Applied Mechanics and Materials Vols. 405-408

Abstract: Based on the analysis of movement characteristics of inner disc cutter in tunneling machine cutterhead, a trajectory equation to describe the motion behavior of working edge point of inner disc cutter in the process of tunneling is derived by using the method of space coordinate transformation matrix. The trajectory equation mainly considers the parameters of position variables of disc cutter, cutter radius, cutterhead rotating speed and advance speed.

Abstract: Cutter suction dredgers (CSD) play a major part in the field of dredging engineering in harbors, fairways, and land reclamation. CSD can continuously mine and transport the slop with good quality while CSD can tackle many types of soil. However, even a component failure, which is connected with parts and components of CSD, can result in no working. Thus, it affects the production capacity and efficiency of dredgers seriously. It is necessary to analyze the failure probability of CSD. The method of Fault Tree Analysis (FTA) is applied to analyze the failure probability of CSD. The method uses logical reasoning and builds a fault tree model by analyzing the relationship between the basic, intermediate and top events. Based on fault tree model of a variety of events " and " " or " relationship, we can obtain minimal cut sets of that cause the event to failure. Then, get the basic probability of the event. Finally, we can calculate the probability of the top events. Under experiments, the FTA method can accurately calculate the failure probability of CSD, and deduce in reverse order the key events that cause the top event. The study on the key events can reduce the failure probability of CSD, enhance its reliability and safety, and improve the efficiency and productivity indirectly. It will also lay a foundation for product configuration optimization.

Abstract: Grinding, a technique for removing abrasive materials, is a chip-removal process that uses an individual abrasive grain as the cutting tool. Abrasive material removal processes can be very challenging owing to the high power requirements and the resulting high temperatures, especially at the workpiece-wheel interface. This paper presents a novel system that uses graphite particles impregnated in an aluminum oxide matrix to form a grinding wheel. This study specifically investigated grinding wheels with a graphite content of 0.5 wt%. The new grinding wheel was compared with conventional grinding wheels by comparing the factors of grinding performance, such as surface roughness, morphology, wheel wear ratio, grinding temperature, and grinding forces, when the wheels were used under two different coolant strategiesdry and with minimum quantity lubrication (MQL) using pure water. This study found that there is a considerable improvement in the grinding performance using graphite-impregnated grinding wheels over the performance obtained using conventional grinding wheels. The use of 0.5 wt% graphite provided better surface roughness and topography, lower grinding temperature, and decreased force; in addition, wheel consumption was lower, resulting in extended wheel life.

Abstract: This paper presents the experimental simulation on a prototype of a typical suspended water tank. The experimental results have been compared with numerical simulations by adopting two different models for the evaluation of the dynamic sloshing effects in presence of the seismic actions. The first one is a concentrated mass model, analyzed by the numerical code SAP2000 and the second one is a continuous model analyzed by the numerical code FemLab. The results of the experimental analysis allowed the validation of the numerical modeling and showed the importance to evaluate the dynamic sloshing effects in the design and in the seismic verification of a water tank in seismic areas. The experimental investigation confirms the reliability of the numerical models proposed, by highlighting the validity of the simplified model with concentrated masses for the evaluation of the shear force and the bending moment at the base of the tank. More sophisticated numerical modeling are needed only for the evaluating the stress/strain states generated in the walls of the water tank.

Abstract: A new kind of coupling single-mode fiber-optic sensor is presented and the working theory is discussed. Vibration tests of the sensor are carried out. The vibration experimental system based on cantilever are setup and explained in detail. Dynamic response of coupling single-mode fiber-optic sensor compared with piezoelectric sensor is investigated and the result is excellent. Experimental results show that the coupling single-mode fiber-optic sensor is suitable for vibration measurement practically.

Abstract: The accurate prediction of wellhead pressure in process of hydraulic fracturing is a keypoint to guide the design and construction of the fracturing, and does help in choosing appropriate wellhead equipment and pipeline. This paper calculates the formation breakdown pressure by using a self-made formation stress calculation software, analyzes perforation friction and near-wellbore friction on the basis of Michael theory, eatablishes a model of wellbore friction through Darcy-Weisbach equation and the momentum interaction theory of two-phase flow, and according to the composition of wellhead pressure, makes calculation software which can also analyze the influencing factor of wellbore friction, such as delivery rate, pipe diameter, fracturing fluid density and proppant size. Finally, case analysis verifies the accuracy of the computing method.

Abstract: Small and medium hydropower projects have to be suspended due to various reasons. Paper tries to study it as the perspective of entropy. With systems theory and entropy theory, paper defines the concept of project finance entropy. Through PROT project financing entropy analysis of the causes and mechanisms, it established entropy mathematical model of PROT project financing. And through the model, paper makes a detailed analysis of project financing entropy evolution mechanism.

Abstract: Utilising cost data from a block of medium cost apartments in Sungai Buloh, Malaysia, this pilot study aims to evaluate the cost significant elements (CSE) and their cost contributions (in percentages) to the total building cost (TBC) determined based on the grouping of building elements according to the original bills of quantities (BQ) format and the grouping of building elements according to The Institution of Surveyors, Malaysia (ISM)’s elemental cost analysis (ECA) format. Two separate tabulations following the same steps are made in order to achieve the objective of the study. Each tabulation has information on the total cost of each element, and produces information on ‘Actual Total Bill Value’, ‘Mean Bill Value’, ‘Total Bill Value of CSE’, ‘Number of Total Elements (TE)’, ‘Number of CSE in Total’, ‘CSE/TE (per cent)’, and lastly ‘Total Bill Value of CSE/Actual Total Bill Value’. For both tabulations, it is found that “45.45% to 50.00%” of the total number of building elements has contributed to “78.11% to 83.77%” of the TBC and that the two different groupings of building elements being studied have yielded quite similar results. Nonetheless, further analysis can be done with more data from other similar buildings in the region to obtain statistically reliable results.

Abstract: By selecting the relevant factors affect the real estate price, with the qualitative analysis method to analyze the housing prices changes of Xi'an, and then establish ARMA regression model of the housing price index, found that the factors exist long-run co-integration. In order to better reflect the actual, the government policy as a dummy variable is introduced into the model to make regression results more significantly, showing that government policies play an important role in the control of the impact on real estate prices.

Abstract: The sequence of the technological process of the fabrication of the building materials and components is connected with organization molding process. Forming technology node is enough large organized because of using complex of the technological equipment. The technological semantics of the brought process production can be explained and in further formalized.