Advanced Materials Research Vols. 311-313

Abstract: The focus of this study is to experimentally investigate a semi-active magneto-rheological (MR) damper for a passenger vehicle, by using a quarter car models. After verifying that the damping force of the MR damper can be continuously tuned by the intensity of the magnetic field, a full-scale two-degree of freedom quarter car experimental set up is constructed to study the vehicle suspension. On-off skyhook controller is employed to achieve the desired damping force. The experimental results show that the semi-active vehicle suspension vibration control system based on MR dampers is feasible and can effectively improve ride comfort of vehicle.

Abstract: First, we prepared the Poly-methyl-acrylic Acid hydrogels by free radical reaction, then prepared the Sodium-Poly-methyl-acrylic and Sodium-Alginate blend-micro-spheres by the condensation phase separation method. The influencing factors of the form and the particle size of the blend-micro-spheres were investigated including the content of the Sodium-Poly-methyl-acrylic, the content of the Sodium-Alginate, the content of the calcium chloride and the volume ratio for the Sodium-Poly-methyl-acrylic solution and the Sodium-Alginate solution. We also give a research on the swelling influencing factors of the blend-micro-spheres and observed its internal and external form by the scanning electron microscope (SEM) ; The result showed that: we can get the favorable appearance form blend-micro-spheres when the Content of PMAA 4.0%，the Content of SA 4.0%，the Content of CaCl₂ 4.0%; and it had a important means when the volume ratio for the Sodium-Poly-methyl-acrylic solution and the Sodium-Alginate solution was 1:4 , 1:1.

Abstract: A kind of compact bending dielectric elastomer actuator is designed and manufactured using VHB4910 as the actuating material. In the contrastive experiments, the maximum displacement of 6.1mm can be achieved, and on the voltage differences of 0.9kv, the active bending of actuator is 8.1°. The research of dielectric elastomer actuator can provide an instruction for the design, analysis and implementation of this kind of actuator.

Abstract: An approach to identify damages in materials particularly aerospace composites has been developed based on application of wavelet analysis on guided wave transient signals. The wave response was convoluted against a suitable wavelet to present information in the time-frequency domain for baseline comparison of signals. By evaluating the time-frequency conditional moment, sensitive indices were computed to identify the presence of damage. Normalisation of these indices was found to be an important procedure to reduce measurement discrepancies from baseline comparison. Extending this further was the correlation of these parameters to pulse propagation time from actuator to sensor positions to generate a tomographic representation of the damage in the scanned material. These damage evaluation processes were investigated in an ultrasonic health monitoring system inspecting carbon fibre reinforced composite panels with simulated delamination. The imaging results displayed positive damage characterisation capabilities for implementation within the methodology of smart or intelligent materials.

Abstract: °Abstract. In order to develop new cathodes for reduced temperature SOFCs, Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3-δ-Ag composite cathode was investigated in intermediate-temperature Solid Oxide Fuel Cells (IT-SOFCs). The XRD results suggested that no chemical reactions between BSCF and Ag in the composite cathode were found. The resistance measurements showed that the addition of Ag into BSCF improved electrical conductivity of pure BSCF, and the improved conductivity resulted in attractive cathode performance. In addition, electrochemical impedance spectra exhibited the better performance of BSCF-Ag composite cathodes than pure BSCF, e.g., the polarization resistance value of BSCF-Ag was only 0.36Ω cm² at 650°C, which was nearly 80% lower than that of BSCF electrode. Polarization curves showed the overpotential decreased with the addition of Ag. The current density value of BSCF-Ag was 0.88Acm^-2 under –120mV, about five times of that BSCF measured at 650°C. As a summary, compared to a pure BSCF cathode, it was found that adding Ag in the cathode enhanced the BSCF performance significantly.

Abstract: Solution of two-dimensional stress problem is reduced to integration of bi-harmonic equation[1].A polynomial is chosen as Airy’s stress function.Constants of the polynomial[2] are found by fulfilling the boundary conditions. Stress solutions are obtained from.The paper presents polynomial based stress solutions of beams for complex cases involving offset loads and other combinations with offset loads.The results are compared with those obtained from finite element analysis[3] and conventional methods.The results are in good agreement with each other.

Abstract: The 200L oil drum is widely applied as a result of its various aspects superior performance, implementation of 200L oil drum implementation circulation use may reduce the production cost, reduces the environment pollution and the resources waste, therefore the 200L oil drum's circulation use has the enormous prospect. Based on the oil drum orthopedic, outside surface clean, internal surface clean, drying four critical processes, this article has developed the 200L oil drum circulation use mechanization production line. This production line has made significant improvements on the production technology and automation. The device will not only improve the quality of the renovation of oil drums but also improve production safety.

Abstract: The screw of the helical face is used widely. But the lower precision and the interference are the questions for the perplexing screw. The problems of the conjugate limits and the conditions of involving as milling the helical face and the characteristic of the contact line are discussed. These provide the basis math model for the milling cutter design and these provide the theoretical basis for the parameter selection when the cutter is damped.

Abstract: Due to increased individuation of user needs and market globalization, the demands for product performance have diversified. However, a diversified performance is difficult to be obtained a unique design solution (design value). In a previous study, the robust design method (RDM), which ensures products with a robust performance under diverse conditions, was improved. This method was used to evaluate performance robustness with respect to an adjustable control factor (ACF), which is a factor that can be adjusted by the user. Unfortunately, the RDM is not applicable to design problems that have several ACFs due to the increased calculation amount. To resolve this issue, this study improves the previous method by applying a genetic algorithm and a method to extract the values of ACFs employed in the robustness calculation. The improved RDM was applied to two numerical examples to confirm its effectiveness.

Abstract: According to the microstructure defects of laser claded nickel alloy, such as crack and nets brittle phase, the friction stir processing (FSP) method is utilized in this paper to modify microstructure defects by the coupled effect of thermal and stress of FSP. For this purpose, two key scientific problems of large deformation condition and microstructure evolution theory during FSP, are proposed in this paper. Based on this, the following issues are highlighted in this work. Firstly, obtain the friction condition of larger deformation by continuous dirved friction experiment. Secondly, study on the temperature (T), stress (σ), and strain velocity under different processing parameters via self-developed physical simulation apparatus. Thirdly, disclose the effects of T、σ、 on the microstructure evolution and then obtain the microstructure evolution equation by dynamic re-crystallization. The above work could provide theory support for the new technique of laser cladding and FSP for preparing high performance coating.