Applied Mechanics and Materials Vol. 623

Abstract: It remains unresolved to study the relation between the density of wedge and its impact. Fluent is applied to simulate its mechanism with 6DOF model. After the comparison of numerical result and the theoretical, it matches good and then the transient free surface scene is observed. Thus Fluent is able to solve this kind of non-linear problem. And the effect of density of wedge on the slamming character is also studied.

Abstract: In this paper, we consider hyperbolic Timoshenko-type vibrating systems that are coupled to a heat equation modeling an expectedly dissipative effect through heat conduction. We use semigroup method to prove the polynomial stability result with assumptions on past history relaxation function exponentially decaying for the nonequal wave-speed case.

Abstract: High-speed motorized spindle of NC machine tools is the core component for high speed machining. Production efficiency, machining accuracy, processing quality are greatly improved, and production cost is reduced by high speed machining. The paper describes the common failure modes of high-speed motorized spindle. By the fault tree analysis method, failure modes of motorized spindle are modeled, and the main fault reasons of motorized spindle for NC machine tools are gotten. Qualitative analysis is performed for the fault tree by the mean of the structure function. At the end of this paper, the minimal cut sets which are the main sets of failure modes are all obtained. It has laid a good foundation for further study of quantitative analysis of motorized spindle failure modes.

Abstract: A finite element method is introduced to simulate ice failure based on multi-surface criterion. The effects of porosity, temperature and strain rates on the ice mechanic property are taken into consideration. The main principle to simulate environment is explained. Through second developed to the finite element software, the process of ship-ice interaction is simulated. And the ship motion, ice force and ice failure mode are predicted by this method. The result is compared with other papers. the numerical simulation phenomenon is nearly same with the actual process. It suggests that simulation is reasonable, and the model has potential value in simulations of assessing ship strength. The fatigue damage is pointed out to be a special problem in ice-going ship design.

Abstract: We study the Cauchy problem for the convection-diffusion equation, which describes physical phenomena where particles, energy, or other physical quantities are transferred inside a physical system due to diffusion and convection processes. For, we show the continuous dependence upon the initial data. Moreover, asymptotically self–similar global solutions are investigated with nonhomogeneous initial date.

Abstract: This work presents a method for metal coating of the surface of optical fiber by means of electroless and electroplating. No vacuum techniques or any high-temperature methods are required. The coating method presented in this work is developed with emphasis to further embedding the coated fibres into solid metal using. The method is based on electroless and electroplating, and therefore, the fibres can be coated with any metal or metal alloy applicable by this technique.

Abstract: With the requirements of machining develop towards high precision, high efficiency, intelligentization, combination and greenization, in this paper we develop a NC spherical turning and grinding machine tool with high precision and combination to meet the brisk demand of market for spherical workpieces with large diameter and high precision. According to the enterprises’ practice results ,our machine tool can finish machining of large diameter and high precision sphere quickly, with high quality and low cost, and it has a high practical value.

Abstract: JCO forming is one of manufacture mode widely used in production of large diameter submerged-arc welding pipes, in which JCO forming process is progressive multi-step air bending. In order to improve JCO forming quality, it is necessary to analysis deformation characteristic of air bending. So, air bending is analyzed using finite element method. Taking the air bending of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the air bending is simulated by finite element (FE) code ABAQUS. In this paper, the simulation data is validated by experiments and a comparison showed a good agreement with experiments results. The stress/strain from simulation is discussed. Thus, the results of research provides a basis to improve JCO forming quality.

Abstract: JCO forming is one of manufacture mode widely used in production of large diameter submerged-arc welding pipes, in which JCO forming process is progressive multi-step air bending. In order to improve JCO forming quality, it is necessary to predict springback of air bending. In this paper, air bending is simulated using finite element method, but simulation parameters directly affected prediction precision. So, taking the air bending of X80 steel Φ1219mm×22mm×12000mm welding pipe for instance, the air bending is simulated by finite element (FE) code ABAQUS. The effects of simulation parameters on springback is discussed. Thus, the results of research provides a basis to improve prediction precision of springback in air bending of JCO forming.

Abstract: Cutting forces modeling is the basis to understand, simulate milling process and further to control milling process parameters for obtaining higher precision workpieces. With the development of engineering technology, FEM can be used to simulate metal machining process and gain better understanding of material flow within dies, so as to optimize tooling to eliminate tears, laps and other forging defects. In this paper, the calculated cutting force increases approximately logarithmically with the cutting speed, as should be expected from the logarithmic rate dependence.