Applied Mechanics and Materials Vols. 457-458

Abstract: The solving process of the hyperbola function method is introduced in this paper. By using hyperbola function method, the analytical solutions of nonlinear wave equation of a finite deformation elastic circular rod and the variant Boussinesq equations are studied. The more physical specifications of these nonlinear equations have been identified.

Abstract: Based on requirements of accuracy and velocity, the speed-controlled twist-roller transmission is designed and its working principle is particularly discussed according to friction transmission theory. Then the corresponding mathematical deduce is given. After the strength check and feasibility analysis of the transmission agents, ADAMS is used in kinematics analysis for the designed transmission agent. Finally, some related conclusions on transmission agents stationary are got. KEYWORDS: twist-roller transmission; friction; motion simulation analysis;

Abstract: To more accurately learn reliability on anti-overturning stability for a truck crane, a parametric multi-body dynamics model is built in a dynamic software environment with overall key parameters as design variables. On this basis, stability criteria of this truck crane are established according to the working conditions and crane dynamics simulation results. After a truncated normal distribution sampling method is given for design variables which will effect on truck crane's stability, the reliability analysis of this truck crane is done via Monte Carlo method. The result indicates that the truck crane's stability reliability is 0.9998 in the most dangerous working condition. Analysis shows that the reliability calculation of truck crane anti-overturning stability is feasible using modern multi-body dynamics and Monte Carlo method, and the results are more accurate than conventional safety factor method.

Abstract: This study aims to produce bacteriostatic fibrous membranes, and polyvinyl alcohol (PVA), sodium alginate (SA), and Angelicae Dahuricae Radix (AC) are used to form PVA/SA/AC fibrous membranes. This study uses different solvents for the extraction of AC extracts. Fiber types, ultraviolet absorption spectrum analysis, and bacteriostatic property test are performed on the resulting fibrous membranes to evaluate bacteriostatic effects of different solvent and extraction times; thereby determining the optimal AC extract. The experiment results show that AC that extracted with ethanol for 48 hours provides resulting membranes with significant bacteriostatic effect.

Abstract: Global warming increases each day and causes people to pay more attention to the reduction of carbon dioxide emission in order to mitigate the increase in temperature. Reducing, reusing, and recycling can effectively reduce the emission of carbon dioxide, to attain goals of energy conservation and carbon reduction. This study aims to explore the difference in the punch resistance and impact strength between the polyethylene terephthalate (PET) nonwoven fabrics and PET/TPU honeycomb grid/PET (P/T/P) composites. Recycle PET, high strength PET, and low melting PET are made into PET nonwoven fabrics, two layers of which are laminated with a TPU honeycomb grid, the interlayer, to form P/T/P composites. The constant rate puncture resistance, dynamic puncture resistance, and impact strength of PET nonwoven fabrics and P/T/P composites are evaluated. The experiment results show that both the constant rate and dynamic puncture resistances of P/T/P composites are lower than those of PET nonwoven fabrics.

Abstract: The compressed air energy storage (CAES) has a promising application prospect to ease electic load and match intermittent renewable energy, such as solar and wind energy. The release process influences the output power and system performance. In this paper, a mathematical model is built to simulate the release process of a micro-CAES system with screw expanders. The results show that the rotation angles of suction, expansion and discharge processes are depended on the volume ratio. The chamber volume of 2^nd stage expander is larger than the 1^st stage one for two expanders. In the constant suction pressure (CSP) condition, the mass remained in the tank is lower slightly than it in the various suction pressure (VSP) condition for the same set pressure in the tank. The CSP condition needs more time to finish the release process. The decrease of air temperature in the CSP condition is smaller than it in the VSP one. The power output decreases with time in the VSP condition, but it is a constant value throughout the release process in the CSP condition. All the average output and the total work in the VSP condition are larger than them in the CSP condition.

Abstract: To improve the transversal stability and lateral stiffness, this paper develops a new type of pneumatic single bending joint. The single bending joint is pneumatic composite elastomer, and its driving system combined into one. The inside of the joint is elastic rubber tube and the outside is a set of closely constraints ring suit. When supplied the air pressure, the joint bends under the action of the bending moment generated at the end of the joint. The bending experiments have been done on the static experimental device and the relation between the bending angle of joint and the air pressure is acquired.

Abstract: The well testing model of nonlinear spherical percolation problems for composite reservoir is established under three different outer boundary conditions: closed boundary,constast pressure boundary,infinity boundary. the mathematical model are linearized by using variable substitution method, and then its solutions are derived by Laplace transform. According to the theory of similar structure of solutions to the differential equations, we obtain the similar structure of the solutions .The theory of similar structure is beneficial to understand the inherent laws of solutions and analyze the influence of parameters to solutions.

Abstract: The mode of the impeller of steam turbines vibration frequency is recorded by simulated experiment of the impellers vibration in the exciting method. And the main negative effects for the impeller of steam turbines vibration are analyzed through the simulated experiment, so the impellers vibration can be avoided through modulating the targeted elements. The accident during the steam turbines running caused by the impellers vibration can be decreased.

Abstract: High power LED headlamp cannot operate normally and efficiently in case the maximum junction temperature exceeds 120°C. Therefore, it is essential to install external cooling device with excellent thermal management. A model based on plate-fin heat sink is presented, the heat transfer plates (HTPS) are added to bridge aluminum substrate and heat sink. And its thermal performance is evaluated compared with the one only installing heat sink. Results reveal the HTPS coupled with heat sink has a good cooling performance. In addition, the correlation between the junction temperature and the HTPS length is investigated. The optimum length is 47 mm. Furthermore, considerable simulation and experiment are conducted on the junction temperature variation subject to input power, ambient temperature, as well as the installation angle respectively. Finally, a fan is added based on the original device to enhance cooling. It indicates that the junction temperature decreases gradually with the presence of velocity air flow.