Applied Mechanics and Materials Vols. 94-96

Abstract: Abstract. For the bridge temporary structures, the present mainstream calculation method is based on dialog box data entry or command flow technology, in view of their insurmountable defects, a new calculation method based on graphic flow technology is presented and implemented in this paper. The comprehensive solving process of bridge temporary structure is planed and decomposed into a series of easily implemented sub-steps, their calculation models can be described by a group of independent and cooperative function graphic object types, in which global or local structure features, construction specifications, dynamics characteristics, engineering experience, intention expression, expert solving plan and other comprehensive application knowledge can be expressed easily. By creating, operating and deducting these function graphic objects, the solving sub-steps can be easily implemented. As a result , the comprehensive solving process for bridge temporary structure based on engineering features can be realized , and the simplification and high efficiency of solving process are achieved. The new method is also can be applied to other complex engineering structure fields, development practice shows its broad application prospect and development space.

Abstract: Considering the requirements of the high accuracy, high reliability and real-time capability for the aircraft geomagnetic correlation matching algorithm, the similarity core function, geomagnetic properties and search methods will be processed synthetically in this paper. The correlation variance is introduced as the similarity core function, the feature normalization of the geomagnetic field is introduced as the matching parameters and the differential evolution algorithm is introduced for reducing the running time. The experiments have been done in the laboratory based on the actual measured geomagnetic field data, its results show that: the matching probability and accuracy of the new algorithm are better than the traditional one on the whole and the average running time is shortened from 7～11s to 1～2s.

Abstract: Efficiency and accuracy of forward problem are important in structural analysis. A real-time algorithm, called inversion reduced-basis method (IRBM), is applied to analyze a dynamic problem. A spring-mass system is taken as an example, results computed from finite element method and IRBM are obtained. Comparing results from the two methods, IRBM can get high-precision results quickly.

Abstract: Based on the optimal velocity model, an extended optimal velocity model is proposed to simulate the movement characteristics of multi-types pedestrian queue by considering the differences among pedestrians (e.g., the differences in age and sex, etc.) and the asymmetric interaction. For the random distribution of pedestrian queue, the evolution rules of pedestrian movement and the formation mechanism of space-time pattern under two different boundary conditions are investigated. The numerical simulations show that the model can better describe the space-time distribution of pedestrian movement from microcosmic viewpoint and reproduce such important phenomena as the formation, dispersion of jams and multi-clusters movements.

Abstract: In this paper，the model of dynamic simulation about the truck crane’s luffering mechanism has been established. The optimal expression of the driving function of amplitude cylinder for the constant velocity hoisting of crane boom has also been acquired through the method of dynamic reverse algorithm by using the adams. It can provide the reliable basis for the power control of the luffing mechanism of truck crane. The results come from the simulation in all working condition of various operating of the luffing mechanism of truck crane show that the above method is effective and has a certain application value.

Abstract: Strengthening the practice training is a primary means to ensure the safety in coal production. To solve the limitation of traditional work training method in coal industry, a Simulation System of Coal-Mine Work Training (SSCMT) is developed based on VIRTOOLS. With the system, the trainees can complete various operating training and study various operating regulations in a virtual coal-mine working environment. The paper makes a detailed explanation of the design and development of SSCMT from the following aspects: system functions, creating a virtual environment, training evaluation, system optimization. The realistic application demonstrates that the SSCMT system has brought good results in reduction of training cost, stimulation of learning interest, and improvement of training quality.

Abstract: A multi-degree-of-freedom (MDOF) vibration isolation system (VIS) model is established with finite element method. And the numerical simulation results of the model under axisymmetric load in a good fit to the simplified model results. The model dynamics behavior under any load also was calculated, and it makes a further analysis for the vibration isolation effect of the model.

Abstract: Natural Zoning for Highways is the important basis of highway network planning and establishment of related specifications and standards. Determination method for influence coefficients of comprehensive zoning indices analysis model is the key to increase quantization degree of comprehensive zoning indices analysis. Based on the theories of fuzzy clustering and rough set, this paper put forward the method to reasonably determine the influence coefficients of single elements and calibrate the analysis model of comprehensive zoning indices through analyzing the calculation elements data by random sampling method. Highway surface configuration index(HSCI) was analyzed with this method. The map of HSCI reflects the influence degree of surface configuration on highway engineering in different regions in China correctly. Analysis result shows that the method improves the quantization degree of comprehensive zoning indices analysis.

Abstract: There is large fires risk and difficult evacuation in underground buildings, so it is necessary to study the development of fire and evacuation procedure in underground building. In this paper, a large underground banquet hall was chosen as an example, evacuation safety in the hall was analyzed by numerical simulation. First of all, fire model and two fire scenes were set up by using the software Fire Dynamics Simulator. Then the process of fire spread was reappeared by numerical simulation, and evacuation process was simulated by using the software PathFinderTM. By comparison with both result, it was proved that there is safe personnel evacuation in the case of effective fire-fighting facilities. According to the simulation results, reasonable recommendations about fire safety of the large banquet hall was proposed. The research will contribute to fire prevention and architecture design.

Abstract: The buckling of no-way double-layer portal frame that column is fixed is simulated by using ANSYS. Through analyzing the portal frame subjected to different loads on the roof of the structure that are uniform load, trapezoidal load and triangular load, the critical buckling load of the double-layer portal frame and buckling mode are obtained. The regular between the critical buckling load and the form of the load on the roof can be acquired by the analysis of the results, which can be used as a reference for engineering application.