Advanced Materials Research Vols. 718-720

Abstract: As a typical cellular solid, the honeycomb core shows an orthotropic behavior in its mechanical properties. Engineering analysis often adopts a homogeneity assumption that honeycomb core is equivalent to an anisotropic continuum. Currently available cellular solid model cannot predict the physical properties of titanium honeycomb core with acceptable accuracy. Therefore, mechanical test must be carried out to obtain the mechanical properties of metallic honeycomb structures. This paper introduces the work on flatwise compression test and out-of-plane shear test on titanium honeycomb core structures in accordance to ASTM C 365-03and ASTM C 273-00. The out-of-plane stiffness and strength for titanium honeycomb cores with incircle diameter of 4.8mm and wall thickness of 0.05mm were obtained.

Abstract: Human respiratory signal provides important information in modern medical care. In daily life, respiratory signal is usually captured under different motion states with the help of Electrical impedance pneumography (EIP). Consequently, the captured signal is easily corrupted by electronic/electromagnetic noise, internal mechanical vibration of the lung and motion artifacts. Because respiratory signal and interferences co-exist in an overlapping spectra manner, classical filtering method cannot work here. In this paper, we present a new signal processing method for eliminating the noise and interferences included in EIP signal, by separating the correlated motion artifacts from the raw EIP and 3-axis Acceleration (ACC) signals, restoring the rough respiration signal from the mixed signal, and further processing using wavelet analysis approach. Results are compared to traditional denosing algorithms by wiener filter, which indicates that the new signal processing method we presented is suitable for EIP signals under the motion states.

Abstract: As a powerful tool for seafloor research, the building of seafloor observation network has great value for ocean research and territory security. The seafloor observation network is consist of three parts: the shore station monitoring center, the main network system and the laser Raman spectroscopy system. As one of the sensor nodes, Raman spectroscopy system can detect multiple anions in water non-destructively. In this paper, a remote communication control subsystem for laser Raman spectroscopy system via seafloor observation network was designed. Based on the TCP/IP protocol, a suit of communication control software was developed. Communication control experiments were performed and the experiments results showed that the software was qualified.

Abstract: The spatial data which acquired by 3D laser scanning is huge, aiming at the iteration time is long with classic ICP algorithm, a improved registration algorithm of spatial data ICP algorithm which based on principal component analysis (PCA) is proposed in this paper (PCA-ICP), the basic principle and steps of PCA-ICP algorithm are given. The experiment results show that this method is feasible and the iterative time of PCA-ICP algorithm is shorter than classical ICP algorithm.

Abstract: In this paper, the measurement conditions of heavy metal enriched on the filter membrane using X-ray fluorescence were talked about. According to the heavy metal enriched on the film, the specific parameters were analysed. Through many experiments, the suitable parameters were decided. In order to excite mainly heavy metal in air, the excitation voltage should be not less than 30kV. The excitation current should be between 20μA and 60μA. The measured distance should be between 4mm and 15mm. The best choice of pulse shaping time is around 6.4μs. These parameters setting should have very good application value in air heavy metal measurement.

Abstract: The effective separation of the multilayer ultrasonic echo is the key for layered defective imaging and feature information identification; it is an urgent bottleneck problem to be addressed in the multilayer ultrasonic echo processing field. In this paper, starting from sound-electric equivalent model of ultrasonic echo, combining with multilayer signal features, a structured sparse model of multilayer ultrasonic is built. Studies have shown that multilayer ultrasonic echo could be characterized as Hankle matrix and Toeplitz matrix separation and recognition model. This can be applied to multilayer ultrasonic stress detection field for metal matrix composites structure.

Abstract: Freely falling of a plate contains very complicated unsteady characteristics. In the past decades, most of the studies focused on the mode and trajectoryofa freely falling plate. In this paper, we use PIV to study the instantaneous flow structure and analyze the force exerted on the plate and the influence of the flow on the motion of the plate. As the Reynolds number increases, the flow structure will be changed from the stable mode to the chaotic mode,and it accompanies with a mode switching of the freely falling plate. However, there is no necessarilycorresponding with the stable flow structure, even for the freely falling plate with a stable mode.

Abstract: This paper presents the tensile experiments of composite stiffened panel with three different stringer cut-out configurations. The strain distribution and delamination of the critical region near the stringer cut-out were studied. The influence from the different stringer cut-out configuration and geometric parameters on the strain distribution and delamination was evaluated via the comparison of experimental data, which can provide useful information to support further research and engineering applications.

Abstract: THz spectral properties between 0.2-1.5THz of beta-endosulfan, one of the persistent organic pollutants (POPs), are investigated based on the THz time domain system. Part of the characteristic absorption peaks are theoretically analyzed by Dmol3 modular program. The experimental results show that the average refractive index of beta-endosulfan in the THz waveband is about 1.005 and characteristic absorption peaks exist at 0.67, 0.80, 1.03, 1.14, 1.26 and 1.46THz. The absorption peaks at 0.67THz and 1.03THz have a good match with the theoretic absorption peak positions which appear at 0.72THz and 1.07THz calculated by Dmol3. The peaks at 0.67THz and 1.03THz may be caused by the torsion in B and C direction of beta-endosulfan crystal lattice, along with the translation in A direction. Compared with the experimental results of alpha-endosulfan, it can be seen clearly that these two isomers have completely different absorption peaks. For further it indicates that terahertz time domain spectroscopy (THz-TDS) has great application value in identifying isomers.

Abstract: To solve the problems of online monitoring system for high-voltage battery pack in series, this paper states the design of a practical interface circuit. The circuit consists of PhotoMOS, MCU and electrical switch. The PhotoMOS controlled by MCU could connect the measuring battery to measuring circuit, meanwhile the other batteries are physically isolated from the measuring circuit, and has no influence to the measuring circuit. This method effectively lowers the complexity of circuit, and improves measurement precision.