Advanced Materials Research Vol. 487

Abstract: Thin honeycomb paperboard(THPB) is an emerging carton material instead of corrugated paperboard(CPB) recently, public research results and comparative data have not yet found at present. CPB of flute A is selected as contrast material in the paper since its thickness and density are similar to THPB, then properties of two kinds of paperboard are researched and compared according to test methods of edgewise compressive strength for sandwich structure, flatwise crush strength and edgewise crush strength for corrugated paperboard. The results showed that the compressive capacity of THPB in edgewise compressive, flatwise crush and edgewise crush performance is higher than that of CPB of flute A. THPB can be applied to carton for large and heavy product, especially for the package under multidirectional compression.

Abstract: Purpose, with the application of workbench finite element analysis software, get the analysis results of DVG 850 high-speed vertical machining center via the modal analysis and harmonic response analysis. Use the calculation results for reference, put forward the improved method, and prove the credibility of the simulation analysis by testing DVG 850 prototype.

Abstract: A newly inertial piezoelectric rotary actuator is proposed based on controlling the orderly changes of friction force between the rotator and supporting faces in mechanical way. The dynamic simulation model of the actuator is derived. A prototype small inertial rotary actuator characterized by two symmetric piezoelectric stacks has been fabricated based on the proposed method. The actuator can rotate when it is powered with a square-wave or sine-wave voltage. The experimental and simulation results show that its angular speed is proportional to both the driving voltage’s amplitude and the frequency. The experimental results also show good agreement with the simulation analysis.

Abstract: Gear design is based on the standard gear rack parameter in modern gear design. This makes gear design indirect and passive. However, the standard rack parameters have certain limitations on gear parameters and performances. Some good designs with nonstandard parameters are excluded. In order to meet practical requirements and improve the stress performances, a active gear design method is proposed in this paper. 3D gear modal is designed basing on active design method by PRO/E software. The bending stress of tooth root which is affected by gear shaft and tooth width is analyzed by FEM software ANSYS. This paper has a certain reference value for the gear design with high performance.

Abstract: For the loading capability of structures with cracks, the simply calculational models of structures with triangular and rectangular crack have been established, under considering the local rounded area of the crack tip in this paper. The calculation of limit/shakedown domains has been successfully done based on the method of interior point. The influence of some factors such as crack shape and tip size on the loading limit and shakedown of structure has been analyzed and compared, and the results are the trial foundation of intensive study about crack structures.

Abstract: The images of the simply supported beam in different deformation state captured by digital camera are processed. The polynomial function is used to fit the grey level near the edge of the beam in image. The edge is located by calculating the derivative of the fitting grey level. The identified edges in different deformation states are compared to measure the displacements along the edge of the beam. The second order derivative of the measured deflection curve is calculated to obtain the strain of the beam. The abnormal change in the strain data series is used to identify the damage of the beam. It can be shown in the model test results that the image method used here are useful in structure measurement and damage detection.

Abstract: This paper provided an endoscopic oral observation devices, which combines with IR LED (Infrared Rays Light Emitting Diode) and IR CCD (Charge Coupled Device) image sensor to transfer the images to such monitors as television, computers and other media in order to know the situation immediately. While providing user-friendly software interface, allow the users to more easily observe the situation inside the mouth and save the file for the next patient, and even discuss their problems and the improvement progress with the dentist based on the images. The combination of special coated glass and flexible structured CCD observation pen can replace the traditional mouth mirror used by the dentist; in addition, the user can monitor the oral health under the insufficient light condition.

Abstract: In order to enhance the anti-seismic performance of the frame structure and masonry structure with frame at bottom layer, combined shear wall consisting of frame and gridiron composite wall was proposed in this paper, and shear bearing capacity calculation method for the wall was researched. 1/2 scale frame-sparse gridiron composite walls were tested under reversed cyclic loading. Damage processes, load-bearing capacity and hysteretic curves characters of the walls were analyzed. Based on the experiments and reinforced concrete masonry walls data, the force features and shear resistance mechanism of the wall were analyzed, and general shear bearing capacity formula were put forward, and application methods under different conditions were given at the same time. Comparative analysis between calculation results and test results indicated that the formula was accurate enough, and can be referred to in the new construction and post-quake reconstruction of frame structure or masonry structure with frame at bottom layer.

Abstract: In this paper, buckling analysis was carried out on a super-large storage tank under uniform external pressure or wind pressure with finite element method. The critical pressures and buckling deformation modes are obtained and the effects of wind girders and reinforcing rings are investigated. It is found that the critical external pressure of the tank under uniformly applied external pressure obtained by the eigenvalue method is smaller than that obtained by the nonlinear method. Buckling only occurs on the windward side of the tank under the wind pressure. As strengthened by the wind girders and reinforcing rings at the upper par of the tank, buckling deformations here are much smaller than those at the lower part of the tank.

Abstract: Williams series are developed for mode III cracks, based on which the displacement field is defined in the singular region around the crack tip. The Williams element with generalized degrees of freedom (GDOFs) is proposed for analysis of stress intensity factor (SIF) of mode III crack. The SIF at the crack tip can be evaluated analytically by one of the undetermined constants of the Williams element. The influence of the relative length of the crack on the SIF is investigated. Three important parameters for the Williams element, including the radial scale factor, the number of subelements and the terms of the Williams series, are discussed in detail. Numerical example shows that the Williams element is of accuracy and efficiency.