Advanced Materials Research Vols. 816-817

Abstract: On the basis of the dynamic equations of rotor system with pedestal looseness, the random response method of rotor system with pedestal looseness is researched. The method is based on stochastic perturbation theory and the Kronecker algebra, matrix calculus and random perturbation are used. The reliability model of rotor system with pedestal looseness is proposed. The reliability of rotor system with pedestal looseness is obtained by way of statistical fourth moment method, random perturbation technique. Numerical results are also presented and discussed.

Abstract: We propose an integrated design method to Network attack and defense Simulation training system. Firstly, taking the actual network attack and defense subjects as materials, establishes the system-related military scenario and models several use cases from the perspective of system resources and user needs. Then, using these use cases plans every system components (federate members) in terms of the distributed framework of HLA. More importantly, the workflow of a typical use case according to the publish/subscribe relationship among federate members is described. Associated with this use case, the structure (and behavior) model, internal/external class and program points of the system are modeled, defined and designed respectively. Finally, the expansibility of the system is described in detail. This method can accurately grasp the properties, functions, behaviors and other characteristics of system members (objects) and improve the rationality and consistency of the simulation system modeling.

Abstract: From Uphaar Fire Tragedy to recent Mumbai Secretariat Fire accident shows how Vulnerable are Old Constructions, while new one are well designed with Necessary Fire Protection Systems. It is well known fact many of Old Structures in India doesnt have basic Fire Protection systems such as F.E. This paper is intended to study one of such old Constructions, a college Auditorium and Evaluate risk on loss of Life due to Suffocation and Thermal Injuries using Simulation

Abstract: Accurate acquisition of asynchronous motor rotor flux plays a significant part in the high-performance motor speed regulation system. For that reason, this paper gives the advantages and disadvantages of various methods for motor rotor flux observation based on the studying of them, also application guides are given. Finally, a combination model based on the voltage model of rotor flux observer and the current model of rotor flux observer is given, and simulation analysis based on the combination model is carried out by Matlab/Simulink to verify the effectiveness of it.

Abstract: As the development of petroleum industry, the various fields in the multiphase flow have become the importance research direction of the petroleum industry technology and the interdisciplinary. As a result, it becomes much more necessary for the parameters study such as the measurement of phase holdup to reproduce a variety of flow patterns in laboratory. The paper described one set of miniature high-precision multiphase flow simulation device, which simulated many flow patterns in both horizontal and vertical directions, providing a platform to study the other parameters in the multiphase flow.

Abstract: The rheological performance of gel ink was investigated by the experimental methods of steady-state shear rate scanning, dynamic stress scanning and dynamic time scanning. The results show that some rheological parameters (such as n, K, τ₀, and ect.) can be used to characterize the stability of gel ink.

Abstract: Complex analytical method is employed to study the motion of a kind of mechanism. The angular velocities and the angular accelerations of the connecting rod and the rocker are deduced. The motion trajectory and linear velocity of a key point are also given. The results of the given example show the feasibility and the effectiveness of the method and conclusions here.

Abstract: A mathematical model of the full power grid-connecting converter at grid side for permanent magnet synchronous generator (PMSG) under unbalanced grid conditions is built, double-frequency oscillation mechanism on DC voltage is analyzed, and the influence of active power ripple of grid-connecting impedance on dual current control is discussed. To suppress the double-frequency oscillation on DC voltage, and take the grid-connected impedance on active power into account, a dual current control strategy, which based on respectively orientating positive-and negative-sequence voltages,is proposed, and introduced the correction value of active power ripple of grid-connecting impedance to correct reference current of proposed control strategy. Simulation results show that the proposed control strategy can effectively control positive and negative-sequence currents,eliminate the DC voltage double-frequency oscillation,and improve harmonic characteristic of grid-connected current.

Abstract: This paper proposes a new flux observer, which combines a current model and a modified voltage model based on an adaptive feedback compensation method. And an adaption algorithm based on MRAS for simultaneous speed estimation is presented. The effectiveness of the proposed method is tested through simulation and is experimentally verified.

Abstract: Stretch-forming based on discretely loading is a new process for manufacturing three-dimensional sheet metal part, the stretching load is applied at discrete points on the two ends of sheet metal, by controlling the loading trajectory at each discrete point, an optimal stretch-forming process can be realized, and the formed surface with the strains and stresses more uniformly distributed are obtained so that the forming defect can be avoided. The numerically investigated results on the stretch-forming process of spherical sheet metal part show that, comparing with the traditional stretch-forming, the equivalent strain in the new process is reduced by approximately 30% and equivalent stress reduced by 10%, the range of the strain and stress distributions are reduced by approximately 30%.