PURPOSES: This study is primarily focused on evaluating the effects of the non-linear stress-strain behavior of RAP concrete on structural response characteristics as is applicable to concrete pavement. METHODS : A 3D FE model was developed by incorporating the actual stress-strain behavior of RAP concrete obtained via flexural strength testing as a material property model to evaluate the effects of the non-linear stress-strain behavior to failure on the maximum stresses in the concrete slab and potential performance prediction results. In addition, a typical linear elastic model was employed to analyze the structural responses for comparison purposes. The analytical results from the FE model incorporating the actual stress-strain behavior of RAP concrete were compared to the corresponding results from the linear elastic FE model. RESULTS : The results indicate that the linear elastic model tends to yield higher predicted maximum stresses in the concrete as compared to those obtained via the actual stress-strain model. Consequently, these higher predicted stresses lead to a difference in potential performance of the concrete pavement containing RAP. CONCLUSIONS : Analysis of the concrete pavement containing RAP demonstrated that an appropriate analytical model using the actual stress-strain characteristics should be employed to calculate the structural responses of RAP concrete pavement instead of simply assuming the concrete to be a linear elastic material.
Structural dynamic system involves random variables conditions such as material property, geometric parameters and applied loads. This uncertainties result from the structural parameter are carefully considered the dynamic structural response in displacement, stress, and natural frequencies. The random vibrational system must be designed to withstand a certain amount of the fluctuation with respect to the uncertainties. Harmonic response of a spring-mass system is mathematically modelled with the probabilistic finite element method using the Monte Carlo simulation. The aim of this paper is to find the optimal lowest frequency for the spring-mass system with random input variables and response parameters to the displacements. The probabilistic design is carried out using ANSYS probabilistic design module in a commercial application software and then the optimal design is sequentially solved. An efficient and practical optimal design evaluation method is proposed for the design of the harmonic system. The numerical results are obtained where the next highest frequency of the system and displacements treated as constraints.
The technique of VR and AR utilizing HMD and peripherals was due to launch the products in which the research developers predicting the market magnification satisfy the request of the users in 2016. In the suddenly change game market, because of reflecting global technique and standardization trend, the white paper on Korean games and ICT standardization roadmap published for the development of Korea game industry are important in the decision procedure of the prediction of the game industry and game marketing and technology development and standardization support policy related to the game. In this paper, I analyze the present condition of Korean game industry through published white paper on Korean games and ICT standardization roadmap since 2012 by the year 2016 and suggested the competitiveness strengthening measure of Korean game industry required for the pathfinding of the global game market.
In recent years, single layer latticed domes have attracted many designers and researchers's attention all over the world, because single layer latticed domes as space structure are of great advantage in not only mechanical rationality but also function, fabrication, construction and economic aspect. One of the most important factor, in building of single-layer single-layer lattice spherical dome with 300m span, is to ensure the structural safety. Network pattern of single layer latticed domes can be infinitely taken into account. The typical network patterns are triangle, square, hexagon etc. Especially triangular network pattern has mechanically more advantage than the other network patterns because of having not only a large equivalent shearing rigidity but also a large equivalent bending rigidity and axial rigidity. Among the triangular network pattern, that is, 3 way grid pattern, there are many mechanical differences according to the arranging methods of members. In order to ensure the structural stability of single-layer latticed dome with 3 way grid, designers are required to maintain a constant member length and the member angle. In order to achieve this, it is important to search the member array that the standard deviation of the member lengths and angles is the smallest. This paper is to develop the arrangement of member and to verify its validity for single-layer latticed spherical dome with 300m span.
This paper is a study on the nonlinear behavior of polyhedron curved space roof as building structures of quasicrystal system. The quasicrystal is made up of two kinds of parallel hexahedrons, and all the line elements of the parallelepiped have the same length. The quasicrystal design grid dome has a pentagonal symmetry and all members have the same length. This paper described form of design gird dome, and showed the analysis conditions. Also, The displacement-load curve is shown through the analysis and we grasped the flow of the load and forces through analysis of design grid dome applied quasicrystal system.
The objective of this study is to evaluate the structural safety of the spherical-helical turbine for hydro-power. We analyze fluid-structure interaction of the spherical-helical turbine for hydro-power using ANSYS-CFX and Mechanical. The maximum combined stress, deformation and safety factor of the spherical-helical turbine in cases of three types of materials were obtained by fluid-structural analysis. From structural analysis, the maximum value of the equivalent stress occurred at the shaft of the turbine for three material types. In case of a polyethylene turbine blades, the maximum equivalent stress and safety factor were 3.46 MPa and 7.23. Polyethylene turbine blades were evaluated to be safe except of the turbine shaft. Several researches will be performed based on the results of this study and more research and development of technologies are needed in this field.
The objective of this work is to investigate the A-IMS structural defects on the tubular shaft and solid shaft by analyzing the under-fill, metal flow, effective stress and load characteristics. The tubular shaft and solid shaft were designed 6 stage process by upper and lower die. The results were analysed by using a finite elements analysis method. The coefficient of frictions were set Oil_Cold conditions as referred to the analysis library. It was found that the actual under-fill phenomenon was not observed in both tubular and solid shaft. The load values of tubular and solid shaft were 520ton and 255ton, respectively. These values were under the limit of forging machine maximum value.
Insecticidal toxicities of the isolated constituent of Eucalyptus dives oil and its analogues were bioassayed. 3-Carvomenthenone was isolated by chromatographic techniques and determined by EI-MS, 13C-NMR,1H-NMR, 1H-1H COSY, and HMQC. In the fumigant bioassay against P. interpunctella, cyclohexenone exhibited the strongest insecticidal toxicity (LD50 against larvae and adults, 2.45 and 3.63 μg/cm3), followed by methylcyclohexenone, seudenone, and 3-carvomenthenone. In the structure-activity relationships between 3-carvomenthenone analogues and insecticidal toxicity, the mode of the insecticidal action of 3-carvomenthenone, cyclohexenone, methylcyclohexenone, and seudenone was through the dermal organs of T. castaneum and P. interpunctella. This study indicates that 3-carvomenthenone, cyclohexenone, methylcyclohexenone, and seudenone have potential capacity for the development as safety natural agents to control the stored grain insects.
The purpose of this study was to isolate an active constituent from the essential oil of Eugenia caryophyllata leaves and evaluate its insecticidal activity against Pochazia shantungensis nymphs and adults. According to chromatographic and spectroscopic analyses, the active constituent of E. caryophyllata leaves was identified as eugenol. Based on LC50 values and structural analogues of eugenola gainst the P. shantungensis nymphs and adults, isoeugenol (LC50, 83.29 and 91.03 mg/L) exhibited the highest insecticidal activity, followed by methyl isoeugenol (105.61 and 114.48 mg/L), eugenol (124.44 and 143.24 mg/L), methyl eugenol (126.31 and 143.84 mg/L), and acetyl eugenol (165.11 and 170.06 mg/L). Insecticidal activity against P. shantungensis was dependent on the presence of a functional group in 4-ally-2-methoxyphenol. These results indicate that E. caryophyllata oil and eugenol analogues might be potential alternative synthetic insecticidal agents.