circuit model of induction cooker heating was proposed and analyzed. By using the finite element numerical analysis software, the optimization design and model simulations of induction cooker were implemented. Finally, a new design of induction cooker with the uniform heating-coil was proposed, and the magnetic circuit modeling and simulation of new type induction cooker heating was carried out, the eddy current loss density distribution in the common wire coil and the improved wire coil was separately calculated and compared. The results shown the new wire coil had higher energy efficiency and more uniform heating characteristics, which provided a reference for the future optimization design and development of induction cooker.

Abstract: This paper presents a new transformative manufacturing methodology for free-form machining. An experimental prototype machine is constructed to levitate and rotate an object attached with sharp edges, which act as a cutter for the purpose of performing machining processes. This device aims to lead to a technological breakthrough, overcoming the limitation of the workpiece features, and achieve greater free-form machining capability. The construction of curved holes and interior surfaces are constrained by the geometry of the machine tool. The proposed concept creates a new device that uses a magnetic field generator as a base. It is loaded with a constant power imposing a vertical physical force to balance gravity and stabilize the cutting tool. With the uniqueness of a preferred orientation between the tool and the base, a rotating surface placed below the base permits the rotation of the cutting tool in order to achieve desired tool rotation speed. A smooth and controlled cut is achieved on a soft material. The result shows the feasibility of the device to achieve similar outcomes as a machine tool.

Abstract: Thispaper adopts the crack line-field method to analyze finite-width stiffenedplates with central through I-type crack under uniaxial tensile loading. Themethod completely abandons the small scale yield hypothesis. The plastic stressand strain fields at crack tips and the plastic-zone length can be accurately determinedby combining with equivalent shear stress of Westergaard stress function in theposition of stiffener. It can be seen from the illustrative example that theresults of the paper agree well with those by finite element method.