Advanced Materials Research Vols. 479-481

Abstract: When a vibration force acts on piezoelectric material, which will deform to-and-from and excite electricity on its polar surfaces. In this paper, the air resonance structure is designed by the principle of air self-oscillation, when the shells are flying with high-speed, the air into the shells will produce self-excited oscillation, the oscillation frequency only relates to the structure of the resonator rather than the speed of the wind which causes the oscillation of piezoelectric ceramics to produce a continuous charge, storage devices are used to store the charge, as regulated, the voltage is used as the power supply circuits of the fuse circuit.

Abstract: A new analytical method for vibration fatigue life of cracked beams was proposed with the structural response changes as crack growth. In analysis, the damping loss factor was introduced by the complex elastic modulus, and the crack growth was simulated by employing a Paris equation, and the coupling effect of vibration and crack growth was considered through vibration analysis and estimation of fatigue crack propagation cycles by cycles. Results indicate that impacts of exciting frequency and damping on the crack growth are obvious. The resonance fatigue crack growth rate decreases rapidly when big damping is involved, and the first mode is more important to the crack growth than that of other mode.

Abstract: Through considering the influence factors of ultrasonic excitation parameters, the nonlocal kernel parameter formula under ultrasonic excitation is established and the nonlocal elastic kernel function is also deduced. The attenuation characteristics and effects of the elastic kernel function are also studied in this paper. The nonlocal stress under ultrasonic vibration is calculated based on the nonlocal elastic kernel formula. It is concluded that stress decay phenomenon can explain through nonlocal kernel function attenuation in frequencies.

Abstract: Pellet layers inside the rotary hearth furnace influences the interior temperature and reduction rate, so pellets must be distributed with a constant thickness .A special vibrating feeder is designed to distribute pellets.The working principle of vibrating feeder is analyzed and the differential equation of the outlet curve is derived .The differential equation is solved by the numerical method to obtain the outlet curve’s orthographic projection on the hearth. Under the conditions of lower broken rate and good dispersion, vibrating strength and optimal vibrating angle, vibrating frequency and exciting force are calculated by the theoretic computing method. Finally, an experiment is operated. Its result shows that pellets can be evenly distributed with a low broken rate when the exciting force is close to the theoretical value.

Abstract: The bogie technology of the 350km/h EMU train is one of the key parts for China high speed railways. Through analysis of the high speed bogy for CRH3 EMU train, the design conceptions and methodologies of the bogy structure and suspension systems are better understood. Technical procedures for the bogie design are carefully investigated, which includes the wheel/rail interaction, helical spring and high property rubber pad used in primary suspension, high flexible and large convolution bellows type air spring, anti-roll bar and two point control of air springs used in secondary suspension, and the elastic frame suspended structure used for traction motor. Comparison between different bogy techniques are carried out by using the dynamic simulation, roller rig test and field test, and the efficient way to raise the bogie running safety and reliability is analyzed.

Abstract: Thermal load is non-ignorable in the design and analysis of high precision and reliable space deployable structures. A new approach based on flexible multibody system is presented in order to investigate the thermoelastic effect on the deployment of space structure. Dynamic equations of an Euler Bernoulli beam element with transient thermal load are derived in Absolute Nodal Coordinate Formulation. The temperature distribution in the beam section is assumed as linear, which is reasonable for slender beams. The resulting generalized thermoelastic forces can be decomposed into thermal axial force and thermal bending moments, which can cause tension/compression and bending of the beam respectively. The dynamic equations of the beam element are then assembled into a flexible multibody system. Deployment analysis of a space mechanism with transient thermal load is studied with the new approach. Simulation result shows that thermoelasticity could cause static deformation of the final configuration as well as affect the external driving forces.

Abstract: At present, one pumping corresponding one oil well exploitation pattern has been unable to meet the cluster well oil recovery characteristics of muti-well platform. Single-well pumping unit’s torque factor is too large, resulting in the peak of the net torque of the crank shaft is too large and the fluctuation is too large, which lead to the increasing of the pumping consumption. Slider-crank type cluster well pumping unit can realize a pumping unit driving several wells pumping and make use of the principle of rod load balancing each other, no need of special balance block, having good balance effect, the crankshaft net torque having smaller peak and energy saving effect is obvious .Proposing the cluster well pumping unit design program based on slider- crank type mechanism, establishing the corresponding motion and dynamic analysis equation and analyzing the performance of slider- crank type cluster well pumping unit based on the actual load conditions.

Abstract: In order to satisfy the requirement of optical system positioning in SG-III facility, the target area support system should provide a stable platform for optical elements. The target area support system includes a rectangular target area building, target chamber support structures and a switchyard steel frame. The vibrational stability of the target area support system will be achieved through a combination of structure design, large modal damping material, and friction dampers. Finite element analysis has been used to evaluate the target area support system. The rotation drifts of the transport mirrors, the translation drifts of the focal lenses, and the translation drift of the target are obtained. The orientation errors of each beam in target area system are less than 12.9μm based on the relation between the beam orientation error and optics elements drifts. And the safety factors are 1.44 to 2.3. The design of the target area support system has satisfied the stability requirements.

Abstract: An efficient 3D incompatible element for the simulation of Flexible Multibody System (FMBS) is derived based on the principle of virtual work and the theory of continuum mechanics. The presented incompatible element uses absolute coordinates and internal parameters for the degrees of freedom and fixed the locking problem under the state of pure bending. Considering the geometric nonlinearities and using the Total Lagrangian Formulation, system dynamic equations are derived and then solved by the Backward Difference Formula (BDF) in conjunction with Newton-Raphson algorithm. Eigenvalue analysis and dynamic analysis of several numerical examples are presented to show the convergence of the 3D incompatible element and excellent performance in terms of accuracy and time efficiency comparing with standard linear and quadratic hexahedral elements.

Abstract: Using the generalized interval arithmetic we give a generalized cholesky decomposition. Generalized intervals (intervals whose bounds are not constrained to be increasingly ordered) extend classical intervals providing better algebraic properties. In particular, the generalized interval arithmetic is a group for addition and for multiplication of zero free intervals. These properties allow one constructing a cholesky decomposition of a generalized interval matrix A: the computed generalized interval matrix L satisfy A=LL^T with equality instead of the weaker inclusion obtained in the context of classical intervals.