Applied Mechanics and Materials Vol. 470

Abstract: In the paper is described the solution of unsteady temperature field of multilayer plane structures. Nonlinear material and thermal properties of each layer for high temperature and fire is used. Defining the boundary conditions and calculation of the temperature at the contact material layers of the conditions of equality thermal flux is performed. The compiled program NONSTAC programmed numerical solution of differential equations modified heat conduction Euler and Runge - Kutta method with a variable integration step length. This computer program solves one dimensional temperature distribution. It is possible to input appropriate thermal characteristics as a function of temperature and to take into account heat of hydration development and variation of environment temperature. Calculated temperatures can be used for stress and strain analysis of shallow foundations with slide joint in footing bottom and fire resistance of plate structures.

Abstract: For studying the working performance of the cutting header, the paper puts forward using DEM to study its dynamic breaking process when it is for cutting coal rock. The model of cutting header and the model of the two-dimensional DEM simulation analysis are set up separately. By applying reasonable mechanical model into coal rock particles and the cutting header, DEM simulation analysis of its cutting process is carried out. Such analysis is taken at different cutting speed. Then, the way of selecting working parameters is got. It preliminarily proves the feasibility of using DEM to analyze the working procedure of the cutting header and it provides a new research method for its optimization design.

Abstract: In this paper, FLAC3D is used to set up dynamic models of double layer, the data acquisition and analysis process of Steady-state Rayleigh method are simulated, and dispersion curves of Rayleigh wave are extracted. Studies are focused on the dispersion characteristic of Rayleigh wave in the medium with dipping layer. The results show that the presence of dipping layer has significant influence on the Rayleigh wave dispersion characteristic. The observed dispersion curves are different from the theoretical ones in 1D model. The deviations are much bigger than those caused only by the difference of the thickness below the two observation stations, and the deviations increase with the increase of dipping slopes. The extracted dispersion curves of Rayleigh wave are relevant to observation locations.

Abstract: The numerical simulation of the Y-type three-roller two stands cold rolling stainless steel/carbon steel double metal composite seamless steel tube process was conducted through the finite element analysis of the elastic-plastic by applying the MSC.MARC software. Based on the numerical simulation, the character of stress and strain distribution parameters during the Y-type three-roller two stands cold rolling were obtained by the finite element analysis, and acquired the section pass deformation figure. The distribution of the axial stress, circle stress and radial stress were drawn below the Y-type mill along the circle. The mechanism of the tube cold rolling process and the effect of the forming steel tube both the diameter and wall thickness accuracy were explained according to the stress distribution. The results of the research can be applied to the design of the technical parameters in the forming process.

Abstract: The analysis model of coal pillar of a empty mine goaf in north of Shanxi province was constructed and the process of coal pillar from formation to weathering was simulated through the application of software of FLAC3D in this article. The stressstrain and the law of plasticity transformation of coal pillar from formation to weathering were analyzed and the long-term stability of coal pillar was forecasted. The result showed that the stability of coal pillar was bad for excessive excavated and weathering and the coal pillar will be broken easier for pressure and shear.

Abstract: The test-bench is used to simulate aircrafts posture in the air and it is for testing dynamic relief force when the fiber is paying off at high speed. In this paper, through analysis and contrast of the horizontal motion and the pitch motion, the scheme of movement is achieved. Based on the scheme of movement, the structural design and analysis on the stiffness and strength of key parts are done in the paper, the results shows that movement can be achieved.

Abstract: In this paper a batching machine for rubber production is presented which is widely used in rubber industry.This paper introduced the practical application and mechanical structure of batching machine then it elaborated the rotating component and the importance of shaft structure and parameters for its working qualities and working accuracy. Then it introduced the the spindles static and transient response based on ANSYS. It lays a foundation for optimal design.

Abstract: This paper presents the water landing dynamics simulation of a sounding rocket, obtaining dynamics characteristics of the interaction between the rocket payload module, the floatation airbag and the water. Using an explicit nonlinear dynamic finite element code, the model contains Lagrangian shell elements for rocket payload, membrane elements for the airbag and Eulerian elements for the water. The Fluid-Structure Interaction (FSI) technology is employed in the computation by transferring forces on nodes of coupling surfaces. In the paper, two landing attitudes are analyzed and compared. After analyzing dynamic response of airbag under different operating conditions, the minimum size is concluded. This dynamics simulation builds the foundation for the Engineering Model of the recovery system.

Abstract: In this paper, the semi-physical simulation technology is introduced with the design and implementation of a semi-physical simulation test bench. A certain low-speed marine diesel engine of high pressure common rail (HPCR) electronic control system is taken as the subject of the test bench. In order to retain the functional and structural features of the HPCR electronic control system, the essential components are in consistent with the target engine, and some auxiliary parts are simplified and reformed. Specially, a real-time simulation model is built based on the principles of Mean Value Engine Model and cylinder moving method, which captures the requirements of ECU, such as the crank angle, the exhaust valve stroke signal, the scavenging pressure and so on. Therefore a closed-loop control system is accomplished including a real-time controller deployed in the simulation model, ECU and the executing agency of HPCR system. Additionally a monitoring management system is developed for the test bench with the functions of acquiring signals, monitoring parameters, storing data, alarming and etc. Finally, some tests are finished in the test bench and through analyzing the experimental results, the test bench can perform the characteristics and functions of the HPCR electronic control system. The semi-physical simulation technology can be used for the functional verification and performance test of HPCR electronic control system for the low-speed marine diesel engine.

Abstract: Based on the differences aerodynamic characteristics between each sub-conductor of iced bundled conductors, a two-node cable element with three translational and one torsional degrees of freedom at each node is utilized to imitate the bundled conductor and the two-node space beam elements are used to simulated the spacers. Established nonlinear finite element equations of bundled conductors based on the principle of virtual work and solved these equations using Newmark-β method. Numerical example was employed to demonstrate the reliable and efficient of the presented method and program.