Applied Mechanics and Materials Vols. 488-489

Abstract: The system considered in this paper is a half toroidal Continuously Variable Transmission (CVT) system for cars. The existing CVT controllers most adopt to PID to design the controller, but the precision and reliability do not meet the requirements of the CVT well. The ADRC (Auto Disturbances Rejection Controller) technology is able to solve the nonlinear systems whose model is difficult to get and has many uncertain external disturbances. The ADRC in this paper is used to combine with the half toroidal CVT to design a robust, reliable, anti-jamming and feasible controller.

Abstract: A online automatic indexable inserts detecting system,which is based on the five-axis CNC grinding system,is introduced in this paper. The probe of the system can complete the online detecting of indexable inserts by calling the macro measurement program. The measruements of the inserts can be calculated and input into the process module.

Abstract: Crankshaft is one of the important parts of reciprocating compressor. It takes a large reciprocating compressor crankshaft as the research object. First it establishes the three-dimensional solid model of the crankshaft by the software Pro/E. Then it contacts the Pro/E and ANSYS Workbench by the interface to establish the finite element model of the crankshaft. After taking the modal analysis and calculations of the crankshaft in the ANSYS Workbench module, it obtains the foundation for the design of the crankshaft structure.

Abstract: To adopting means to reduce power radiated from the hull, power injected by the shaft system and that radiated by the hull are analyzed for an underwater cylinder excited by the propeller/shaft system. As the power is injected by combination of the solely acting loads on the junction and there concurrent, power transmitted by each solely acting load, radiated by the hull and the concurrent power are compared to understand the mechanism of power transmission and transformation. In the comparisons, quantities are decomposed according to circum orders to understand the radiation modes. The conclusion drawn in the paper will provide some guidance for acoustic reduction by shaft isolation design.

Abstract: The static strength design of aircraft structure is the most basic design principles. The basic applicable conditions of composite structures static strength reliability analysis using the current methods were mentioned in this paper, and compliance analysis of these basic conditions was carried out. In addition, further studies were also conducted to research the influence of the number of full-scale structural specimens and environmental factors on the composite structures static strength reliability.

Abstract: The numerical model of the unsteady flow field of ducted propellers is based on CFD (computational fluid dynamics). By applying the numerical model, the unsteady flow field of the ducted propeller with the fracture in different positions of a certain blade is simulated and its unsteady hydrodynamic performance is numerically analyzed. By extracting the fluctuating pressure data of the duct inner wall monitoring points,the fluctuating pressure-time oscillogram of ducted propellers is obtained, and then the spectrum is obtained by FFT transformation of the oscillogram. A blade fracture fault diagnosis technology of ducted propellers, which combines oscillogram analysis method with spectrum analysis method, is put forward by analyzing and studying the oscillogram and the spectrum.

Abstract: In order to maintain the instruments calibration state in the process of use, they shall be carried out the period inspection. From the point of view of practical lab work, this article explains the necessity and usual methods of the test work in lab in the period inspection.

Abstract: For cooperating with automation of flow measurement in irrigation districts, the method of flow measurement needs to be improved. Considering that sedimentation may appear at most channels and comparing with common water measure equipment, cutthroat flume measuring flume become the most suitable flow measurement structure adopted in irrigation districts with the advantages of the simple structure, the lower upstream backwater, not easy to silt the flume and so on. In the background of the cutthroat flume of one channel in the Ye River irrigation district of Shijiazhuang and on the basis of RNG k-εturbulence model, the 3-D numerical simulation of the flow field of cutthroat flume is carried out to obtain the distribution of velocity field and pressure field. By comparing the calculation value of nodal velocity with the measured value of nodal velocity, the reliability of the result of numerical simulation is proved. The above conclusions provide theoretical basis for further optimization design of cutthroat flume.

Abstract: In the traditional proportional valve mathematical model, the nonlinear flow characteristics induced by the geometrical features in various flow areas were often ignored. To overcome this problem, the uniform nonlinear flow mathematical model for the electro-hydraulic proportional valve is constructed. The relational expression between the orifice flow of the proportional valve and the geometrical future and physical characteristics of spool is constructed to obtain a series continuous nonlinear flow equations of median positive overlap, negative overlap and zero overlap proportional valve. The experiment validates that, for positive overlap, the flow input into the hydraulic tank is proportional to the displacement of the spool in the dead zone. For negative overlap, even though the spool located at the median, the flow output also exists, and induces the piston movement of hydraulic tank. This situation is consistent with the non-matching overlap response of actual negative proportional valve.

Abstract: Aiming at billet stacking problem of the rolling mill, an IBF algorithm is used to assign the billet to the warehouse positions. The utilization of non-empty warehouse positions and shuffles are considered in the algorithm. Computational experiments demonstrate that the proposed algorithm is feasible and effective, competitive and able to find more high-quality solutions for problem instances than artificial method.