Applied Mechanics and Materials Vols. 16-19

Abstract: It has established the FEM model of nine horizontal roller straightening with original curvature for 60㎏/m heavy rail by using explicit dynamics software ANSYS/LS-DYNA in the paper, and it carried out the dynamic simulation process of the nine horizontal roller straightening, analyzed the stress changing rules of heavy rail in the seven deformation zones during the straightening process , even studied the value and distributive condition of residual stress after straightening, disclosed the mechanism of the residual stress in the heavy rail straightening process, and the paper is a guidance to improve heavy rail quality in straightening craft. It has the reference value to the design of heavy rail straightening machine and the formulation of the straightening regulations.

Abstract: Considering Iron & Steel Enterprise production operation situation, a multi-level mathematic model of capacity balancing and corresponding capacity balancing algorithm was proposed. The application of capacity balancing was discoursed on through making production capacity balancing in the branch factory level; production process level and machine level. And buffer pools were established to provide the possibility of capacity adjustment between various levels. With this method the difficulty of capacity calculation is solved, and provide a valid method for rapid establishment of production schedule.

Abstract: The quality of the green and the shaping efficiency are affected by the mold structure during the course of powder injection molding (PIM). Based on the numerical simulation, the mathematic model for the optimal design of the gating and runner system in PIM mould is constructed. The method is testified by the Moldflow software and the experiment. From the result, it is suggested that the clamp force and the shape cycle are clearly decreased, the green is densified and the samples’ density error of the green is decreased after the optimal design of the mold structure. Furthermore, the number of trial mold is reduced and the shape efficiency is improved.

Abstract: As a new technique integrating grinding and polishing, the technology of abrasive belt grinding is considered as a processing method with high quality, high efficiency, low consumption and wide range of application owing to its features of high processing efficiency, “cold” grinding, stable grinding speed, high precision and low costs. Taking aluminum alloy material as object of study and on the basis of the grinding technology of surface abrasive belt grinding machine, this paper carried out in-depth experimental study on the grinding mechanism of abrasive belt with aluminum alloy materials.

Abstract: Shape Distribution (3DSD) and Radius Angle Histogram (RAH) are useful methods for retrieving 3D model in mechanical engineering. Through these methods have advantages such as fast speeds and simple operations, the retrieval precision are not very high enough. To improve the retrieval precision, a new method named combined histograms which integrates the advantages of 3DSD and RAH is proposed. This method makes use of the information both of shape and surface of the models to be retrieved. In the retrieval process, the shape histogram and the radius angle histogram of the retrieved model are first extracted. Then, the combined histograms of the model are established by integrating the shape histogram and the radius angle histogram. To validate the proposed method, an experiment is given. The experiment results show that the proposed method has higher retrieval precision than that of 3DSD and RAH and is suitable for mechanical model design.

Abstract: Based on the STEP-NC basic theory, this paper uses the open module design method to construct a kind of CNC turning system based on STEP-NC in the integration environment of VC++6.0 and ST-Developer. The construction of system and processing of the programme and data are accomplished by using MFC class libraries, STIX and ROSE libraries, etc. This paper also studies the key technologies of the system, such as turning feature recognition, STEP-NC interpreter and tool-path generator. In the end, the STEP-NC turning simulative machining platform which can validate the correctness of STEP-NC program machining is constructed by using OpenGL technology.

Abstract: In general, production control of digital workshops is a complicated systematical engineering. Because of lacking the methods and means of acquiring the manufacturing data in real time, the traditional production control methods cannot satisfy the real production control requirement of digital workshops. In this paper, we put forward an intelligent control system for digital workshop production. The main contributions include three aspects: Firstly, we introduce and adopt Radio Frequency Identification (RFID) technology as a means to acquire the manufacturing information in real time produced by the bottom-level manufacturing devices. Secondly, we develop the wcPML (workshop control with Physical Markup Language) and utilize it to act as a media to realize the information visualized description and transmission between the top-level control systems and bottom-level manufacturing sites of workshops. Thirdly, we adopt Java Web technology and wireless LAN to build the infrostructure for the intelligent control system for workshop production. Some key enabling technologies for the intelligent control system also are presented and described following with some concluding remarks.

Abstract: Friction of two objects or inner friction of loose materials in vibration case can present different characteristics that are different from conventional conditions. The practice shows that vibration can reduce friction coefficient and friction force between two objects, lighten abrasion of objects, reduce energy consumption and increase greatly working efficiency. The mechanism of friction in vibration case was revealed in this paper. The Curve of vibration intensity to internal friction of soil was given. The investigation indicated that friction converts from static to sliding in vibration case. The internal friction is reduced with frequency increasing and there exists the optimal vibration intensity to make internal friction least. At last, nonlinear dynamic model of vibration friction system about compaction equipment was established and its resonance response was obtained.

Abstract: To effectively realize the collaboration in manufacturing processes for extended enterprises, this paper provided a service-driven networked collaborative manufacturing execution platform and its framework based upon the analysis of requirements for networked collaborative manufacturing, and the components of the platform were deeply studied. Furthermore, the collaborative operation processes were studied from three processes which include the process of manufacturing resource services modeling and register, the process of manufacturing task committing and manufacturing execution chain generation, and the process of manufacturing execution chain execution and monitoring. The study of this paper provided a feasible system and operation mode for the extended enterprises in manufacturing process collaboration.

Abstract: A rotary MRF (magnetorheological fluids) damper is introduced in tension control systems. An experimental tension control system is designed by using the MRF damper as tension control actuator. Control strategies of the tension control system are studied. A fuzzy-PID feedback controller for the tension control system is constructed and tested, where the variable parameters of the PID were modified by using the fuzzy inference rules. Experimental results indicate that the fuzzy-PID control strategy can be used in the tension control system to get better performance than the conventional PID control strategy.