Applied Mechanics and Materials Vol. 775

Abstract: By using analytical and finite element analysis method, this paper analyzes the various factors on the impact of EDM surface roughness, puts forward a new mirror machining method of changing the order of the processing conditions and increasing the momentum of the swinging electrode in the process of EDM. Puts a measuring method for the surface quality with white light interferometer characterized by non-contact, high precision and vertical resolution in nanometer. Experiments show that in the non-mixed powder fluid, without replacing the electrodes and the processed work-piece is 45 # steel, the surface roughness of work-piece is 0.02 micro-meter, which meets the requirements for precision of the electrical discharge mirror machining.

Abstract: Multi-point forming process has been developed to shape the sheet metal with bidirectional curvature. However, the forming force usually climbs too high so that the dimension of the forming machine should be designed to meet it. To solve this problem, the multi-point incremental forming (MPIF) process was proposed in this paper. First, the principle of this new forming process was introduced. Then, the experimental device was designed. Next, the MPIF process was simulated by a finite element model. The forming effects including displacements, thickness, and curvatures were visualized and discussed in detail. It was found that there is no obvious thickness change during the forming process. The advantage of this forming process is that the shape of the sheet metals adaptable and controllable with small forming force.

Abstract: In the article the development of a simulation model of cutting slabs in a continuous casting machine is considered. Simulation modeling is used to optimize the sequence of the melts supplied to the continuous casting machine. The goal of optimization is to reduce the deviation between the estimated and actual numbers of slabs, because such deviations can lead to missed deadlines. The model of cutting slabs has been designed with the use of a models creation module of the metallurgical enterprise information system. The models creation module supports the simulation model creation and multi agent simulation. Agents in the developed model are intended to describe the cutting slabs algorithm used by technologists in the metallurgical production. As a result of experiments with the model the following solution has been found. The following sequence of melts should be supplied to the continuous casting machine: initially the melts from the usual quality steel, followed the melts from the high quality steel.

Abstract: The processing mechanism of electrical discharge machining (EDM) is complex and there are many factors affecting it, therefore the process parameter is very important for processing quality. This paper analyses the relationship between electric parameter and processing quality, then uses support vector machine (SVM) to predict the optimum electric parameter. The simulation result shows that the highest prediction accuracy is 96.10%, the lowest is 89.20%, average accuracy is 94.28%, indicating that the algorithm stability and generalization ability are outstanding. Further verified by experiment, the highest prediction accuracy can amount to 92.65%, the lowest is 81.5%, average accuracy is 89.38%, and electric parameter optimized by SVM can guarantee the expected processing effect better. The exploration in EDM intelligent machining will be convenient for operators to determine the most effective machining conditions.

Abstract: In this paper, a reinforce concrete inner supporting of tunnel working well is taken as the research object. Based on the result of field monitoring and numerical simulation, the change rules of axial force of inner-supporting are analyzed. By the method of field monitoring, the force condition of reinforced concrete inner-supporting can be understand. By the method of numerical simulation, the finite element model of reinforced concrete inner-supporting can be modeled by ABAQUS. The results show that, the error of measured values and design values is caused by the sensitivity of vibrating wire sensor, temperature and the shrinkage of concrete. This paper can provide a reference for similar measurement projects, whose measured values much larger than design values.

Abstract: Mega steel structure because of its own advantages is widely used in high-rise buildings, especially in super high-rise buildings. Mega frame structure, mega steel frame-prestressed composite bracing structure and mega steel frame-cable bracing structure were analyzed in this paper. The structure deformation and internal force of beam and column of structures were studied under load combination of Pretension and vertical loads, horizontal wind load. The results show that prestressed cable can improve the system stiffness, make the overall stiffness more uniform and control the deflection of mega beam and axial force of mega column effectively.

Abstract: In this study, the hydrodynamic characteristics of an X-braced-type jack-up leg with pile-soil foundation were investigated. Using the modified Morison equation and substructure method, wave excitation forces with effects of soil-structure interaction were calculated. The natural period and mode vector of the structure were obtained by using modal analysis. Newmark-beta time-integration method was used to predict the dynamic responses of the structure in the time domain. The maximum displacement and bending stress of the structure were analyzed under various soil conditions.

Abstract: With the demand on integrated construction of large scale LNG facilities in non-slide way zone at marine construction site, finite element analysis with parametric modeling technology (ANSYS-APDL) are conducted to simulate nonlinear relationship of basement and the state of foundation settlement at the construction stage. Structural analysis models are simplified from 3D architecture models of build order in building information modeling (BIM) system through MATLAB interface development. Unfavorable settlement effects are examined by detailed analysis cases studying. The prediction results can guide installation and temporary reinforcement measures of large scale structures.

Abstract: This study conducted a vibration table excitation test in order to evaluate performance of a tuned liquid damper (TLD), which was installed for vibration attenuation in a high-rise building, according to its installation direction. The TLD's base shear force and wave height characteristics changed according to excitation direction. When the excitation direction of the TLD was lower than 45 degrees, base shear force and wave height were the same as excitation direction at zero degree. However, when the excitation direction was 45 degrees or higher, base shear force and wave height were affected by excitation amplitude at 5mm or larger.

Abstract: Currently the settlement and deformation of factory building structure is monitored using total stations and other more conventional measuring instruments, it is difficult to reflect the health of the structure timely and accurately. In order to change the situation, we establish a set of system for real-time monitoring of deformation and safety warning. The system is formed of sensing layer, transport layer and application layer. Sensing layer is composed of static force level and biaxial inclinometer. The system can be used in dynamic real-time factory structure safety monitoring, also applied to other similar structural monitoring. This paper will study the system components and principle, early warning systems grading, calculation of real-time deformation of roof frame, laboratory test scheme and verification. Experiments showed that the system is suitable for the actual factory structure monitoring, while the choice of static force level and biaxial inclinometer of precision to meet the requirements.