Applied Mechanics and Materials Vols. 713-715

Abstract: The thermal distortion of friction pair will be produced in high line speed frictioning. For solving interaction theory from this problem, thermal distortion micro-bulges model of two interaction friction surfaces is built by ways of micro-interaction dynamics, and equations of contact forces of micro-bulges are obtained. By using mathematic statistics and normalization, equations of macro-normal and tangential contact forces are obtained, and relation between friction coefficient and micro-parameters is found. Contact forces and friction coefficient characteristics expressed by parameters of dimensionless clearance and curvature are simulated. The results show that the interaction theory is important in deeper understanding friction and wear theory in high line speed running, and offers reliable proof for future finer structure design of friction pair and model design of clutch.

Abstract: Damping ditch is an important method to reduce blasting vibration effects. In order to investigate rules of damping trench on blasting vibration, blasting experiments of damping channel were conducted in an actual project. Meanwhile, blasting seismic waves were measured with analysis of datum. Results showed that blasting vibration intensity was distinctly reduced by using damping ditch; the spectrum of seismic waves was changed to decentralize the energy to dampen blasting vibration.

Abstract: The thermal effect caused by absorbing inclusion irradiated by pulse laser is affected by size of inclusions, pulse duration, repetition interval and number of pulse laser. The temperature both in the center of inclusion and the interface between inclusion and dielectric increases firstly with the increase of the size of inclusion, then trends to a constant value when the size is over the critical radius. Pulse duration and repetition interval of pulse change the energy acumulation in inclusion then have influence on the peak temperature in the center and interface. The temperature fluctuates periodically but the overall assumes the trend of increase.

Abstract: The dynamic mathematical model of FCCU reactor was established. Reaction kinetics uses five parameter lumped model, with components emulated by similar hydrocarbons. Simulation system was built to simulate normal conditions, and the effect of some abnormal conditions on charred tank’s exit oxygen content, charred tank’s temperature (not cooled), charred tank’s temperature (cooled) were studied. Because the abnormal condition is the combustion of regenerator’s dilute phase’s extremity, this paper used the amount of carbon monoxide’s combustion to simulate this abnormal condition.With the variation of the charred tank’s exported oxygen content or temperature reflects the degree of dilute phase’s combustion. The results show that the dynamic simulation of the system can accurately simulate the cracking reactor abnormal condition.

Abstract: Hydrogen-gasoline blends is an effective way to improving the performance of spark ignition engine at stoichiometric and lean conditions. Spark timing is one of the important parameters affect the engine performance. This paper investigated the effect of spark timing on performance of a hydrogen-gasoline engine. A four cylinder, gasoline direct injection engine was modified to be a gasoline port injection, hydrogen direct injection engine. The hydrogen energy fraction was set as 0% and 30%. For a specified hydrogen addition, the engine was operated at four excess air ratios of 0.8, 1.0, 1.2 and 1.5. Under the specified excess air ratio condition, the spark timing was varied from 4 to 19°CA before top dead center (BTDC) with an interval of 3°CA. The test result showed that the indicated mean effective pressure (IMEP) climb up and then decline with the increase of spark advance. For hydrogen-gasoline engine, the optimum spark timing for the max IMEP was retarded at a specified excess air ratio. The max thermal efficiency appeared at the optimum spark timing.

Abstract: When hydrogen is added to a gasoline fueled spark ignition engine the lean limit of the engine can be extended. Lean burn engines are inherently more efficient and have the potential for significantly lower NOx emissions. Thus, the purpose of this paper is to investigate the effect of hydrogen addition to gasoline-air mixture on the performance and exhaust emission characteristics of a spark ignition engine. Six excess air ratios are used ranging from 0.8 to 1.5. The amount of hydrogen added is 18.5% and 30% by energy fraction. The test engine is operated at 1500 rpm. From the experimental observations, the effect of hydrogen addition on thermal efficiency, specific fuel consumption, cyclic variations of the indicated mean effective pressure (IMEP), and emissions of CO, unburned hydrocarbons and NOx are analyzed.

Abstract: Turbocharger assembly process has two assembly dimension chain, the assembly dimension chain between the shell, and the assembly dimension chain of the parts of the impeller shaft. Between them are interrelated, eventually formed with the gap between the impeller and the casing. The impeller is rotationed by exhaust gas flowed through the impeller chamber through the nozzle ring promote. It will result in the loss of the exhaust gas flow if the fit clearance between the impeller and the casing is greater than the design value, the impeller speed can not meet the design requirements Resulting in turbocharger boost the value below standard,and the boost the value of turbocharger can not meet the requirements

Abstract: Based on the existing fiber reinforced polymer (FRP) durability research, considering the difference different regions, a multi-factor durability evaluation model for structural reinforcement FRP has been established. Firstly, combined with the result of rapid aging experiments, a benchmark aging model of a single factor is built. Secondly, classifying the various factors according to different geographical environments, and taking the difference between various environmental factors and test conditions into count, the benchmark aging model is revised. Thirdly, it is to make sure the main environmental factors, determine the effect weight of various factors in different areas and a coupling aging model is established through the coupled superposed. Finally, the carbon fiber reinforced polymer (CFRP) coupling aging model is obtained and compared with actual environmental in A area as an example to validate the model. The result that it can ascertain both trends are consistent and be used to guide durable design.

Abstract: This article propose a new design pattern with combining engineering science and "user-centered design". For the purpose of finding a new pattern to design a new product to meet the user needs, and to adapt the update rate of products under large industrial environments. This article through summarize and analyze the shortcoming of “user-centered” design pattern, and point out the significance of engineering science in product design. Finally the new pattern with combining engineering science and “user-centered design” has been proposed. Using this pattern to redesign the traditional pump, the result show that the new pump is efficient and fit for using than before, so the new design pattern could make sure the products meet the user needs and adapt the update rate of products.

Abstract: Cooling is very important in the process of hot stamping process of a link, directly affect the mechanical properties and service life of the forming parts. Mold cooling system is effective and reasonable, therefore, is the important indicators of the hot stamping process performance. This paper deeply analyzes the hot stamping process and heat transfer theory, summarizes the main factors affecting mold cooling system performance. At the same time, the fluid analysis software FLUENT is adopted to U artifacts a numerical simulation of the hot stamping process analysis of mold during the cooling process, the work piece temperature field change, for the hot stamping mold cooling system design to provide theoretical reference.