Applied Mechanics and Materials Vols. 246-247

Abstract: Structure failure risk caused by air wave on high-speed vehicle airtight body is considered and it’s necessary to bring out the conception of airtight fatigue strength and start related research. There is a review of airwave and structure fields, including air dynamic of rail-vehicle, load carrying structure and strength test standard. Nowadays, the direction of air dynamic research is focused on how to reduce air wave pressure and enhance stability of running vehicle; the structure study is focused on static and transient load carrying response of wheels, bogie and so on structures under traction running and weight load. It’s not been fully researched that how the airtight structure vehicles response when carrying air-dynamic in long run. Based on current research, an analysis line is brought out which contains simulation and experiment, fluid-structure interaction study and structure fatigue assessment calculation

Abstract: In shipbuilding, the storage yard is used to store assembly blocks of ships. It is an essential part of the shipbuilding system.The storage yard management contains:determining the exact storage locations for the arriving blocks, and determining the storing or retrieving route for each block. Aheuristic approach was proposedto maximize the space utilization and minimize the obstructive. Based on the approach, a storage yard management systemwas built.The system is used by the planners and got positive effect.

Abstract: Take conical cylinder spherical swashplate type axial piston pump as research object, the calculation method limitation of slipper shoe mounting hole which located in mounting plate is analyzed. First of all ,the motion characteristics and the trace of slipper shoe is derived, then,based on above results, the sipper shoe mounting hole size current calculation methods in engineering and it’s limitations is analyzed,the conclusion is that: current design methods is parameter averaging method and also is an approximate method, in theory is not accurate and in engineering is unreasonable. In order to deign the slipper shoe mounting hole accurately, this paper recommends the most reasonable method is using slipper movement envelope to determine its shape and size.

Abstract: In the mix burning technology of burners, the reasonable air-fuel ratio is the foundation of fully burning. At the scene, as the flow rate of associated gas changes, the optimum air-fuel ratio decided in the flow rate of associated gas instability, it become the key to ensure full combustion of mixed fuel. In this paper, the flow rate of associated gas is divided into several flow intervals, with test data and theoretic, the optimum air-fuel ratio is obtained, corresponding to the flow rate of associated gas in the mix burning technology. The instances show that if the mix burring process is controlled based on air-fuel ratio obtained, the flames are stable and it is also energy-conserving. In addition the emissions are lower than the national standard GB/T 19839-2005 rules.

Abstract: The concrete pump truck’s boom system of 5 booms is taken as the research object in this paper. Combined with finite element theory and multi-body dynamics theory, a rigid-flexible coupling model of concrete pump truck’s boom system is established by modal synthesis method. With the measured displacement-time curve of turntable as the excitation, the booms’ pumping process in horizontal mode is simulated by the dynamic simulation software ADAMS. Through the field experiment results, the rationality of the modal is verified. It provides an effective method for dynamics analysis and structure improve of the concrete pump truck’s boom system.

Abstract: Although intelligent NC programming technology has made some progress, the efficiency and practicability were not high. For this reason, we presented the intelligent NC programming pattern based on process scheme (PS). In this pattern, some models and the rules were mainly proposed. Firstly, by analyzing the machining characteristic of aircraft structural parts, we established the tree model of PS and the constructing rules. Secondly, we constructed the extended generalized pocket model by slicing recognition to create the machining volume model (MVM). Thirdly, the machining chain model was put forward based on the PS and MVM. Finally, the developed pattern and model have been applied in the intelligent NC programming system of aircraft structural parts and are validated with high practicability and efficiency through a case study.

Abstract: A kind of paper-separation mechanism of packing machine for medicine was introduced in this paper. A new parametric equation of cam profile is designed on the basis of the kinematics rules of suction nozzle. Model building of cams are accomplished by using software SolidWorks.

Abstract: This thesis study on algorithms of auto-generating engineering geology histogram, For example: the hierarchy model of drilling histogram, rendering algorithm of lithologic columnar and the rendering algorithm column separator. MapGIS was secondary exploitation platformand , and Borland C++ Builder 6.0 was programming language. Through called MapGIS’ secondary exploitation components directly and used algorithms mentioned in this paper, engineering geology histograms was auto-generated. Being validated by practical engineering geology data, the software system not only runs steadily and generates plot rapidly, but also the result is exact, generating histograms is slinky and concordant.

Abstract: In recoil mechanisms applications the response time is an important characteristic for Magnetorheological (MR) fluid dampers, since the recoil cycle is very fast. Method for experimental testing the response time of MR dampers subjected to impact loading was promoted and impact tests were done. Since the viscose damping force of MR dampers is only related to the recoil velocity, which can not be controlled by the operating current, only the controllable damping force response to the input voltage was evaluated, and the viscose damping force were removed by the MR damper’s model. Two factors that may have effect on the response of MR dampers were considered the response of the electromagnetic circuit current of MR damper coils, and the response characteristic of MR fluid material. PI control algorithm was used to shorten the circuit current response. The results indicated that, compared with the much shorter delay of MR fluid, the driving circuit response has more significant effect on the MR dampers’ response time. What’s more, it was also verified that, it is feasible to improve the MR dampers’ response time subjected to impact loading by modifying the electromagnetic circuit through good control algorithms.

Abstract: For the multi-channel data acquisition system, crosstalk significantly affects the sample accuracy. Through analyzing the mode of multiplexer and the sampling timing sequence, we demonstrated that crosstalk effect mainly results from the switch of multiplexer for the low- frequency multi-channel data acquisition system. A new crosstalk testing method based on phase-shift rectangular waveform for the multi-channel data acquisition system was proposed. The phase-shift rectangular waveform was designed. Experiments were conducted to test crosstalk effect of the multi-channel data acquisition system. The experimental results were demonstrated that the proposed approach based on the phase-shift rectangular waveform exhibits a distinct feature in effective channel crosstalk testing, compared with waveforms of other types. Thus, the proposed method is effective to detect crosstalk of the multi-channel data acquisition system.