Advanced Materials Research Vol. 487

Abstract: Strontium ferrite modified 0-3 cement-based piezoelectric composites were produced with piezoelectric ceramic [0.08Pb(Li1/4Nb3/4)O•0.47PbTiO3•0.45PbZrO3], sulphoaluminate cement and strontium ferrite by compressing technique, and the effects of poling conditions on the piezoelectric and dielectric properties were investigated. In order to contrast, a unmodified 0-3 cement-based piezoelectric composite was fabricated. The results show that the higher the poling electric field, the longer the poling time and the higher the poling temperature, the composites have the higher piezoelectric strain factor d33, piezoelectric voltage factor g33, dielectric constant εr and dielectric loss tanδ， and the strontium ferrite modified composites are polarized more easily, and have better properties than the unmodified composites. In the meantime, the optimum poling conditions were obtained, and the optimum poling field E, poling time t and poling temperature T were 5 kV/mm, 20 min and 80 °C.

Abstract: The underground water supply pipeline information system used currently is short of describing the pipe in three dimensions. Aiming at this point, the 3D underground pipe information system was achieved with the help of three-dimension graphics tool (VTK) in this paper. With the system, users can browse the 3D underground pipes and search interrelated datum, which raises the efficiency and standard of city digitizing management.

Abstract: In order to improve design safety and reliability on ship-borne loading device, dynamic model of a ship-borne loading device was built based on ADAMS. Wave excitation under 5 and 8 level of sea state were loaded on the condition of limit marine working environment. Kinetic property of ship-borne device was simulated, dynamic behaviors of key parts were also analyzed. Mechanism optimal strategy was proposed and verified by increasing horizontal roller layout and extending gap between horizontal roller and track, providing with an analysis tool for the optimization design of ship-borne device.

Abstract: Also known as virtual reality or virtual reality environments virtual environment, is rapidly developing a comprehensive computer and interactive graphics technology, which integrates computer graphics, multimedia, artificial intelligence, multi-sensor, network parallel processing, the use of computer-generated three-dimensional space image synthesis technology to achieve the goal, through visual, hearing, touch, in order to render the graphics and animation, the viewer, "seeing is bright." Virtual reality technology is an integrated building design approach, designed to reduce labor intensity, shorten the design cycle, improve design quality, saving investment. Designers to design the building and engineering units can communicate with each other on the World Wide Web.

Abstract: With extending range of modern unguided rocket projectiles, the dispersion is also becoming larger. An acceleration autopilot during terminal guidance is able to reduce the dispersion, improve the accuracy and comprehensive performance of a spinning rocket projectile. However, an autopilot designed at a given point can not reach good performance because the aerodynamic forces\moments and Mach number vary greatly during the terminal guidance. Via gain scheduling, an adaptive acceleration autopilot of the spinning rocket projectile is designed with considering the coupling of the servo system. The numerical simulations show that this acceleration autopilot is effective and adaptable.

Abstract: By the Picard iteration and Arzela-Ascoli Theorem, we first derive a sufficient for the existence of positive entire solutions to a class of initial value problems for a first order differential systems, then give all the infinitely many nonnegative entire solutions for the autonomous system.

Abstract: Evacuated Tube Transportation (ETT) will be the fastest traffic mode on earth in the future, possible over 6000km/h, and low energy consumption, no air pollution, no noise and relatively safe. Different from pipelines for transporting oil, gas and water, the tube of ETT will bear the maglev vehicles running in it, and it should be with reliable airproof ability for keeping required vacuum in the tube. It’s significant to seriously select the proper materials for creating tube wall and design reasonable tube wall structure. In this paper two materials to be used most possibly, steel and concrete, are considered. In addition, some types of tube wall structure are analyzed. This paper also compares the differences on the manufacture, process and construction of ETT tube between the pure steel tube and concrete composite tube. At last, some conclusions are given, some suggestions are put up, and some issues that need to be further analyzed and studied are listed.

Abstract: In order to improve the design efficiency of wind turbine tower, a design method which combines configuration and parametric design is proposed, the general structure model of wind turbine tower is given, and the parameter relation model of tower components is established. Based on skeleton and coordinate system coincident method, the automatic assembly of 3D tower model is realized. An automated 3D design software system of wind turbine tower is built by the API of Pro/E. The validity of the system is proved by wind turbine SUT-1500.

Abstract: In this paper, modal strain energy method is employed to calculate the modal loss factor of embedded and co-cured composite damping structure (ECCDS). To illustrate the validity of modeling and calculating method, the simulation results are compared with the experimental data. The effects of thickness, number and location of damping layers on damping performance of ECCDS have also been studied in detail.

Abstract: Based on the designable mechanical characteristics of composite structure, a secondary vulcanization method of viscoelastic material is developed to manufacture the experimental specimens of embedded and co-cured composite damping structure (ECCDS). The mid-temperature co-cured process of the composite material embedding viscoelastic damping membrane is explored according to the glass fabric/epoxy composite cure cycle. By using a standing wave tube method, sound insulation performance of the composite damping structure is tested and compared with the composite laminates without the damping layer. The conclusion indicates that ECCDS has a very strong potential to insulate sound.