Applied Mechanics and Materials Vol. 441

Abstract: The polarization curves of repairing layer of cold welding and iron-based material were measured by linear sweep voltammetry technology (LSV) in perchlorate or chromate solution, meanwhile, the range of maintaining passivity potential and current was obtained according to the polarization curves. The results showed that the passivation of cold welding and cladding iron-based material was becoming obvious with the increasing perchlorate or chromate concentration. Laser cladding iron-based material had better property of passivation than the cold welding material, while its corrosion property was inferior to the cold welding.

Abstract: Proposed a mixed circuit fault diagnosis method based on support vector machines for the lower rate of mixed circuit fault diagnosis and diagnosis slower. The basic idea is the use of wavelet decomposition to extract the dynamic current of the mixed circuit, and re-integration of the SVM fault diagnosis. By PSPICE software and MATLAB software simulation analysis of the mixed circuit, simulation results show that this method can improve the convergence speed of the BP neural network, and can make the BP neural network is not easy to fall into local minimum value, so that the network has a better pattern recognition capability. This laid the foundation for the completion of a more rapid and accurate mixed circuit fault diagnosis.

Abstract: A method using infrared thermal images and weights-direct-determination neural network (WDDNN) to identify the zero resistance insulators on-site is presented. The basic procedures were as follows: the infrared thermal image were denoised, intensified, segmented, and a rectangular which was regarded as object was intercepted in the insulators chain; in view of the relationship between gray value of infrared thermal images and temperature of object surface, four parameters which stand for standard deviation, absolute deviation, quartiles and range of gray value, were extracted directly; these four parameters were used as the input of WDDNN to train the model, which could be used identifing the zero resistance insulators after being trained. This method can effectively avoid the interference of transmission lines, and can meet the real-time require when identifying on-site. Experimental results verify the feasibility and effectiveness of this method.

Abstract: Combining the site relocation project of New Era Cement Co. Ltd, the early temperature and strain monitoring and numerical simulation are done on the cement vertical mills mass concrete equipment foundation sizing 15.6m×15.6m×5m, thus, the early trends and rules of mass concrete about temperature and strain are analyzed. Prevent temperature cracks due to temperature strain in mass concrete, therefore, ensure the construction quality of mass concrete.

Abstract: Gear and rack drilling rig is currently the advanced model of oil rig, which rely on the gear meshing with the rack, driven top drive up and down movement. The equivalent model of derrick and lifting system were established, and the Lagrange equation was built by using the method of energy. The dynamic simulation analysis was carried out by using ADAMS automatic analysis of software. Research result show that analysis lifting system of gear and rack drilling rig, the flexibility of the derrick has minimal effect on the acceleration in the bit of vertical direction; Consider the drill string movement suffered damping effect, drilling bit vibration is obvious in the initial time of drilling, but does not affect the speed of drilling and gradually stabilized.

Abstract: Military Scenario Definition Language (MSDL) is intended to provide a standard mechanism for loading Military Scenarios independent of the applications. Some customized scenario specifications lack scalability and interoperability with Command and Control (C2) applications. And how to integrate MSDL with simulation models still needs further implementation. This paper extended and modified MSDL to propose a feasible simulation scenario specification based on our existed CGF (Computer Generated Force) model system. A CGF-SDP (Scenario Development tool) was also developed to facilitate generating course of action (COA) of a military scenario graphically based on a GIS system. A simulation scenario was generated by this editor and it was effectively used in a combat simulation system’s execution process.

Abstract: A universal joint fork is one of the key parts of the automotive and tractor drive shaft system, which needs high requirements in dimensional accuracy and product quality. In this study, the numerical simulation analysis of closed-die forging of the universal joint fork was carried out using the rigid-visco-plastic finite element model. In view of formation, heat transfer and heating generation coupled, the variation rules of forming load, stress field and strain field were obtained. The numerical simulation results show that good process parameters conditions can effectively control forming load, enhance metal flow and improve die life.

Abstract: Based on the theory research and virtual prototype technology, the dynamics characteristics of drum washing machine vibration isolation system is studied and analyzed. According to the Lagrange method, the dynamics equations and motion differential equations of drum washing machine vibration isolation system is established. Through the establishment of rigid parameterized virtual prototype model of the vibration system, dynamics simulation analysis is accomplished based on ADAMS, the kinematics characteristics and mechanical characteristics are obtained.

Abstract: This paper used LS-DYNA simulation software to simulate rock bolt breaking position, displacements at different locations and the plastic deformation under dynamic load. Major drew the following conclusions: plastic deformation of the bolt away from breaks 600mm is only 1/20 compared with breaks; deformation of the rock bolt increased as the distance away from dynamic load applied position reduced, rock bolt deformation under dynamic load has a local effect; rock bolt deformation under dynamic load and rock bolt deformation under static load had essentially different.

Abstract: During the traditional traffic accident handling, the position information of vehicle and pedestrian is only considered and the information of pedestrian injury is often neglected. In order to improve the reliability of pedestrian-vehicle accident detection, this paper proposes a car accident detection method based on integrated information of vehicle position and pedestrian injury. According to a real vehicle-pedestrian accident, it is proved the proposed method is more effective on accident detection than traditional method.