Applied Mechanics and Materials Vol. 473

Abstract: The article mainly provides an overview of air cushion belt conveyor, and describes design of air chamber, as an important part of the air cushion belt conveyor. The article introduces reasonable structure design of the air chamber from aspect of practical experience. In addition, the article researches air pressure design and calculation of air chamber, design and calculation of air volume of the air chamber, as well as power determination and design calculation on fan. The article designs and calculates per opening area of the air chamber as well as opening method of the chute depending on air pressure and air volume, and simultaneously analyzes formation influence factors and features of air pad in the chute. And finally, the article proposes reference conclusion and suggestions on the basis of research on the design of the air chamber.

Abstract: Shear wave splitting technology plays important role in detecting fractures. Picking up the calculation window is necessary in the shear wave splitting technology and plays a decisive role in the accuracy and precision detecting the orientation of fractures and fracture intensity. Conventionally, the calculation window for shear wave splitting is manually set, which is both laborious and subjective. Thus providing an mechanical automated method of picking up the calculation window is very meaningful.

Abstract: The robot adopts a mobile platform designed for post-disaster environment information collection which can deform passively .The robot deforms when the robot is cross obstacles, the robot will reset after through the obstacles. Mobile platform's reset ability is determined by the reset parameters, reset parameters include spring stiffness, initial length, and installation position. The relationship between ground constraints and reset spring is established by static analysis; optimization of reset spring parameters is conducted by using the least energy consumption in the attitude changing as a target in Matlab. The optimized parameters reduce the energy cost effectively in the condition of satisfying the movement requirements, which verifies the correctness of the optimization results.

Abstract: Crawler transporter is an emerging material handling vehicle for construction of transmission networks in mountainous areas, featuring high efficiency and safety. It consists of a crawler chassis, a remote control system, front and rear carrying gantries which can rise/lower and make left/right turns for smooth running in special terrains, a ginpole for handling of tower, a skip which, together with the carrying gantries, is capable of handling different kinds of materials, and a self-recovery winch. This paper also introduces a series of test methods to ensure safety during handling of material using this type of transporter.

Abstract: In recent years, ultra-urban road overpass vehicle impact beam incident after another. High beam impact of vehicles on the overpass bridge safety impact has become another important issue. High trucks at home and abroad on the curve of reinforced concrete beam bridge working effect of the impact is still insufficient. Based on high-precision linear dynamic finite element simulation analysis, research under the action of high vehicle collision, reinforced concrete curved girder Bridges of local damage effect and the overall distortion performance. The results showed that: high vehicles on the bridge superstructure imposed impact impulse and punching power led bridge superstructure is hitting zone produce local cracks. Damage caused by different impact velocity varied.

Abstract: We have proposed a new cold processing method to form a partial diameter-enlargement part in a hollow shaft. Using the processing method, the diameter-enlargement part with a large deformation is formed easily by applying compressive stress at yield stress level and cyclic torsional stress on two ends of specimen. In the present paper, processing experiments were conducted using the processing machine developed originally based on the processing principle, and deformation behaviors on the diameter-enlargement part were measured. In addition, the simulation analysis method in the processing was developed by the finite element method (FEM), the behaviors of stress and strain on processed part were analyzed, and deformation mechanism was investigated. It is clarified that the processing conditions affect the deformation behaviors base on the experiments and analysis.

Abstract: This paper proposes a new near-net-shape working method to partially enlarge and control shaft's cross section through a metal mold. This study investigates the changes in the sectional area of shafts during the processing under various processing conditions, and evaluates the changes with a filling ratio. We introduce the processing method and the processing conditions, and then we report the results of processing experiments. Lastly, we clarify that processing conditions influence on the geometry of the processed part.

Abstract: The aim was to analyze failure mechanism of electromagnetic relay caused by mechanical impact. The principle of electromagnetic relays was studied and the effect of mechanical impact on electromagnetic relays was analyzed in this paper. Based on the established magnetic circuit model, the relationship of the magnetic field strength, the electromagnetic attraction and the impact damage degree was studied. Then, the damage intensity of mechanical impact on magnetic circuit was decided. Afterwards, the structure of electromagnetic relays was improved, and the mechanical impact simulation was studied by ANSYS. The results show that the uncontrollability of electromagnetic relay is mainly caused by air gap, which is aroused by mechanical impact; in addition, the size of air gap is inversely proportional to electromagnetic attraction force. Moreover, the improved structure of relays can increase impact resistance and broaden the scope of engineering application of electromagnetic relay.

Abstract: According to " leader missiles - attack missiles " formation model, the measurement model of missile in formation flight VisNav is derived. The observability analysis of missile VisNav is shown for cases involving three vector observations, the conclusion is that at least three characteristic points are visible to insure visual navigation systems to work properly. The least square algorithm is applied to process the data of VisNav to estimate the relative attitude and position. The results of simulation show that the accuracy of least square algorithm would be influenced by the relative position of missile in formation flight mechanics.