Papers by Author: Yong Liu

Abstract: The article proposed a kind of new structure for aircraft tire, which includes double firm rings. The aircraft tire of double firm rings was simulated in the instant of landing by finite element analysis, then the simulation result was compared with the one of ordinary aircraft tire. The result indicated that the grounding area and deformation of aircraft tire with double firm rings was less than that of ordinary aircraft tire, which can decrease the rolling resistance and improve high speed performance. In addition, the larger contact pressure located the central region of the contact surface, which can reduce the damage of shoulder rubber and lengthen the life of the aircraft tire.

Abstract: Three different kinds of carcass A, B and C for aircraft tires were presented in the article, which is based on the different length of rolling up for carcass cord across the bead ring. And then they were simulated by applying finite element analysis method when aircraft tire was landing in an instant. The simulation results indicated that, the carcass structure of rolling up from the side of bead extending to the other bead (A type) has the minimum deformation, which can reduce the outward of bulge for the side wall and effectively resolve the failure problem for rubber in the sidewall of tire , what’s more , it can prolong the life of aircraft tire to a certain degree and provide good braking performance.

Abstract: The falling process of melt electrospinning jet is different from those of solution electrospinning in which there is apparent solvent volatilization. In order to study the factors influencing on the forming process of fibers in melt electrospinning, dropping process of fibers is recorded and analyzed via high speed video camera in the article. Results showed that there was an optimal spinning temperature for melt electrospinning of the polymer; the greater the voltage was, the more obvious stretching action on jet was. However, the voltage did not exceed a certain value, because there was a spinnable voltage limit corresponding to every receiving distance. When the spinning distance was generally short, the jet swinging radius decreased with increasing spinning distance; when the spinning distance was long, the jet was subject to the influence of the environment temperature easily. The changes of viscosity had dominant influence on the motion of jet.

Abstract: In this article, three kinds of belt named B, C and D type are invented, then their main performance are compared with the other two kinds of belt structures introduced in previous papers. Simulation results showed that B and D-type belts are better than the other three. Comparatively the latter needs less material, its molding process is easier, and the tire body is lighter than B type tire, so in general it can be considered that D-type belt is the best among the five kinds of belt structures.

Abstract: In order to get a soft and enclosed vesicle which can endure an instantaneous high temperature and super high pressure the soaking technology of aramid fiber with Room Temperature Vulcanization silicon rubber and liquid polyurethane was studied. Then the performance of the composites was tested. Two kinds of rubber vesicle were made, one with metal valve and another without the valve. Using three-dimension braid method, aramid fiber vesicle was made outside the rubber vesicle. Compression test results of the composite vesicle showed that no-valve rubber vesicle had a good match with the aramid one and endured a very large pressure. It can transfer the liquid pressure from inner vesicle to the outer one, which the aramid fiber has excellent mechanical performance and can endure a very large compression.

Abstract: The current work is a continuation of Part I. In this part, the simulation results showed that the free tire contour changed measurably after charging and installing it on a steel rim. A distinct stress concentration appeared on the tire shoulder part whenever the tire was charged, touching ground or rolling. When the rotational velocity of the free tire changed, the displacement of the tire crest remains stable while the tire shoulder changes considerably.

Abstract: As an economical, resultful and direct method, finite element method has been used broadly to simulate tire performance. However, much of the published research shows few detail model or no material constants. It is difficult for readers to judge if the result is reliable. To ensure simulation results are credible, the material constants, simulation model and analysis method must be dependable. In the current work, the three-dimensional radial tire models, finite element models of free and ground-touching tires, were built and showed in detail. The material constants measured from experiments in a tire factory were published. Using the well-known finite element simulation software ANSYS, the current research found some interesting results which will be presented in Part II.

Abstract: Melt electrospinning is a safer, more environmentally friendly and cheaper alternative to solution electrospinning in producing superfine fibers. In this paper, a novel melt electrospinning device was used, which has higher efficiency than conventional equipment. Polypropylene is widely used in many fields and it is difficult to find a suitable solvent for its solution electrospinning at room temperature, so it was chosen in this study. The influences of the electrospinning parameters such as temperature and voltage on the diameter of the spinning fibers have been studied. Temperatures higher than normal processing temperatures were used in present electrospinning system in order to reduce the viscosity of the polymer melt sufficiently. Good quality fibers with smooth surfaces and with diameters mostly smaller than 10 microns were spun successfully. It was found that there was an optimum point for the spinning voltage (70-80KV) and the temperature (230-260°C) to get fine fibers.

Abstract: In this paper, self-designed electrospinning equipment was used to make a series of electrospinning experiments with materials of polypropylene. The influences of the receiver area, the upper plate area, and the overlapping area between the receiver and the upper plate, on the melt spinning electric field, the spinning efficiency, and the fiber diameter, were investigated respectively. The results showed that when the other parameters were kept unchanged, with the increase of the receiver’s diameter, the electric field strength and spinning efficiency increased, and the fiber diameter increased at first and then decreased; the bigger the overlapping area between the receiver and the upper plate, the more stable the vertical spinning path.

Abstract: The typical roof tiles made from soil or clay will be limited because it destroyed the farmland. On the other hand, the old tire and waste plastic increase year and year, which bring a serious environmental problem. So the roof tiles made from old tire and waste plastic will help a lot to decrease above environmental pressure. To get a suitable formula of roof tiles made from waste rubber tire powder and waste plastic, the present article studied mechanical performance of a series of composites. Then a preferred formula was got through comparing the mechanical performance.