Applied Mechanics and Materials Vol. 470

Abstract: Many real complex phenomena are related with Weierstrass-Mandelbrot function (WMF). Most researches focus on the systems as parameters fixed, such as calculations of its different fractal dimensions or the statistical characteristics of its generalized form and so on. Moreover, real systems always change according to different environments, so that to study the dynamical behavior of these systems as parameters change is important. However, there is few results about this aim. In this paper, we propose simulated results for the effects of parameters changeably on the graph of WMF in higher dimensional space. In addition, the relationships between the Hurst exponent of WMF and its parameters dynamically in 2-and 3-dimensional spaces are also given.

Abstract: The issue of carbon emissions by electric vehicle(EV) was studied using life cycle theory, and the work provided decision basis for creating China’s CO2 emission standards for auto. The results show that the carbon equivalent emission of coal-fired generation side per unit electricity consumed by EV is lower than the level of normal passenger car in China, but still higher than the forced limit on auto emission within the EU.

Abstract: The design of foot-bridge is often influenced by natural frequency. Consequently, vibration frequency becomes important. The empirical expressions used to quantify this parameter at the design phase have not been developed enough to give guideline to Korea foot-bridge. This paper is concerned with the frequency of steel foot-bridges. It describes the vibration measurement methods employed for testing structures and presents reliable methods of assessing natural frequency from jumping vibration tests. Data from measurements on 30 structures in Seoul are given. Regression formulas of natural frequency for steel-framed foot-bridges are suggested. Finally, obtained formula is compared with empirical expressions of Seoul Citys guideline and Bachmanns curve.

Abstract: A scientific approach is proposed in this research to investigate a disk on module (DOM) product's activation energy based on experimental data that eliminates subjective experience. This study considers multiple temperature conditions to enhance the accuracy of activation energy estimation. In order to ensure the consistency of failure mode in each temperature scenario, the slopes of Weibul probability plots obtained from the failure data are calculated followed by an examination for parallelism. The estimated life time under normal service condition differs from the results obtained using the industrial standard given activation energy by approximately 42%.

Abstract: This paper proposes an artificial immune system for the economic environmental dispatch (EED) of the hydrothermal power system (HPS), considering non-smooth fuel cost and emission level functions. The artificial immune system (AIS) equipped with an accelerated operation and a migration operation can efficiently search and actively explore solutions. The multiplier updating (MU) is introduced to handle the equality and inequality constraints of the HPS, and the ε-constraint technique is employed to manage the constraints of HPS. To show the advantages of the proposed algorithm, one example addressing the best compromise is applied to test the EED problem of the HPS. The proposed algorithm integrates the AIS, the MU and the ε-constraint technique, revealing that the proposed approach has the following merits – 1)ease of implementation; 2)applicability to non-smooth fuel cost and emission level functions; 3)better effectiveness than the previous method, and 4)the requirement for only a small population in applying the optimal EED problem of the HPS.

Abstract: Oriented matrix analysis (OMA) method of system reliability is discussed. OMA uses an oriented fault graph instead of traditional fault tree model. By defining the specially logic operation and calculating reachability matrix, the cut sets can be formed directly and the minimum cut sets can be derived easily. An example is proposed at last, which verifies the efficiency of the proposed method.

Abstract: The mechanical strengths of self-compacting concrete (SCC) with different strengths and different fibers were investigated. By mechanics performance testing on concrete samples, it shows that the fiber can significantly reduce strength of the self-compacting concrete during curing period. The 28d tensile strength of self-compacting concrete can be improved when steel fiber, polypropylene fiber, or polyethylene fiber were used. Moreover, steel fiber can improve the 28d compressive strength; contrarily, polypropylene fiber and polyethylene fiber can reduce the 28d compressive strength.

Abstract: Rock-filled concrete (RFC) is an innovative dam construction material that has been developed quickly in China since 2003. The concrete is produced by pouring the Self-compacting concrete (SCC) into the voids of large rock chunks, with a minimum size of 300 mm, in a formwork. To date, all the practical applications have shown that using RFC in dam constructions has significant economic and environmental benefits. Total construction cost is reduced due to using large amount of rock chunks, which can amount to roughly 55% of the total volume of RFC. When producing SCC, we make full use of local raw materials (e.g. fly ash, limestone) and optimize mix design based on the simple mini-slump flow tests on pastes to obtain better workability and lower cost. SCC with excellent workability can be obtained even the powder material is limestone powder alone. It is indicated that RFC is a potential and promising material for use in future concrete dams.

Abstract: This article determine the wheel load on the role of piezoelectric vibrator in the way as the low-frequency vibration force through analyzing the wheel load, and the loading frequency is 10Hz;in this paper, combining with asphalt roadbed structural response, we get that the piezoelectric conversion device that between the above layer and the middle layer generate optimal performance adopting the theoretical calculation, a single piezoelectric vibrator can generate the electricity by a 2.62 mJ, what provides a theoretical support for the pavement performance of the piezoelectric material.

Abstract: An artificial climate experiment system was designed and established to study reinforcement corrosion of concrete in splash zone at early stage. The relationship between corrosion potential and mineral admixtures was discussed. The results show that changes of mineral admixtures material will affect the corrosion potential of reinforcing steel in concrete, of which slag is the most obvious.