Advanced Materials Research Vols. 328-330

Abstract: This paper measured the vibration transmissibility of several honeycomb paperboards and the attenuation coefficient. Laboratory was used to determine the natural frequency of the thickness of 10mm, 20mm, 30mm, 40mm Honeycomb Paperboard. The test results show that the honeycomb paperboard resonance frequency decreases with increasing thickness, while the vibration transmissibility increases with increasing thickness. We have also established finite element model of honeycomb paperboard to simulate its vibration properties. The result of simulation is in good coincidence with the experimental result. In addition, some cases can use computer simulation instead of laboratory testing to obtain the natural frequencies of honeycomb paperboard.

Abstract: This paper presents the inversion power-supply control system with the software of dual SPWM modulation system and voltage closed loop PI control strategy and the hardware foundation of DSP TMS320LF2407A. Aiming at the requirements of rapidity of system, it adopts the feedforward and amplitude control strategy on aspect of control strategy to reduce the dynamic response error. Aiming at the requirements of stability and stationarity, it takes the segmentation intelligent PI control strategy. In order to avoid the system oscillation caused by the input direct current voltage fluctuation, it designs the voltage sluggish loop in the software. It has significant effects in improving the inversion wave form, anti-interference and anti-bias magnet, ensuring the stability of system, reducing the harmonic wave and undesired sound, and improving the wave form quality and the adaptation to load, etc.

Abstract: Metal detector is used more and more widely in the modern social life, it acquires much attention because of its powerful detection capabilities. This article introduces the design and implementation of an intelligent metal detector which is based on TMS320LF-2407.Adopt giant magneto resistive (GMR) sensor with the type of AA006-02. Describe the hardware component, software design, working principle and main functions of the system in detail. The core of the whole contains the probe design and control circuits. The probe: oscillator circuit is constituted by the 555 timer, it provide the sine wave signal for the coil. The control circuits: the signal which is collect by the GMR sensor is processed by voltage amplifier and filtering circuit, the peak detection circuit and A / D conversion, The signal can accurately reflect the characteristic parameters of the received signal, stability, and can eliminate interference.Practice shows that this metal detector with the method can greatly reduce the malfunction rate on the base of meeting the sensitivity.

Abstract: Newton-Raphson (N-R) method has been employed to solve the system of simultaneous equations arising in Rigid-Plastic finite element simulation. The combination of the improved rotative mid-point mensuration and the N-R method, named the M-P method is designated to solve the equations of velocity increment in Rigid-Plastic FEM. The CPU times required for calculation by the M-P method and the N-R method are compared and it is found that the CPU time required for calculation of the N-R method is more than the M-P method. The calculated rolling forces by the M-P method and the N-R method are compared and it is found that the former correlates better with the measured value. Numerical tests and application show that the M-P method is feasible and steady.

Abstract: Cumulative fatigue damage is an important consideration in determining the fatigue life of structures. A cumulative linear damage rule cannot provide a reasonable explanation for cumulative fatigue damage, but a damage curve method based on nonlinear cumulative fatigue damage model can give a reasonable explanation. In this paper, a specific mathematical model is put forward, which is based on the damage curve method. In the model, miner formula is modified properly and an exponent formula is give out to fit the damage accumulate. According to a two-step fatigue test of aluminum–alloy welded joint, the comparison between the calculated results and the testing results is less than 5%. It shows that the model is reasonable and accuracy.

Abstract: An extensive investigation of electromagnetic properties has been carried out on the CeO₂-doped NiZn ferrites, (Ni_0.44Zn_0.56Fe₂O₄), prepared by solid-state reaction technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), and LCR meters were used to analyzed the ceramic phase, microstructure, permeability, permittivity, and quality factor. The results show that the real dielectric constant increases by proper amount of CeO₂ substitution, and the magnitude of this increase is not linear with the content of CeO₂. Initial permeability decreases with the increasing Cerium content. The quality factor reaches the maximum value (194 at 1 MHz) when the added CeO₂ content is 2.0 wt%. CeO₂ substitution increase the resistivity of NiZn ferrites.

Abstract: Because of the complicated shape of the structural characteristics of the tool and the use of performance requirements, the tool substrate pretreatment, deposition equipment and deposition process, diamond film after film substrate adhesion test and tool evaluation has its own peculiarities. Currently, study on the complex shape of diamond coated tools At home and abroad is still in its infancy, and the further study complicated shape for the deposition of diamond coatings on cutting tools and milling properties of adhesion is even more lacking towards to complex shapes for the structural characteristics of diamond coated tool and use requirements. In this paper, it will use the WC-Co (YG6) PCB carbide cutter (STARBIDE455060, diameter 6.35mm) as the matrix material and use the milling testing of glass fiber reinforced composite to assess the adhesion of diamond coated tools and milling performance.

Abstract: The method of using microwelding machine to fabricate micro features on a stainless steel micro mould has been studied. The micro features obtained from molding using an ultrasonic microwelding machine have shown distinctive characteristics. The microflow behavior of polymer melt during the microwelding process is also studied. The micro molds of 0.2mm thick and through holes of 0.05mm and 0.2mm in diameters were used. Results show micro features can be produced using the microwelding machine with molding speed comparable to that of micro injection molding.

Abstract: The bonds of T2 copper/50steel were studied by inertial radial friction welding techniques at different conditions. Ultrasonic C-scan testing was employed to evaluate the bonding situation. In order to verify the reliability of ultrasonic C-scan testing results, the optical microscope, SEM and shear test were used to analyse the microstructure and mechanical properties. It was found that ultrasonic C-scan testing was useful to evaluate the inertial radial friction welding joint situations by analyzing the ratio of good bonded area in the bond area of ultrasonic C-scan images. And the correctness of ultrasonic C-scan testing was testified by microstructure examination. Furthermore, it was concluded that enough metalline plastic deformation occurred, oxide film of joint was destroyed and constituent elements were mutually diffused sufficiently, when two stage pressure was employed and friction pressure 78 MPa, friction speed 3200r/min were used.

Abstract: Surface mulch is regarded as an effective manner to reducing soil water evaporation, but limited with the adverse influence of plastic film mulch on agro-ecosystems. In this paper, liquid films were prepared with the foundation of kelp as a bio-material. The results showed that the films prepared with the mixture of kelp and polyvinyl alcohol (PA) had superimposed layering structure with tiny pores and gaps, and were stable as well as degradable under field water conditions. The results of the simulative experiments with both of aquic sand-loamy soil and yellow silt-loamy soil that mulching with the film of the mixture of kelp and polyvinyl alcohol (PA) could significantly (P<0.01) reduce water evaporation from soil. It was also found that mulching with the liquid films could increase the water retention capacity of the tested soils. As the initial material – kelp is available, the application of the developed liquid film based on kelp for efficient soil moisture management in agricultural production should be recommended.