Advanced Materials Research Vol. 900

Abstract: The objectives of this particular research were testing covering materials for models and making Thai childrens standard sized models. The covering materials chosen for the models were hand-woven cotton fabrics from four sources. The sub materials were non-woven pressed fabrics. Data were statistically analyzed in terms of percentage, mean, standard deviation, and One way ANOVA. In relation to the covering materials, it was found that the differences of the tensile strength on Warp and Weft, and the static puncture test on hand-woven fabrics from different sources both before and after needle stitching were statistically significant at the level of .05. Concerning the developed prototypes of the fiber-glass models covered with material from Narathiwat Province which were for the 5-year, 7-year and 9-year old models, the satisfaction with the use of all three was an average of 2.40, or very good.

Abstract: Superplasticity at high deformation rates is desirable in order to make superplastic forming more practical. High strain rate superplastic behavior and microstructure of the rolled Mg-Gd-Y-Zr alloy sheet were investigated. For the purposes, tensile tests at the strain rate of 0.01 s^-1 were conducted, which revealed that the sheet exhibited elongations of 180%~266%. Post-deforming microstructures were characterized by optical microscopy, scanning electron microscopy and transmission electron microscopy, while crystallographic orientation information was obtained from macro-texture analysis. The results show that the high strain rate superplasticity was attributed to class-I creep accommodated by dynamic recrystallization. It is suggested from microstructural analysis results that the interaction between second phases and dislocation facilitated dynamic recrystallization. The macro-texture at the strain of 0.8 still exhibited some characteristics of the crystal rotation arising from dislocation slip despite the occurrence of DRX.

Abstract: Microhardness of various minerals in sinter was tested in order to better production of sinter with high microhardness minerals in WISCO. The results showed that the hematite microhardness was highest and the glass phase microhardness was lowest, the various minerals microhardness from highest to lowest was: hematitecalcium ferritemagnetiteglass phase. So the hematite and calcium ferrite should be development, and the glass phase should be inhabited in sinter on production. Minerals microhardness was connected with component elements and crystalline structure of the minerals besides ferrous content of sinter.

Abstract: Carry out research on the processes, structures and properties of the X70 corrosion-resistant pipeline steel and analyze the mechanism of the hydrogen induced cracking. The results show that: the developed steel not only has excellent mechanical properties, but also has good resistance to H₂S corrosion. Microstructure of the X70 corrosion-resistant pipeline is mainly the acicular ferrite and granular bainite, with well-closed formation and fine grains. Hydrogen Induced Cracking (HIC) begins with the appearance of the hydrogen blistering on the specimen surface, and cracks generated by the hydrogen blistering gradually extend inward from the surface along the grain boundary, diffuse inside the specimen gradually, and finally form hydrogen induced cracking.

Abstract: The stress and strain of the slipper of 35 MPa high pressure axial piston pump are analyzed by the finite element analysis method, and the following facts are revealed: in spite of the fact that the slipper can satisfy the use requirement in the aspect of stress, whereas, in the aspect of strain, the deformation of the bottom of the slipper increases with the pressure increase, and the deformation of the slipper has reached the order of magnitude of the oil film thickness under 35 MPa working pressure. Therefore, when the slipper pair of 35 MPa high pressure axial piston pump is designed and its oil film performances are studied, the influence of deformation of the slipper on the oil film structure must be considered comprehensively. The results of this study can provide some guides for developing 35 MPa high pressure axial piston pump.

Abstract: Using the methods of grenade explosion scattering the extinguishing agent for crown fire saves has been an important remote way for crown fire saves. Scattering the solid agent from explosion is greatly influenced by external environmental and airflow in fire, which results in the low efficiency of extinguishing agent. Dispersion area of grenade scattering extinguishing agent can be calculated through the combination of numerical simulation and experimental determination. On the base of high extinguishing concentration, the structure of grenade is optimized and the efficiency of extinguishing agent is improved. For monoclonal crown fire, specific central explosive about 1.5% and the ratio of height to diameter is 3.5, the extinguishing agent the dispersion uniformity, use reduced by more than 20%.

Abstract: In order to attenuate the deformation of spray boom, a finite element model built based on ANSYS, according to the reasults of numerical modal analysis and modal texting, the reliability of the finite element model was affirmed. Then, an isolator was introduced between spray boom and frame, a frame-isolator-spray boom model was built in ADAMS. The effect of the isolators which have different parameters was research, the reasult shows: The isolator has much effect on attenuating spray booms deformation, the stiffness of isolators spring dampers has little effect on spray booms deformation, but the damping of isolators spring dampers has effect on spray booms deformation.

Abstract: For the vibration of the super-long hybrid jib structure of hundreds of meters level elevating platform fire truck under water cannon impact load, linear dynamic response and nonlinear dynamic response methods were used to analyze the characteristics of the structure in the conditions of the large deformation of the structure, geometry, contact, material nonlinear and coupling. Through analyzing linear and nonlinear dynamic response results about peaks, steady-state values, amplitudes and dynamic load coefficients, the more scientific and practical method was given. The results provide scientific data for active vibration control and track control, and lay the foundation for achieving stable-work and pinpoint of the elevating platform. The results shows that dynamic load coefficients of each part of the super-long hybrid jib structure are not identical. The dynamic load coefficient of where lifting load is smaller and support part is larger. The larger gap between linear and nonlinear dynamic response results shows that linear dynamic response analysis should be taken as an estimation method, but nonlinear response analysis is more scientific and applied.

Abstract: In this paper the nonlinear transversal vibration of axially moving yarn with time-dependent tension is investigated. Yarn material is modeled as Kelvin element. A partial differential equation governing the transversal vibration is derived from Newtons second law. Galerkin method is used to truncate the governing nonlinear differential equation, and thus first-order ordinary differential equation is obtained. The periodic vibration equation and the natural frequency of moving yarn are received by applying homotopy perturbation method. As a result, the condition which should be avoided in the weaving process for resonance is obtained.

Abstract: In hydraulic suspension transport, the gelled crude oil particles are known to change shape in response to local flow conditions. The phase field method is used to simulate the deformation for the gelled crude oil particle with the same internal and external fluid viscosities. For this purpose, an Image Pro Plus software records the major and minor axises and thus, analyzes digitally its deformation degree. Initially spheroidal oil droplet is simulated and it is shown that the gelled crude oil particle exhibits deformation behavior as the movement and its final stable shape close to oval. The deformation behavior is response to shear stress with a time of 0.08s delayed. In the range of delayed time, the gelled crude oil particle deforms with a little degree and after the delayed time, the deformation degree increases seriously.