Advanced Materials Research Vols. 1030-1032

Abstract: Rod matrix is effectively applied to separate fine weakly magnetic particles in pulsating high gradient magnetic separation (PHGMS), due to its reliable operation, simple combination and resistance to mechanical entrainment. They are now used to beneficiate oxidized iron ores, ilmenite, and wolframite, etc., and to purify wastewater. The combination of variable diameters rod elements in rod matrix plays a decisive role in recovery most of the different size fractions of magnetic particles, thus generating a significant influence on the performance of PHGMS. Combination of variable diameter rod elements in rod matrix on PHGMS is investigated in combination of 3 mm and 2 mm rod elements in rod matrix, by Slice-Matrix Analysis (SMA); it was found that the recovery of combinatorial rod matrix is higher than single diameter of matrix on PHGMS.

Abstract: This paper deals with the use of vegetable oils as fuels for internal combustion engines. The use of pure vegetable oils is usually not possible due to its properties, especially for higher density and viscosity. If vegetable oil is used as 100% fuel, then it cannot do without adjustment of the engine. Without adjustments of the combustion engine the fuel can burn blended with vegetable oil so it does not significantly exceeded the requirements of the internal combustion engine to its properties. Application of admixtures of rapeseed oil and oil from Jatropha Curcas in ratio 5.5 and 19.7% provides minimal to almost no effect on the performance parameters of the internal combustion engine, but positively translates to reduce emissions (particularly smoke and carbon monoxide).

Abstract: The present work is aimed to free vibration characteristics of marine propeller in fluid, and analyze the influence of fluid inertial effect on propeller. The fully coupled three dimensional finite element method is applied, and the commercial finite element code, ANSYS WORKBENCH, has been used to perform modal analysis for both wet and dry configurations via fluid-structure interaction APDL commands for secondary development. On this basis, analyze a marine propeller in air and in fluid with finite element analysis, then the differences of natural vibration frequencies and vibration modes of the propeller for different boundary conditions are discussed. In addition, the natural frequencies curves are presented. Results show that the natural frequencies of propeller in fluid are significantly lower than those in air, the fluid inertia effect also has some influences on vibration mode.

Abstract: The process of running-in machines is a significant period of operation of the machine. This is not uniform in material but also in terms of time. The article describes a specific individual storylines that just in the context of the run-run. It also describes the composition of individual particles that arise during this period, describing their size, morphology and diversity against the regime after running-in machines. The experimental part deals with the particle analysis method ferrography as a non-invasive technique. For analyzes were 3 tractor machines, which have been collected and assessed primarily levels and intensity of wear of individual samples taken from 0 to 15 mh. Were subsequently analyzed the running-in modes of individual machines and designed tribological verdicts.

Abstract: Based on the multi-body system dynamics in the ADAMS environment, a virtual prototype of crane hoisting mechanism was developed. In this model, the whole system was disassembled lifting mechanism system with flexible body dynamics model of the wire rope. The virtual running environment was established according to the actual working conditions, which is designed the lifting working process with rope-movable pulley contact. It is the key step to build hoisting mechanism dynamics model for performance analysis of system dynamics, which is the basis for the optimize design of hoisting mechanism. Virtual prototype simulation results will be applied to prototype design and evaluation, and save a lot of manpower and material resources. At the same time, the method has an advantage for dynamics analysis to simulating some dangerous movement conditions, which is hard to be replayed or simulated at the test actual working condition site. In particular, some cases cannot be recurrence in the accident handling process. Variable stiffness contact characteristics of wire rope-movable pulley of hoisting mechanism are implemented successfully through discrete multiple rigid body are applied to the wire rope in this paper , the establishment of a crane hoisting mechanism dynamic model is based on ADAMS, which realize hoisting mechanism flexible simulations, running virtual environments of hoisting mechanism is established, these results show that the model reflected the actual dynamics of hoisting mechanism, also present that some of the theoretical analysis results cannot confirm.

Abstract: A comprehensive numerical method to optimize a helicopter gearbox housing vibration characteristic is presented. Thicknesses of all the shells are considered to be design variables. The variables that have more effect to the responses than others are found by sensitivity analysis through orthogonal experiment, decreasing computational cost and improving the efficiency. An adaptive response surface method is applied to maximize the first-order natural frequency with the constraint of stress and mass to reduce structural vibration and satisfy strength and mass requirements at the same time, which is a multidisciplinary optimization problem. The results show that the maximum nodal displacement frequency response is lessened 58% and the maximum element stress is 29% less than the original housing structure.

Abstract: The purpose of this study aims at performing the kinematic study of the coil winder with a RCRC mechanism by investigating the geometry and conducting kinematic simulation. First, the motion principle of the shuttle is addressed. Then, the topological structure of the RCRC mechanism is examined, and its kinematic chain and kinematic sketch are drawn. Finally, a design example of the RCRC mechanism is given for illustration, and its feasibility is verified by performing kinematic simulation using ADAMS software. Finally, the simulated result shows that the shuttle can produce the required winding motion.

Abstract: In this paper, the mathematical model based on modern design methods of machinery used to optimize the parameters of the two-stage chain transmission system was established. The optimization toolbox of Matlab was introduced as well. Optimization results showed that, the pitches of first and second-stage chains were 19.05 and 25.4 respectively; compared with the original scheme, transmission ratio of first-stage chain decrease from 2.57 to 1.77, while the second-stage increase from 1.0 to 1.45. The number of chain strands of second-stage chain decreased from 2 to 1. The teeth number of the driven sprocket of the first-stage chain decreased also from 59 to 41. Total weight of the sprockets of the chain transmission system decreased from 25.40 kg to 14.84 kg, at least 41.57% material was saved and not less than 50% production cost was reduced. The optimization method is simple, feasible and the optimized parameters are reliable in practice.

Abstract: Based on failure analysis of CNC lathe capstan turret and building failure tree, according to the fuzzy information provided by the users, engineers and technician, the failure rate is defined as a set of trapezoidal fuzzy number. By means of fuzzy operation, the paper determines the failure fuzzy probability of the capstan turret. By analyzing the calculation results, It proves that this method can be applied to the reliability analysis of CNC lathe capstan turret subsystem, provide a reference for modification design of the capstan turret subsystem.

Abstract: Mechanical arm plays an important role in the mechanical systems, which is widely implemented in many engineering areas. Nowadays, the flexible manipulator attracts wide attention due to its flexibility. In this paper, implemented considering the complex configuration of the flexible manipulator system, especially the flexibility of flexible mechanical arms and joints, the dynamic model is established by using mechanical admittance and transfer matrix method. In this model, the compound vibration displacement of flexible manipulator is defined as evaluation index. Taking the double flexible mechanical arm as an example, the internal structure parameters and the influence of external configuration of the terminal compound vibration displacement are analyzed respectively.