This paper presents the structural model development and verification processes of wind turbine blade. The National Renewable Energy Laboratory (NREL) Phase VI wind turbine which the wind tunnel and structural test data has publicly available is used for the study. The wind turbine assembled by blades, rotor, nacelle and tower. The wind blade connected to rotor. To make the whole turbine structural model, the mass and stiffness properties of all parts should be clear and given. However the wind blade, hub, nacelle, rotor and power generating machinery parts have difficulties to define the material properties because of the composite and assembling nature of that. Nowadays to increase the power generating coefficient and cost efficiency, the highly accurate aerodynamic loading evaluating technique should be developed. The Fluid-Structure Interaction (FSI) is the emerging new way to evaluate the aerodynamic force on the rotating wind blade. To perform the FSI analysis, the fluid and structural model which are sharing the associated interface topology have to be provided. In this paper, the structural model of blade development and verifying processes have been explained for Part1. In following Part2 paper, the processes of whole turbine system will be discussing.
As the world energy consumption grows, the interest in marin energy resources is increasing. In excavating such resources, the marine riser which connects the floating structure and sea bed is an essential device. The riser system is often exposed to harsh ocean environment and thus vulnerable to damage. Since the failure of the riser system may cause serious economical loss as well as environmental problem, the structural integrity of the riser is very important. Generally, the riser is an extremely slender structure with a much smaller diameter than a length. Therefore, a structural integrity monitoring methodology for typical buildings and bridges may not be applicable. In this paper, the applicability of a damage identification method for a structure to a marine riser is examined via a numerical example. Also, recent research practices and findings for monitoring the behavior and the structural integrity of the marine riser are examined and summarized.
An experimental study on the structural behavior of connection types between approach slab and integral abutment has been done for three typical bar connections. Typical hinge style reinforcing bar detail for its connection is preferred in order to accommodate rotation of the approach slab among engineers. However, the straight horizontal bars can be used as connection detail accomodate structural capacity. Total six specimens with three types of rebar detail are tested for direct tensile and bending load. The characteristic structural behaviors are carefully monitored and all the strain gauge data obtained are analyzed. It is shown that the structural performance of all the specimens well exceed its design allowance. Several design suggestions are given based on careful reviews on the experiment.
PURPOSES: Daejeon is basically divided into an old downtown and a new downtown, and the recent relocation of the Chungcheongnam-do Provincial Government of Republic of Korea from the old downtown and the opening of governmental buildings in the new downtown as well have made this new downtown only densely populated with industrial and business facilities. Such changes in the downtowns have promoted the conditions of the new downtown while, consequently, dragging down the old downtown. Out of concern for those unbalanced developments of the two downtowns, Daejeon is now carrying out several city projects to revive the old downtown. In the light of that, as a part of the project to promote the old downtown, this study aims to conduct an evaluation on landscape of the culture and arts street in Daeheungdong which was built upon those ideas of a theme street project by Daejeon. METHODS: Based on the findings from the questionnaire not only on the components that would design the streetscape of the culture and arts street but also on the public satisfaction with the streetscape, the study defined how those changes in the components affect emotional factors of the pedestrians. In order to achieve the research goal, the study made changes in D/H ratio of the street structural components as well as the roadside trees. In terms of the questionnaire method, the study used the SD scale, and proceeded with its investigation through the frequency analysis, the principal component analysis (the factor analysis) and the structural equation model. RESULTS : According to the results from the factor analysis and the regression analysis, of those three factors, such as the openness, the comfortable sensation and the safety, the openness followed by the comfortable sensation and the safety was determined to have the most positive influence on the total satisfaction. The structural model analysis reported that the D/H and the structural components of the roadside trees and planting have a positive effect on the emotional image, and this emotional image also appeared to be positively related to the total satisfaction. CONCLUSIONS : This study looked into how the changes in the street structural components of the culture and arts street in Daeheungdong would affect the satisfaction with the streetscape, and finally confirmed that the D/H and the planting are what would have a positive effect on this satisfaction. What has been learned from this study will be the basic data to figure out how to promote and improve the culture and arts street in Daeheung-dong as this data will also help designing and developing of those specialized streets in other regions.
Pt nanopowder-dispersed SiO2 (SOP) films were prepared by RF co-sputtering method using Pt and SiO2 targets in Ar atmosphere. The growth rate and Pt content in the film were controlled by means of manipulating the RF power of Pt target while that of SiO2 was fixed. The roughness of the film was increased with increasing the power of Pt target, which was mainly due to the increment of the size and planar density of Pt nanopowder. It was revealed that SOP film formed at 10, 15, 20 W of Pt power contained 2.3, 2.7, and 3.0 nm of spherical Pt nanopowder, respectively. Electrical conductivity of SOP films was exponentially increased with increasing Pt power as one can expect. Interestingly, conductivity of SOP films from Hall effect measurement was greater than that from DC I-V measurement, which was explained by the significant increase of electron density.
Osmia cornifrons plays a major role in the pollination of orchards, but basic information on vitellogenin and the oocyte development is limited. To better understand vitellogenin in hymenopteran insects, we cloned a cDNA encoding vitellogenin from the hornfaced bee O. cornifrons. O. cornifrons vitellogenin cDNA contains 5477 bp with an open reading frame of 1,783 amino acid residues, and has a predicted molecular mass of approximately 200.21 kDa and a pI of 6.55. O. cornifrons vitellogenin possesses four consensus (RXXR/S) cleavage sites and has conserved DGXR and GL/ICG motifs in the C-terminus. The deduced amino acid sequence of the O. cornifrons vitellogenin cDNA showed a 66% identity with Megachile rotundata, 53% to Apis mellifera, 51% to Bombus ignitus, and 42%-30% with other hymenopteran insect vitellogenins. Phylogenetic analysis showed that O. cornifrons vitellogenin clustered with vitellogenins from Megachildae, Apidae, Vespidae, and Formicidae species but not with those from Pteromalidae, Aphelinidae or Ichneumonidae species.
In insect exoskeleton/cuticle, structural cuticular proteins (CPs) and the polysaccharide chitin are the major components of the procuticle. CPs are cross-linked by quinones or quinone methides produced by the laccase2 (Lac2)- mediated oxidation of N-acylcatechols. We reported that two major CPs, TcCPR27 and TcCPR18, belong to the CPR family that contain the RR-2 consensus motif (Rebers & Riddiford), are essential for formation and stabilization of the rigid cuticle of Tribolium castaneum adults. In this study, we characterized and investigated functions of the third most abundant protein, TcCP30, in extracts of elytra. TcCP30 cDNA encodes a protein with 171 amino acid residues containing a putative signal peptide. Unlike TcCPR27 and TcCPR18, TcCP30 mature protein lacks an RR motif, with a very unique amino composition, 36% Glu, 21% His, 20% Arg and 16% Gly. TcCP30 gene is highly expressed right before and after eclosion (in 5 d-old pupae and 0 d-old adults). Immunohistochemical studies revealed that TcCP30 protein was present in rigid cuticle such as elytra and ventral abdomen but not soft cuticle such as hindwings and dorsal abdomen of adult T. castaneum. Injection of dsRNA for TcCP30 into late instar larvae had no affect on larval and pupal growth and development. However, the subsequent pupal-adult molt, more than 50% adults were unable to shed their exuvium and died entrapped in their pupal cuticle. In addition, the resulting adults exhibited wrinkled, warped and split elytra. TcCP30-deficient adults could not fold their hindwings properly because probably due to the malformed elytra. These results indicate that TcCP30 is critical for formation of rigid adult cuticle as well as development and growth of T. castaneum.
Due to rapid urbanization and industrialization, water supply and sewer line systems are also developed relevantly. Manhole is an essential component structure of the pipeline system. Manhole is a structure constructed to accommodate the direction, dimension, differences in level, and easy of maintenance in the pipeline system. In this paper we present the result of investigations pertaining to the structural behavior of PVC sewer manhole buried underground. In the paper mechanical properties of PVC material are reported. In addition, by the finite element analysis (FEA), we confirmed that a PVC double-wall corrugated pipe manhole, when it is buried underground, is safe for the stress as well as buckling strength if the manhole is constructed within the suggested limit of buried depth.
This study investigates area and size of stress part appeared when the continuous loads are applied at artificial joint. Upper and lower parts composed with polyethylene shock absorber and titanium alloy are applied with the loads. The configurations of stress distribution near the hole of support to fix the frame are investigated and secured as through this study. As the result of this study, the stress is concentrated from the edge end of upper artificial joint. The crack is initiated at this point. This analysis result is similar with the instance of tissue corruption due to the damage of artificial joint.
Recently, there are a lot of fires breaking out at special structures. To suppress this fire break down at early stage is very important because it leads to bigger damage in case of special structures. For early suppression, outer wall of building has to be destroyed and need waterproofing for Ignition temperature. So far there is no equipment developed local and all of them are imported from a broad. In this study, In this study, The CAE analysis was the Leading-in of the boom conditions for the development of demolition fire according to the environment of Korea. As a result of this, could be confirmed that decreases stress reduction. maximum 51% to 12% depending on the part. It was possible structural integrity and design. about Telescopic Boom and Outrigger on the basis of this result.
‘In structural system, a certain amount of uncertainties always persists in material properties, geometric parameters and applied loads. In this study, the structure is designed to withstand the uncertainties which are caused by either measurement inaccuracy or system complexity. Random structures are modelled by using ANSYS probabilistic design module. It can be applied easily to any structural system with random parameters. The aim of this paper is to make optimal design for the beam with random input variables due to width and height and response parameters due to displacements and stresses. The probabilistic design is also carried out with ANSYS APDL and then the optimal design is sequentially solved. As the total volume of beam, stresses and displacements at the beam are treated as random parameters, the numerical results are obtained.'
The stone pagoda of Mireuk temple site is currently restoring through the repairing process. This stone pagoda has the various construction types in the inner and outer space. Therefore, the stress concentration and structural behavior need to be considered through the analysis of various construction patterns. To this end, this study presents the structural modelling and analysis considering the discrete element analysis technique to solve the discontinuum behavior between the stone elements. Also, this study performs the structural performance evaluation through the various design variables for the safety of stone pagoda. Through the analysis results, we can find out the small stress concentration in the several members. But, because the stresses and displacements are relatively small, we can secure the safety of the whole structure.
Main topics in this study is a new structural detail for connection between H-Steel or SRC column and flat plate slab. We carried out to evaluate the punching shear performance of H-steel or SRC column + RC slab system for vertical load and lateral load. From the test results structural characteristics - yield moment, yield rotation, maximum moment, deformation capabilities ect. - are obtained and evaluated. In this paper as a shear reinforcement for supporting region of plate closed stirrup type and shear band are used, and their test results are compared.
Double walled carbon nanotubes (DWCNTs) are considered an ideal model for studying the coupling interactions between different concentric shells in multi-walled CNTs. Due to their intrinsic coaxial structures they are mechanically, thermally, and structurally more stable than single walled CNTs. Geometrically, owing to the buffer-like function of the outer tubes in DWCNTs, the inner tubes exhibit exciting transport and optical properties that lend them promise in the fabrication of field-effect transistors, stable field emitters, and lithium ion batteries. In addition, by utilizing the outer tube chemistry, DWCNTs can be useful for anchoring semiconducting quantum dots and also as effective multifunctional fillers in producing tough, conductive transparent polymer films. The inner tubes meanwhile preserve their excitonic transitions. This article reviews the synthesis of DWCNTs, their electronic structure, transport, and mechanical properties, and their potential uses.
Recently, environmental problems associated with the excessive use of fossil fuel are hot issue throughout the world. As an alternative energy resource, the importance of renewable energy is continuously rising. Especially, growth rate of photovoltaic energy generation is one of the best. In this paper, floating PV generation system made of pultruded fiber reinforced polymeric plastic (PFRP) is discussed. It is well known that PFRP has many advantages such as high corrosion resistance, high specific strength/stiffness, etc. Compared with conventional construction materials. To investigate the structural behavior under flow induced dynamic loading, members and connections of members are tested under cyclic loading. It was found that the structural system is strong enough to resist such a cyclic loading.
To inject CO2 in geological formations, deep wells that penetrate the formations need to be constructed. The seal integrity of deep wells for CO2 leakage are enhanced by annulus cements. By injecting CO2, brine in formations can be carbonated and the potential degradation of annulus cement in the carbonated brine has been brought up. In this paper, Type G oil well cement (OWC) pastes are hydrated for 28 days. Conditions of geosequestration in a sandstone formation at a depth of roughly 1 km, was simulated by bubbling CO2 into a heated vessel containing brine. The hydrated OWC cylindrical specimens were exposed to this environment. Slices of the cement specimen were taken periodically, during and after exposure to quantify degradation progression. The elastic modulus of the specimens was examined prior to and after exposure. After 28 days of exposure, the degraded depth of specimen was measured as 4.137 mm. The elastic modulus of the specimens was measured as 2.2 GPa and 3.2 GPa prior to and after exposure respectively. Considering a composite action in the partially degraded specimen, the elastic modulus of degraded part can be extracted. The results indicated that the difference of elastic modulus in the partially degraded annulus cements could occur a composite action of deep wells subject to axial load and shear cracks would be generated due to the composite action.