Applied Mechanics and Materials Vols. 548-549

Abstract: ZnO-SiO₂ nanostructures were grown on both bare Si and Pt-coated Si substrates via chemical bath deposition (CBD). The grown nanostructures were characterized using Scanning Electron Microscope with Energy Dispersive X-ray Spectroscopy (SEM-EDS), Fourier Transform Infrared (FTIR) measurement and Ultraviolet-Visible (UV-Vis) absorption spectroscopy. Surface morphology results revealed that Pt-coated Si substrate have promoted the growth of ZnO-SiO₂ nanostructures by providing more active sites for nucleation thus formation ZnO-SiO₂ nanostructures were observed. It is believed that SiO₂ will adhere to the non-polar sides of the grown ZnO nanostructures. This result is manifested in the FTIR spectra which showed a pronounced peak corresponding to ZnO-SiO₂ grown on bare Si suggesting that more Si-O bonds are present. However, Pt-coating did not significantly affect the band gap of the grown ZnO-SiO₂ nanostructures.

Abstract: ZnO nanostructures were successfully grown on electrochemically etched p-type Si (100) substrate via chemical bath deposition method under basic solution. These nanostructures are characterized through scanning electron microscopy – energy dispersive X-ray spectroscopy (SEM-EDS) and ultraviolet-visible spectroscopy (UV-Vis). SEM results revealed that the density of the ZnO nanorods can be controlled by changing the surface morphology of the substrate via electrochemical etching process. At around 200-400 nm, the reflectance intensity of ZnO is significantly decreased as the density of the nanorods increases. Discussion on the possible growth mechanism of ZnO on etched Si during deposition is also presented.

Abstract: Edge-drop control enlarges the shape control theories and technologies. But compared to the profile and flatness control technology, the edge drop control is a developing topic. This paper analyze the influence of strip thickness, strip width, reduction ratio, friction coefficient and deformation resistance on the edge drop based on the elastic deformation of rolls and the three-dimensional plastic deformation of strip for UCMW cold rolling mill. The results will support the further research on the edge drop control for cold rolling mill.

Abstract: The vibration signals of rolling element bearings are non-linear and non-stationary and the corresponding fault features are difficult to be extracted. EEMD (Ensemble empirical mode decomposition) is effective to detect bearing faults. In the present investigation, MEEMD (Modified EEMD) is presented to diagnose the outer and inner race faults of bearings. The original vibration signals are analyzed using IMFs (intrinsic mode functions) extracted by MEEMD decomposition and Hilbert spectrum in the proposed method. The numerical and experimental results of the comparison between MEEMD and EEMD indicate that the proposed method is more effective to extract the fault features of outer and inner race of bearings than EEMD.

Abstract: The background noise makes it difficult to detect incipient faults through vibration analysis. The stochastic resonance (SR) method can be applied to enhance the signal-to-noise ratio (SNR) of a system output using the unavoidable environmental noise. The parameters selection is the most important to generate SR. The proposed fault diagnosis method utilizes the artificial bee colony algorithm to find the best parameters of SR so as to match input signals and detect faults. The performance of the proposed method is confirmed as compared to the fixed parameters method.

Abstract: To deal with the durability analysis of PEM fuel cell, it is necessary to carry out a further understanding of each component response, especially each layer of the MEA. So the main purpose of this paper is to understand the mechanical properties of electrode layer and find out the effect of temperature and the content of catalyst particles on the electrode yield stress. To overcome the experimental limitations, numerical method is used here. A 3-phase model of the electrode is built, which includes a user-defined material with catalyst particles. Due to the porosity of the electrode, the user-defined material is defined as a nafion ionomer glassy constitutive model by bringing in the effect of foam structure. Catalyst agglomerate particles are assumed as isotropic elastic spheres with relatively high Young’s modulus. The yield stress is extracted from the simulation, and the influences of temperature and agglomerate fraction on it are discussed.

Abstract: Parametric finite element model for a commonly used telescopic boom structure of a certain type of truck-mounted crane has been established. Static analysis of the conventional design configuration was performed first. And then an optimization process has been carried out to minimize the total weight of the telescopic structures. The design variables include the geometric shape parameters of the cross-sections and the integrated structural parameters of the telescopic boom. The constraints include the maximum allowable equivalent stresses and the flexure displacements at the tip of the assembled boom structure in both the vertical direction and the circumferential direction of the rotating plane. Compared with the conventional design, the optimization design has achieved a significant weight reduction of up to 24.3%.

Abstract: A novel plasmonic passband filter consisting of metal-insulator-metal perforated with an array of rectangular grooves and circular holes is proposed and demonstrated. The transmission property of the proposed structure is obtained by employing the finite difference time domain with perfectly matched layer absorbing boundary condition. The result reveals that a passband with high transmission can be achieved. And the transmission peak position can be efficiently tuned by changing the factors of the structure, such as the sizes of circular holes and grooves. The proposed filter has potential applications for integrated optoelectronic devices due to its miniaturized size.

Abstract: In this paper, a novel metal structure that integrates double continuous Au films and double aligned gold (Au) non-close-packed ellipsoidal nanoparticle arrays is proposed. The optical features of this structure are simulated by using the three-dimensional finite-difference time-domain (3D-FDTD) method. Bimodal plasmonic resonances with the highest transmission up to 74% and 66% (corresponding to the short and long-wavelength, respectively) are achieved. This proposed structure with sub-wavelength size may provide fascinating applications in optoelectronic devices such as transparent conductors and conductive devices, slow light devices, highly sensitive sensors.

Abstract: Traditional cam profile curve is not changeable after it is made. So it can’t meet the requirement when the follower needs to change the motion within a short time. Therefore, we designed a new cylindrical cam structure whose profile curve could be reconstructed by adjust inserted depth of the chips. We built its three-dimension object model by SOLIDWORKS and explained its advantages and shortcomings. We illustrated its advantages by provided an example of application. And results show the new cam structure is high versatility and convenient to realize the needs of different follower motion by reconstruct its profile.