Advanced Materials Research Vol. 853

Abstract: Diapers become popular and widely used in healthcare during the last few decades. It is critically important in healthcare management to monitor the incontinence conditions of frail elderly. This paper aims to model the wetness-time relationship via scientific experiments by a newly devised wetness sensor and to work out an effective way for the prediction of the volume of urine voided. Physiological saline is used to emulate the urine voiding. This study provides a way for monitoring the incontinence conditions of the elderly and can be used to improve the effectiveness of clinical management system by the application of smart diapers with build-in sensors.

Abstract: This study is aimed at researching surface roughness effect on the performance of blades in terms of aerodynamics. Numerical simulation on a rough flat plate with a row of 35°round film holes under different roughness heights, Reynolds numbers and blowing ratios is conducted to see how they affect film cooling on a flat plate. In terms of aerodynamics, the increase of surface roughness height, Reynolds number and blow ratio will result in the increase of skin friction coefficient. Besides, roughness has combined effects with Reynolds number and blowing ratio So the effect of surface roughness on blades performance is too big to ignore.

Abstract: More and more seismic and log data analysis showed that for high pressure water injection reservoir, the injected water interact with the rock in the process of fluid flowing into reservoir. The pore pressure in rock pores and cracks will be changed, resulting in the change of rock skeleton stress. On the one hand this phenomenon will lead to the changes of reservoir rock physical mechanics properties; on the other hand, it will causes stress redistribution in the vicinity area, and the additional stress may load on the casing which brings out casing damage or causes cracks open or shut-down and fault slip. All of these could result in severe engineering accidents. To analyze the effects of flow field change on corresponding stress field during conventional reservoir development, numerical simulations and theoretical analysis method were combined to study the flow induced stress change of sandstone reservoir during development. The calculated results were compared to each other to validate the correctness of the two models. Analytical solutions and simulation results present the magnitude and orientation of stress and the distribution of differential stress around a single well, and illustrate the change rule of stress field with the variation of flow field. We also illustrate the stress distribution of two wells using numerical simulation results to understand the well interference.

Abstract: Collapsible fabric tank which is an important part of oil equipment equips army with large reserves. The evaluation of collapsible fabric tank storage life, lacking of corresponding test data support, is on the conservative side, which causes manage and storage uncertainty to army. Based on reliability theory, storage life evaluation method of collapsible fabric tank is established. Failure data of collapsible fabric tank under several accelerated stress levels is obtained. According to probability distribution hypothesis test, Weibull distribution has better goodness of fit and life prediction model is obtained. A new maximum likelihood estimation is proposed as statistical analysis method and model parameters are evaluated. Storage life and reliability index of collapsible fabric tank under normal storage temperature are evaluated which brings collapsible fabric tank storage life potential into play and improves use economy.

Abstract: In view of serious degree of mouth formation rock weathering, poor stability, the construction excavation characteristics such as easy to collapse of underground engineering, incision reinforcement technology is used in underground engineering in the mouth period of construction, which changes the mechanical properties of surrounding rock and improves the penetration resistance of surrounding rock. Using three dimensional finite element program (ls-dyna) numerical simulations show that the stratified structure of the grouting tube in the surrounding rock is similar with covering layer thickness steel ball, which makes the projectile yaw in the process of penetration movement. As is shown through comprehensive calculation and analysis, the zero incision reinforcement technology can make the penetration resistance of the underground engineering mouth period increased by 30% ~ 40%.

Abstract: There are several nondestructive testing techniques available to test the compressive strength of the concrete and the Rebound Hammer Test is among one of the fast and economical methods. Nevertheless, it is found that the prediction results from Rebound Hammer Test are not satisfying (over 20% mean absolute percentage error). In view of this, this research intends to develop a concrete compressive strength prediction model for the SilverSchmidt test hammer, using data collected from 838 lab tests. The Q-values yield from the concrete test hammer SilverSchmidt is set as the input variable and the concrete compressive strength is set as the output variable for the prediction model. For the non-linear relationships, artificial intelligence technique, Support Vector Machines (SVMs), are adopted to develop the prediction models. The results show that the mean absolute percentage errors for SVMs prediction model, 6.76%, improves a lot when comparing to SilverSchmidt predictions. It is recommended that the artificial intelligence prediction models can be applied in the SilverSchmidt tests to improve the prediction accuracy.

Abstract: The defects of the lower tooth height and of larger pitch in thread portion of rolled pieces are prone to appearing when rolling thread shaft in cross wedge rolling. To solve this problem, changing the blank shape and size were tried. Two types of concave conical and round blanks are designed with concave conical blanks obtained by rolling in the cross wedge rolling. Because the design of the rolling die is simple, good precision of blank can be ensured. Multiple size types of blanks were designed and the rolling experiment was made in the rolling mill of model H630. By measuring the values of the tooth height and pitch, the effect of blank shape on thread shafts rolled in the wedge rolling were investigated carefully. The reasonable size range of the blank shape was obtained. The conclusions above pave the theoretical foundation for the in-depth study on this technology.

Abstract: Virtual reality provides an easy, powerful, intuitive way of human-computer interaction. The user can watch and manipulate the simulated environment in the same way we act in the real world, without any need to learn how the complicated user interface works. Therefore many applications like flight simulators, architectural walkthrough or data visualization systems were developed relatively fast. Later on, virtual reality has was applied as a teleoperating and collaborative medium, and in the entertainment area. Augmented reality system generates a complex view where the virtual areas are covered by real environment and offers the basic working place for the user. It is a reciprocal combination of the real scene observed by the camera and virtual scene generated by the computer logical core that mixture the both scenes. It is easy to say that possibilities of augmented reality find the utilization in many industrial spheres like as aeronautics, automobile industry, manufacturing etc.

Abstract: The automatic scratch geometrical parameters analysis algorithms based on the images obtained by scanning probe microscopy have been developed. We provide a description of the technique to determine the contact area and the scratch volume with and without account of the pile-ups. The developed algorithms are applied to measure the dynamic hardness by sclerometry on the submicron and nanometer scale.

Abstract: Based on the principle of hand scraping a set of automatic scraping system is designed in this paper. Machine tool bed consists of supporting chassis and cast iron sidewall, which has little deformation, good rigidity and high mechanical strength. And the operating floor features 3-Degree of Freedom with high precision. Guideway adopts imported linear guideway, featuring high precision, high load - bearing redundancy and long life. Scraping tool holder is stably installed in the hole at the end of the piston rod. By the electrical control system the cylinder can control scraping tool to do reciprocal motion stably. Scraping points on the surface of workpieces are captured by a CCD camera with high detection efficiency and accurate test data. The results show that the system is designed to greatly reduce labor intensity and improve scraping efficiency under the precondition of keeping good scraping quality.