Advanced Materials Research Vols. 753-755

Abstract: The accurate control of hydraulic actuator is critical for automatic transmission to launch or shift smoothly. The mathematical and simulation model of proportional flow valve based on Matlab/Simulink were established , and hydraulic actuator control arithmetic based on NNPC(Neuro Network Predictive Control) was introduced to realize accurate control of clutch displacement. The experiment was carried out and the rusults showed that the model of proportional flow valve was correct and hydraulic actuator intelligent control algorithm based on NNPC had good adaptive ability and high precision.

Abstract: This paper introduces a novel mathematical model that using the Hamiltons' principle to set up coupled dynamics model of gantry cranes with flexible cable. By using finite element method to solve the equations that govern the motion of the crane system. Numerical simulations for the coupled dynamics model are presented for various operating conditions, and compared to the simulation results of the model with cranes made with rigid cable under the same working conditions. From the consequence, we can get the effects of cable's flexibility on gantry crane's kinematical properties; According to the conclusions, this paper defines two parameters of the gantry cranes, and qualitatively analyzes the two parameters' effects on dynamics kinematical properties of gantry cranes.

Abstract: Assess the array element number of planar phased array antenna which suffers fragments combat damage. A single fragment damage as the research object, the simulation of penetration condition for Tungsten Spherical fragments is developed using the software of ANSYS/LS-DYNA. The penetration of antenna at 0°attack angel and 800m/s is simulated, and we can gain the penetrated distortion data. Based on the data the damage circular is calculated. The last one study was made on x-band planar array antennas, the array elements invulnerability of triangular setting is better than rectangular, and the influence characteristics between the position of the damage circle and the damage of the antenna. The results can be used in a rapid assessment of a battle-damaged Radar repair and maintain inventory of phased-Array element.

Abstract: DTH (Down-the-hole) Bits are widely used in engineering construction and mining but the design level of DTH Bits needs improving. The kinds of DTH Bits are various in the practical application. Meanwhile, design efficiency is low and management in design information of historical product is insufficient. To solve the problems, key features of the DTH Bits used in different strata are analyzed and SolidWorks secondary development system of DTH Bits is developed with VB.NET. The secondary development system runs in the same process with SolidWorks in the form of a plug-in. ADO technique is used to connect the system and database which stores design information of historical product. It proves that the secondary development system can improve design and management efficiency of DTH Bits.

Abstract: Large scale aspherical optical component plays an important role in National defense industry. It is based on the large size aspherical machine tools, so the stiffness and accuracy of the machine tools lead to the accuracy of the mirror directly. The tools consist of a turntable shaft and three linear axes including X/Y/Z axises. This paper analyzes a desirable arrangement of Y-axis linear motors so that the error of Y-axis produced indirectly can be minimized.

Abstract: According to the design method of composite material mechanics based on laminate theory, structure of an underwater vehicle, which is made of twill woven carbon fiber composite material, was analyzed simulatively under the lifting condition with the finite element analysis software. Performance parameters of the laminated composite material were obtained from the mechanical performance testing experiment and applied to the analysis. In the two point handling condition, for the underwater vehicle structure, maximum deformation or displacement has a large safety redundancy to the test standard value. And the structure maximum stress is far less than the allowable strength limit of carbon fiber laminated plate acquired from the tensile experiment. It has an obvious advantage compared with metal frame structures.

Abstract: In allusion to the numerous nonlinearity factors affecting precision in the cut process of cross-cutting line modeling shear and the difficulties to build precision mathematical model controlled by shear, the essay adopts BP neural network to build model of shear precision compensation system. By Matlab simulation experiment, the data demonstrates nonlinearity complex system can be identified fast and effectively by neural network. The predicted time of the model is 97ms with the control precision within 0-2mm hitting 89%, proving that the model can fully fulfil production demands regarding precision and pace and prove that probability that BP neural network is used in precision compensation of cross-cutting line modeling shear.

Abstract: The bolts loose of the main limb is very important for the research of tower crane. We have established a dynamic simulation model of tower crane and physical experimental model, and have got the top trajectory of the tower crane through the above two models. The results show that the trajectory feature presents introverted region, and with increases of the loose bolts degree, the trajectory exhibit certain regularity.

Abstract: The model of three-span rotor-bearing system with three cracks in shaft supporting on the six sliding bearings was set up. The influences of crack faults to the responses of the rotor system were studied on numerical simulation. Along with the increase of the crack depth in first span, the main influence to the dynamic characteristics of the system is in the first span. Along with the increase of the crack depth in second span, the main influences to the response of first and third spans are in the region of critical rotate speed, and it to the second span is in the regions of critical and supercritical rotate speed. Along with the increase of the crack depth in third span, the main influences to the response of the three spans are in the region of critical rotate speed.

Abstract: Due to of nonlinear performance and variable rigidity characteristic vehicle equipped with air suspension has more progress in the driving smoothness and handling stability. In the analysis based on the characteristics of air spring and the principle of gas flow, the paper aims at obtaining the relation curve between stiffness of air spring and on/off time, therefore, the calculation of a example has been done, which provides the valuable basis for the bench tests of air spring and vehicle control test.