• Title/Summary/Keyword: structural evaluation

Search Result 4,836, Processing Time 0.029 seconds

Relationship between Vocabulary and Design in Design Ideation Process -Focusing on Avant-garde Fashion Design- (디자인 발상 과정에 나타난 어휘와 디자인의 연관성 연구 -아방가르드 패션디자인을 중심으로-)

  • Kim, Yoon Kyoung
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.45 no.4
    • /
    • pp.727-739
    • /
    • 2021
  • The purpose of this study is to present the objective evaluation semantic scale of avant-garde design. Apparel majors were asked to express associative vocabulary, design development, and final design intentions for the avant-garde, and the final 70 copies were used for analysis. The results found the item style was shown often in the order of dress, coat, and combination of shirt and pants. In order, the silhouettes appeared as atypical, complex, square, and triangular; the decorations appeared as feathers, frills, and round sculptures; and the idea method appeared as extreme, association, and removal method. In examining the relations of associative words and idea designs, the dress had relations with associative words such as 'peculiar,' 'futuristic,' 'fancy,' 'Comme des Garcons,' and 'deconstruction.' As for the relationship between the idea design and the expression image vocabulary, it was found that 'one piece' recalled 'huge,' 'volume,' 'abundant,' 'peculiar,' and 'unknown,' while 'coat' recalled 'huge,' 'big silhouette,' and 'padding.' In conducting the word cloud technique, the overall design showed the central keywords were 'huge,' 'big silhouette,' 'unbalance,' 'feather,' 'structural,' 'unknown,' and 'frill,' in order.

Numerical and analytical predictions of nuclear steam generator secondary side flow field during blowdown due to a feedwater line break

  • Jo, Jong Chull;Jeong, Jae-Jun;Moody, Frederick J.
    • Nuclear Engineering and Technology
    • /
    • v.53 no.3
    • /
    • pp.1029-1040
    • /
    • 2021
  • For the structural integrity evaluation of pressurized water reactor (PWR) steam generator (SG) tubes subjected to transient hydraulic loading, determination of the tube-to-tube gap velocity and static pressure distributions along the tubes is prerequisite. This paper addresses both computational fluid dynamics (CFD) and analytical approaches for predicting the tube-to-tube gap velocity and static pressure distributions during blowdown following a feedwater line break (FWLB) accident at a PWR SG. First of all, a comparative study on CFD calculations of the transient velocity and pressure distributions in the SG secondary sides for two different models having 30 or no tubes is performed. The result shows that the velocities of sub-cooled water flowing between any adjacent two tubes of a tubed SG model during blowdown can be roughly estimated by applying the specified SG secondary side porosity to those of the no-tubed SG model. Secondly, simplified analytical approximate solutions for the steady two-dimensional SG secondary flow velocity and pressure distributions under a given discharge flowrate are derived using a line sink model. The simplified analytical solutions are validated by comparing them to the CFD calculations.

Shear strength evaluation of RC solid piers of high-speed railway bridges in China

  • Guo, Wei;Fan, Chao;Cui, Yao;Zeng, Chen;Jiang, Lizhong;Yu, Zhiwu
    • Structural Engineering and Mechanics
    • /
    • v.78 no.4
    • /
    • pp.413-423
    • /
    • 2021
  • Piers are the main lateral force-resisting members of high-speed railway (HSR) bridges used in China and are characterized by low axial load ratios, low longitudinal reinforcement ratios, low stirrup ratios, and high shear span ratios. It is well known that flexural, flexural-shear, and shear failures of piers may occur during an earthquake. In this study, a new shear strength model was developed to simulate the seismic failure of HSR solid piers accurately. First, low cyclic-loading test data of solid piers obtained in recent years were collected to set up a database for model verification. Second, based on the test database, the applicability of existing shear strength models was evaluated. Finally, a new shear strength model for HSR solid piers with round-ended cross-sections was derived based on the truss model and ultimate equilibrium theory. In comparison with existing models, it was demonstrated that the proposed model could be used to predict the shear strength of HSR piers more accurately.

Evaluation on Mechanical Properties of Sintered Tungsten Materials by Solvents (소결된 텅스텐 재료의 용매에 의한 특성 평가)

  • Park, Kwang-Mo;Lee, Sang-Pill;Lee, Jin-Kyung
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.24 no.3
    • /
    • pp.289-294
    • /
    • 2021
  • Tungsten (W) is used as a facing material for nuclear fusion reactors, and it is used in conjunction with structural materials such as copper alloy (CuCrZr), graphite, or stainless steel. On the other hand, since tungsten is a material with a high melting point, a method that can be manufactured at a lower temperature is important. Therefore, in this study, tungsten, which is a facing material, was attempted to be manufactured using a pressure sintering method. Material properties of sintered tungsten materials were analyzed for each solvent using two types of solvents, acetone and polyethylene glycol. The sintered tungsten material using acetone as a solvent exhibited a hardness value of about 255 Hv, and when polyethylene glycol was used, a hardness value of about 200 Hv was shown. The flexural strength of the sintered tungsten material was 870 MPa and 307 MPa, respectively, when acetone and polyethylene glycol were used as solvents. The sintered tungsten material using acetone as a solvent caused densification between particles, which served as a factor of increasing the strength.

The Importance of Brand and Retailer Associations in Evaluating a Product Category Extension

  • Eom, Hyo Jin;Hunt-Hurst, Patricia;Lu, Zhenqiu (Laura)
    • Fashion, Industry and Education
    • /
    • v.16 no.2
    • /
    • pp.30-39
    • /
    • 2018
  • This study investigates the importance of brand and retailer associations when consumers evaluate a product category extension in the context of brand and retailer collaborations. Although brand extensions are considered to reduce costs for introducing a new product category, limited study has focused on the role of brand and retailer associations in the context of brand and retailer collaborations. Using a total of 440 participants, a hypothesized model was tested using a structural equation modeling (SEM). The results show that brand and retailer associations influence the perceived fit between a brand and a retailer. In addition, the image fit and quality fit are significantly related to brand and retailer attitudes as well as brand extension evaluation. Since consumers may use their associations with brands or retailers when they perceive product differentiation, market position, and brand extensions, the role of brand or retailer associations is important to marketers, retailers, and consumers. Given the importance of brand and retailer collaborations as a brand positioning strategy in the global branding and retail setting, the findings of this study contribute to brand and retail management by providing empirical evidence on how consumers perceive new products from extended brands in the marketplace when a brand collaborates with a retailer.

Modal analysis of FG sandwich doubly curved shell structure

  • Dash, Sushmita;Mehar, Kulmani;Sharma, Nitin;Mahapatra, Trupti R.;Panda, Subrata K.
    • Structural Engineering and Mechanics
    • /
    • v.68 no.6
    • /
    • pp.721-733
    • /
    • 2018
  • The modal frequency responses of functionally graded (FG) sandwich doubly curved shell panels are investigated using a higher-order finite element formulation. The system of equations of the panel structure derived using Hamilton's principle for the evaluation of natural frequencies. The present shell panel model is discretised using the isoparametric Lagrangian element (nine nodes and nine degrees of freedom per node). An in-house MATLAB code is prepared using higher-order kinematics in association with the finite element scheme for the calculation of modal values. The stability of the opted numerical vibration frequency solutions for the various shell geometries i.e., single and doubly curved FG sandwich structure are proven via the convergence test. Further, close conformance of the finite element frequency solutions for the FG sandwich structures is found when compared with the published theoretical predictions (numerical, analytical and 3D elasticity solutions). Subsequently, appropriate numerical examples are solved pertaining to various design factors (curvature ratio, core-face thickness ratio, aspect ratio, support conditions, power-law index and sandwich symmetry type) those have the significant influence on the free vibration modal data of the FG sandwich curved structure.

High heat flux limits of the fusion reactor water-cooled first wall

  • Zacha, Pavel;Entler, Slavomir
    • Nuclear Engineering and Technology
    • /
    • v.51 no.5
    • /
    • pp.1251-1260
    • /
    • 2019
  • The water-cooled WCLL blanket is one of the possible candidates for the blanket of the fusion power reactors. The plasma-facing first wall manufactured from the reduced-activation ferritic-martensitic steel Eurofer97 will be cooled with water at a typical pressurized water reactor (PWR) conditions. According to new estimates, the first wall will be exposed to peak heat fluxes up to $7MW/m^2$ while the maximum operated temperature of Eurofer97 is set to $550^{\circ}C$. The performed analysis shows the capability of the designed flat first wall concept to remove heat flux without exceeding the maximum Eurofer97 operating temperature only up to $0.75MW/m^2$. Several heat transfer enhancement methods (turbulator promoters), structural modifications, and variations of parameters were analysed. The effects of particular modifications on the wall temperature were evaluated using thermo-hydraulic three-dimensional numerical simulation. The analysis shows the negligible effect of the turbulators. By the combination of the proposed modifications, the permitted heat flux was increased up to $1.69MW/m^2$ only. The results indicate the necessity of the re-evaluation of the existing first wall concepts.

Analysis on damage of RC frames retrofitted with buckling-restrained braces based on estimation of damage index

  • Liu, Ruyue;Yang, Yong
    • Structural Engineering and Mechanics
    • /
    • v.70 no.6
    • /
    • pp.781-791
    • /
    • 2019
  • Earthquakes most often induce damage to structures, resulting in the degradation or deterioration of integrity. In this paper, based on the experimental study on 5 RC frames with different span length and different layout of buckling-restrained braces, the seismic damage evaluation law of RC frame with buckling-restrained braces was analyzed, and then the seismic damage for different specimens was calculated using different damage models to study the damage evolution. By analyzing and comparing the observation in test and the calculated results, it could be found that, damage evolution models including Gosain model, Hwang model as well as Ou model could better simulate the development of damage during cyclic loading. Therefore, these 3 models were utilized to analyze the development of damage to better demonstrate the evolution law for structures with different layout of braces and under different axial compression ratios. The results showed that from all layouts of braces studied, the eccentrically braced frame behaved better under larger deformation with the damage growing slowly. It could be deduced that the link beam benefited the seismic performance of structure and alleviated the damage by absorbing high values of energy.

An interface model for the analysis of the compressive behaviour of RC columns strengthened by steel jackets

  • Minafo, Giovanni
    • Structural Engineering and Mechanics
    • /
    • v.71 no.3
    • /
    • pp.233-244
    • /
    • 2019
  • Steel jacketing technique is a retrofitting method often employed for static and seismic strengthening of existing reinforced concrete columns. When no continuity is given to angle chords as they cross the floor, the jacket is considered "indirectly loaded", which means that the load acting on the column is transferred partially to the external jacket through interface shear stresses. The evaluation of load transfer mechanism between core and jacket is not straightforward to be modeled, due to the absence of knowledge of a proper constitutive law of the concrete-to-steel interface and to the difficulties in taking into account the mechanical nonlinearities of materials. This paper presents an incremental analytical/numerical approach for evaluating the compressive response of RC columns strengthened with indirectly loaded jackets. The approach allows calculating shear stresses at the interface between core and jacket and predicting the axial capacity of retrofitted columns. A proper constitutive law is proposed for modelling the interaction between the steel and the concrete. Based on plasticity rules and the non-linear behaviour of materials, the column is divided into portions. After a detailed parametric analysis, comparisons are finally made by theoretical predictions and experimental results available in the literature, showing a good agreement.

Fiber element-based nonlinear analysis of concrete bridge piers with consideration of permanent displacement

  • Ansari, Mokhtar;Daneshjoo, Farhad;Safiey, Amir;Hamzehkolaei, Naser Safaeian;Sorkhou, Maryam
    • Structural Engineering and Mechanics
    • /
    • v.69 no.3
    • /
    • pp.243-255
    • /
    • 2019
  • Utilization of fiber beam-column element has gained considerable attention in recent years due mainly to its ability to model distributed plasticity over the length of the element through a number of integration points. However, the relatively high sensitivity of the method to modeling parameters as well as material behavior models can pose a significant challenge. Residual drift is one of the seismic demands which is highly sensitive to modeling parameters and material behavior models. Permanent deformations play a prominent role in the post-earthquake evaluation of serviceability of bridges affected by a near-fault ground shaking. In this research, the influence of distributed plasticity modeling parameters using both force-based and displacement-based fiber elements in the prediction of internal forces obtained from the nonlinear static analysis is studied. Having chosen suitable type and size of elements and number of integration points, the authors take the next step by investigating the influence of material behavioral model employed for the prediction of permanent deformations in the nonlinear dynamic analysis. The result shows that the choice of element type and size, number of integration points, modification of cyclic concrete behavior model and reloading strain of concrete significantly influence the fidelity of fiber element method for the prediction of permanent deformations.