Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 6 Articles
The customization (automation) of helical compression spring design, in solid modeling with creo can be interface of MS Excel software working under windows operating system. Helical compression springs are most commonly used in suspension system. For better working of helical compression spring and manufacturing is very important. In this paper design of helical compression spring was considered as easy way, out of traditional design process. Using parametric and its relationship the parametric concept was implemented for helical compression spring designing. Data from MS Excel worksheet was transferred to creo parametric and creo update the solid geometry which improves the automation of production of design. In order to develop MS Excel worksheet all the design procedure and input data are necessary. Cold drawn plain carbon steel with an ultimate tensile strength 1090 N/mm2 and modulus of rigidity of 81370 N/mm2 carried out suitable material for designing of helical compression spring....
Aimed at enhancing the effectiveness and efficiency for offshore plat form project scheduling, a multi agent collaborative scheduling\nmodel based on the analysis of distributed offshore platform project scheduling was proposed. The functional definitions and\ninternal structure of agents in the proposed system were analyzed. Moreover, in order to explore the cooperative way of agents,\ncommunication mechanism was presented and a negotiation model was elaborated. Then, system architecture and hardware\narchitecture were constructed to lay a foundation to develop the collaborative scheduling system. Finally, an intelligent algorithm\nbased on Bayesian method was designed to verify the negotiation model and a prototype system was developed to test the feasibility\nand rationality....
Cold rotary forging is a novel metal forming technology which is widely used to produce the high performance gears. Investigating\nthe micro structure and mechanical property of cold rotary forged gears has a great significance in improving their service\nperformance. In this study, the grain morphology in different regions of the spur bevel gear which is processed by cold rotary forging\nis presented. And the distribution regulars of the grain deformation and Vickers hardness in the transverse and axial sections of\nthe gear tooth are studied experimentally. A three-dimensional rigid-plastic FE model is developed to simulate the cold rotary\nforging process of a spur bevel gear under the DEFORM-3D software environment. The variation of effective strain in the spur\nbevel gear has been investigated so as to explain the distribution regulars of the micro structure and Vickers hardness. The results of\nthis research thoroughly reveal the in homogeneous deformation mechanisms in cold rotary forging of spur bevel gears and provide\nvaluable guidelines for improving the performance of cold rotary forged spur bevel gears....
A numerical study on the aerodynamic performance of wind turbine airfoils and their modifications has been carried out to\nunderstand the effects of maximum relative thickness and its position on the lift enhancement of blunt trailing-edge modification.\nFirst, the airfoils (NACA4409, NACA4412, NACA4415, and NACA4418) with different relative thickness are modified to be\nsymmetrical blunt trailing-edge airfoils with the software of XFOIL. Then, the lift and drag coefficients of NACA4412 airfoil are\ncalculated using S-A and K-? SST turbulence models, respectively. By comparing the numerical results with the experimental data,\nit is proved that the accuracy of K-? SST model is higher than that of S-A model. Finally, the aerodynamic performance of the\noriginal and modified airfoils, based on the K-? SST turbulence model, is investigated to analyze the increments of lift coefficient,\ndrag coefficient, and lift-drag ratio. Results indicate that the increments of lift coefficient and lift-drag ratio increase first and then\ndecrease with the increasing ofmaximum relative thickness. Furthermore, as the relative thickness position is gradually close to the\nleading-edge, the lift coefficient increment decreases, and the lift-drag ratio increment becomes almost negative.The investigated\nresults can provide a reference for designing blunt trailing-edge airfoil of a wind turbine blade....
As regards omnidirectional driving, conventional one- and two-pendulum spherical robots have a limited capability due to a\nlimited pendulum motion range. In particular, such robots cannot move from a stationary state in a parallel direction to the center\nhorizontal axis to which the pendulums are attached.Thus, to overcome the limited driving capability of one- and two-pendulum\ndriven spherical robots, a passive version of a spherical robot, called KisBot II, was developed with a curved two-pendulum driving\nmechanism operated by a joystick. However, this paper presents an active upgraded version of KisBot II that includes a DSP-based\ncontrol system and Task-based software architecture for driving control and data communication, respectively. A dynamic model\nfor two-pendulum driving is derived using the Lagrange equation method, and a feedback controller for linear driving using two\npendulums is then constructed based on the dynamic model. Experiments with several motions verify the driving efficiency of the\nproposed novel spherical robot....
Watermedium hydraulic systems are widely used in coal miningmachinery. As the power of hydraulic system becomes higher, the\nflow and pressure of water medium relief valve are also higher, and the flow may reach 2000 L/min. However, there is no relevant\ntest-bed which could provide instantaneous high-pressure and high-flow to support the experiment for high-flow relief valve;\nconsequently, this impact test-bed for high-flow water medium relief valve is designed to satisfy fast loading demand. Through\nbuilding model, simulation analysis, and construction of an impact test-bed of high-flow water medium relief valve, the dynamic\nperformance of high-flow water medium relief valve is detected. The setting pressure of relief valve, the accumulator volume and\nthe filling fluid pressure, and the damping of cartridge valve can be changed, and the dynamic performance of high-flow water\nmedium relief valve under different impact loads is detected.The results show that the designed impact test-bed of high-flow water\nmedium relief valve could provide required high-pressure and high-flow emulsion for the tested water medium relief valve, and it\ncould control the strength of impact load, which is an energy saving, high efficiency, and low cost method....
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