Advanced Materials Research Vols. 317-319

Abstract: The purpose of the study is to measure the maximum static friction and dynamic friction in the actuation process of pneumatic cylinder after TiO2 nanoparticles are added to grease. The study makes an innovative design of a new measuring equipment of friction force, which can measure the friction force between the piston seal in pneumatic cylinder and the cylinder bore. The friction force of pneumatic cylinder bore directly affects the output dynamic property of pneumatic cylinder motion. Friction force measuring system can measure the change of friction force of pneumatic cylinder bore under the condition with different operating speeds, and can analyze the relationship between friction force of pneumatic cylinder and output dynamic property of pneumatic cylinder. Such a friction force measuring equipment takes pneumatic cylinder as an output of motive force to drive the measurement of pneumatic cylinder, and uses load cell and draw-line encoder to measure the friction force of pneumatic cylinder bore and the motion speed. In the experiment, the friction forces of pneumatic cylinder given with oil and without oil are measured respectively, achieving the friction force property of pneumatic cylinder bore when being lubricated by nanogrease added with nanoparticles of different weight percentages (wt.%). The experimental results show that adding TiO2 nanoparticles to grease can effectively decrease the friction force produced in the actuation process of pneumatic cylinder.

Abstract: The symmetric implosion of the pellet is very important in an inertial confinement fusion (ICF) system. The evaluation of symmetric distribution on the ICF pellet is time and memory consuming, especially when the elements of cylindrical hohlraums are iteratively subdivided. A novel compressive sensing (CS) based approach is presented in this paper to accurately valuate the distribution symmetry with much less computation. The core idea is that, the thermal radiation distribution is transformed in the spherical harmonic field, and the sparsity of spherical harmonics is accurately evaluated through CS approach. Finally, experiments are demonstrated to show higher efficiency of the proposed approach.

Abstract: According to the development status of underground load-haul-dump vehicle (LHD) development, a virtual-prototyping oriented key research and development system of LHD is proposed. Based on the driven oriented and top-down design concept of virtual-prototyping, combining the overall performance design, multi-body system dynamics oriented characteristic analysis and simulation, machine assembly, main parameters verification and sub-system of LHD design, the new innovation design development system for LHD development is formed. A case study of a three cubic LHD design process is given, considering the multi-body dynamics oriented simulation of LHD overall performance ,the structure strength analysis and fatigue analysis of key components, mechanism optimization design and dynamic kinematics analysis of working device, stability, ergonomics and ROPS/FOPS (Roll-Over Protection System / Fall-Over Protection System) of driving cab, the satisfied design results is finally obtained.

Abstract: Abstract: For the marine engineering construction of Sinochem Quanzhou Petrochemical Co., Ltd. the pollution of port sewage, wastewater, rainwater and sewage vessels after inspection and testing were quantified. And the air pollution caused by ship emissions and Handling loss was determined. The sources and concentrations of major pollutants were summarized in the study, and the measures to be taken were planned.

Abstract: Compared to conventional transmission layouts, Active continuously variable transmission (CVT) provides smoother gear shifting and gear ratio in smaller increments, and is, therefore, more accommodating the needs of both the driver and passengers. A few notable improvements are enhanced passenger comfort, higher transmission efficiency, and improved acceleration. Incorporating all of the above qualities has become a major developmental focus for the automotive industry, and the potential for improvement warrants further investigation. A CVT controls the gear ratio by changing the diameters of the primary (input) and the secondary (output) pulleys by adjusting the hydraulic pressure applied to each using valves. Hydraulic pressure in the channel is developed using a basic pump connected to the input shaft. Excess pressure produced at higher speed is wasted. This study aims to minimize this hydraulic pressure without affecting the transmission’s performance, in order to conserve energy. A user interface was set up and the CVT’s torque converter was modified such that the inner and outer shafts could be operated independently, allowing for full control of hydraulic pressure .This experiment successfully achieved, via a custom LabVIEW program, its goal of controlling the gear ratio between the primary and secondary pulleys whilst operating at lower pressures to those specified by the manufacturer. This proves that it is possible to fully control the CVT whilst operating at a reduced hydraulic pressure.

Abstract: Laser technology has been applied in more and more areas of research. With its fast growth, faster and cheaper solution can be found in different industries. In this paper we present two applications of laser on LED and semi-conductor manufacturing. A new approach facilitated by laser micromachining for improving LED efficiency is introduced first. This is through change of stacking structure and the precision of up-to-date UV 355nm laser technology. The illumination area is increased due to the smaller connecting area (drilling size). Another work is the improving of leakage current of TiO2 film as dielectrics. Through the irradiation of 532nm DPSS laser the refractive index increases and the current leakage is reduced.

Abstract: A temperature monitoring system for mechanical press’s bearing is presented. As multipoints of the cranks need to be monitored, the system is based on RS485 BUS, which is a distributed, real-time and reliable temperature monitoring net. It consists of the temperature monitoring sub module and the master module. The sub module gets temperature data via thermocouple and MAX6675. The master module controls the whole system with an ARM IC. The system can judge whether the temperature of bearing has exceed the limited value or the temperature is rising too fast, and send alarm signal to stop the press in those cases. Configuring this temperature monitoring system to the large or medium scale mechanical press can avoid the accident like bearing-burnt effectively.

Abstract: Adding fly ash to recycled concrete with super-substitute technique, comparing the 28d strength of fly ash recycled concrete(FARC) with the 28d strength of ordinary recycled concrete(ORC), the compressive strength of fly ash recycled concrete slightly decreased with the increase of the fly ash and the admixture of renewable aggregate. Along with the increase of mixing amount of the air entraining and water-reducing agent, the compressive strength of fly ash recycled concrete tends to reduce. The order of the factors that affect the chloride ion diffusion coefficient of recycled concrete is fly ash admixture→mixing amount of the air entraining and water-reducing agent→admixture of recycled coarse aggregate→polypropylene fibre admixture, which provides a basis for the application of recycled concrete engineering in the environment which is affected by chlorine salt in the north frigid area .

Abstract: A full transient elastohydrodynamic lubrication(EHL) solution of involute spur gears is obtained under impact load based on the multi-grid (MG) method for solving the pressures, the multi-level multi-integration (MLMI) approach for evaluating the elastic deformations, which takes into account the variation of equivalent curvature , entertainment velocity and load on time along the line of action, the gear tooth surface is assumed to be smooth. The influences of impact load spectrum and the approach impact load when the teeth come into action on the EHL pressure and film thickness are analyzed in the paper. The results show that the approach impact load can strongly influence the approach point maximum pressure and minimum film thickness. The impact load can lead to instantaneous lubrication film deterioration between contact teeth of involute spur gears. The maximum pressure and the minimum film thickness all occur in the vicinity of approach point immediately after the impact load was feed. The approach impact load is seriously harmful to the gear lubrication.

Abstract: Petri nets are employed to model flexible manufacturing systems (FMSs). However, the system deadlocked are possible happened. The conventional deadlock prevention policies are always to forbid the system entering the deadlock by using the control places. To obtain a live system, some dead markings must be sacrificed in the traditional policies. Therefore, the original reachability states of the original model can not be conserved. However, this paper is able to maintain all the reachability states of the original net and guaranty the control system live. Under our control policy, all number of reachability states of the original net will be preserved. Finally, two examples are performed that can reach the maximal permissiveness for FMSs using Petri net models (PNMs).