Applied Mechanics and Materials Vol. 740

Abstract: This paper studies on the effects of different contents of redispersible emulsion powder and cellulose ether on mechanical properties of sulphoaluminate cement waterproof mortar, water absorption rate and impermeability, observes the microstructure of cement mortar by SEM and discusses the mechanism of polymer effects on properties of cement mortar. The results show that: as to the influence on strength, the two kinds of polymers may cause the decrease of early strength, but have no influence on the later strength; about water absorption rate, two polymers can significantly reduce the water absorption rate of sulphoaluminate cement mortar, and cellulose ether is slightly more effective than that of redispersible emulsion powder; as to the influence on impermeability, cellulose ether works far better than redispersible emulsion powder, especially when cellulose ether content reaches 1.5‰ and more, the impermeability pressure of sulphoaluminate cement mortar can reach above 2.2MPa.

Abstract: The influence of the naphthalene superplasticizer, aliphatic superplasticizer and water repellent on the properties of sulphoaluminate cement mortar such as strength and anti permeability was studied by orthogonal test method, and the microstructure of hydration products of hardened mortar was observed by X-Ray and SEM. The results showed that, adding amount of additive in sulphoaluminate cement, can improve mechanical properties of sulphoaluminate cement, and effectively improve waterproof performance and impermeability of mortar. When the water repellent admixture is 0.2%, the naphthalene superplasticizer 0.7%, aliphatic superplasticizer 1%, mortar impermeability is at its best, reaching 1.6MPa.

Abstract: Industrial alkali lignin (LG) was used as raw material and ionic liquid 1-butyl 3-methylimidazolium chloride ([BMIm]Cl) was used as solvent. Alkali lignin was dissolved into the [BMIm]Cl and modified as propyl ether lignin(HLG). Then the HLG modified lignin was used to synthesizing the lignin-based epoxy resin (LGEP) with epoxy chloropropane. The structure of LG, HLG and LGEP were characterized with FT-IR, the results indicated that the propyl group was introduced to the LG and the reaction activity was improved. The expoxy value analysis results showed that the optimum synthesis temperature was 80°C and the epoxy value was 0.218.

Abstract: The subject of this paper was the presentation of a holistic, fully-temperature-coupled FE model of inertia friction welding based on the modified friction law, which divided the friction welding process into beginning friction stage and steady equilibrium friction stage. At each of the stage Coulomb friction model and shear friction model were adopted respectively. The present FE model predicted the temperature of the welding joint as well as variation of friction torque and relative rotating velocity of the work-piece during the welding process. The evolution of friction torque and rotating velocity were compared with the experimental measurement. They showed a good agreement between them.

Abstract: A three-dimensional model for anode side of a passive direct methanol fuel cell with perforated flow field was developed to investigate the mass transfer in anode flow channels. The model simulated the transient two-phase flow in channels. With this model, the distribution of methanol concentration and carbon dioxide volume fraction in channels was presented. The variation of species on the central surface of flow channels was also gained. Simulation results show that the mass transfer in anode flow field of passive direct methonal fuel cells is affected by comprehensive effects of diffusion and convection. The results also indicate that the methanol transfer in channels is influenced by the carbon dioxide.

Abstract: In order to understand the operation of the water turbine generating by gravity .With the method of Linearization, equivalent and torque balance, this paper analysed, drove and calculated the water turbine’s rotational torque and speed theoretically ,and calculated by using examples according the motion characteristics of the turbine. By calculating, the factors of the water turbine’s capacity, the expression of the rotational torque and the turbine’s speed were obtained.

Abstract: Gear tooth modification such as lead crowning can reduce stress concentration at the edges of the gear teeth; therefore prolong the fatigue life of gears. A logarithmical lead profile was applied on spur gears and the surface coordinate equation of logarithmic crowned tooth for manufacturing was established. On the basis of the contact mechanics model, the deformation equation of compatibility and load equilibrium equation were solved with an iterative numerical algorithm, and the corresponding programs were developed in Matlab to calculate the distributions of contact stress and von Mises stress field inside the subsurface layer at any meshing position. The numerical results of some typical examples show that the level of stress concentration before modification changes with the engaging locations of the gear teeth, and so does the amount of logarithmic modification along the line of contact, which can completely eliminate the edge effects of tooth surface at every meshing position during the spur gear transmission process, and thus improves the fatigue resistance of gear teeth surfaces.

Abstract: The imported Electro-Discharge Texturing machine has widely used in domestic steel plants, this paper introduces the working principle and structure of SM Electro-Discharge Texturing generator produced by KLEINKNECHT Company. The remanufacturing of Electro-Discharge Texturing machine has considerable economic value, and we discuss the repair feasibility and detection principle through specific examples.

Abstract: This paper presents a creative profile of hybrid braking system (HBS) in order to resolve the collaboration between regenerative brake system (RBS) and ABS. Its mathematic model was set up and simulated in Matlab/Simhydraulic. The simulations show that it can collaborate with the control process of ABS and RBS and promote the efficiency of energy regeneration.

Abstract: CAM model of the fan blade based on UG NX software is introduced. The application of UG NX software in NC machining is stated. The machining techniques, tool path design and the simulation of the manufacturing process are analyzed in detail. Special postprocessor is developed for different NC systems. NC programs are generated by post processing files to effectively improve the efficiency of programming and machining