• Title/Summary/Keyword: internal structure

Search Result 3,006, Processing Time 0.028 seconds

Structural Integrity Assessment of the Internal Structure (원전 기기 내부구조물에 대한 구조건전성평가)

  • Lee, Han-Hee;Choi, Jin-Young
    • Proceedings of the KSME Conference
    • /
    • 2007.05b
    • /
    • pp.3497-3500
    • /
    • 2007
  • The internal structure is subjected to dynamic analysis due to the structural integrity. The internal structure shall be installed in the vertical hole call IR1 of reactor core. In order to verify the deflection of the internal structure, the mode and response spectrum analysis of the internal structure was performed. The natural frequency of the internal structure is 11.6 Hz(mode 1 and 2) and deflections of the internal structure are less than values of allowable design (3.2 mm).

  • PDF

Influence of external structure and internal stacking on wind load characteristics of large-span spherical shell structure

  • Xiaobing Liu;Anjie Chen;Qun Yang;Bin Feng;Xuedong Tian
    • Wind and Structures
    • /
    • v.39 no.3
    • /
    • pp.191-205
    • /
    • 2024
  • To investigate the wind load characteristics of a large-span spherical shell structure, a rigid model pressure test was conducted in a wind tunnel laboratory. The study aimed to examine the impact of various external structures and internal stacking forms on the wind loads of a spherical shell structure in a practical engineering project. This project features two adjacent spherical structures, each spanning 130 m and standing 67 m tall. These two structures are connected by trestles and a transfer station. Variations in the shape factor and the integral force coefficient of the structure were compared and analyzed under different test cases. The results indicate that when two structures are arranged in series, with the adjacent structure positioned upstream, the shape factor of the structure is most affected, resulting in a significant reduction effect at the bottom of the windward surface. Compared to the external structure, the impact of various internal stacking forms on the shape factor of the structure is relatively weak. The adjacent structure significantly improves the wind resistance of the main structure. The integral force coefficient of the structure reaches its peak when internal stacking is full and is at its lowest when there is no internal stacking.

Internal Structure of Information Packages in Digital Preservation

  • Lee, Seungmin
    • Journal of Information Science Theory and Practice
    • /
    • v.2 no.4
    • /
    • pp.6-19
    • /
    • 2014
  • The description of preserved resources is one of the requirements in digital preservation. The description is generally created in the format of metadata records, and those records are combined to generate information packages to support the process of digital preservation. However, current strategies or models of digital preservation may not generate information packages in efficient ways. To overcome these problems, this research proposed an internal structure of information packages in digital preservation. In order to construct the internal structure, this research analyzed existing metadata standards and cataloging rules such as Dublin Core, MARC, and FRBR to extract the core elements of resource description. The extracted elements were categorized according to their semantics and functions, which resulted in three categories of core elements. These categories and core elements were manifested by using RDF syntax in order to be substantially applied to combine metadata records in digital preservation. Although the internal structure is not intended to create metadata records, it is expected to provide an alternative approach to enable combining existing metadata records in the context of digital preservation in a more flexible way.

A Study on Thermal Insulator Effect for Structure Design of Internal Support on Cryogenic Vessel (단열재가 극저온 용기의 내부지지대 구조설계에 미치는 영향)

  • Kim, Doo-Ho;Ji, Hyun-Jin;Kim, Ki-Youl;Cho, Sung-Baek
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.14 no.3
    • /
    • pp.524-531
    • /
    • 2011
  • The cryogenic vessel, storing a liquified solutions as LOX and $LN_2$, consists of a external vessel, internal vessel, thermal insulator and internal support. The internal support should be satisfied with mechanical strength not only to support weight of internal tank but also to maintain uniform space between external and internal tank in spite of external mechanical shock. However, excessive structure design of internal supports is able to increase the amount of heat conduction and the rate of vaporization. The thermal insulator, filled with space between a external and internal vessel, reduces the rate of heat transfer and guarantees the standing time of cryogenic vessel. Especially powder type of insulator has low thermal conductivity and reduce the specification of structure design. In order to evaluate the effect of insulator on structure design, the experiment set-up simulated cryogenic vessel was tested in shock environment according to thermal insulator. As a result, the behavior of internal support under external shock was understood and the design criteria was able to be suggested.

Progressive Collapse Analysis of Reinforced Concrete Core Structure Subjected to Internal Blast Loading (내부 폭발하중을 받는 철근콘크리트 코어의 연쇄붕괴 해석)

  • Kim, Han-Soo;Ahn, Jae-Gyun;Ahn, Hyo-Seong
    • Journal of the Korea Concrete Institute
    • /
    • v.26 no.6
    • /
    • pp.715-722
    • /
    • 2014
  • In this paper, internal blast effect of reinforced concrete core structure were investigated using Ansys Autodyn, which is a specialized hydrocode for the analysis of explosion and impact. It is expected that internal blast case can give additional damage to the structure because it causes rebound of blast loads. Therefore, in this paper, the hazard of internal blast effect is demonstrated using UFC 3-340-02 criteria. In addition, analysis result of Autodyn, experimental result regarding rebound of blast load, and example of UFC 340-02 are compared to verify that Autodyn can analyze internal blast effect properly. Furthermore, progressive collapse mechanism of core structure which is one of the most important parts in high rise buildings is also analyzed using Autodyn. When internal blasts are loaded to core structure, the core structure is mostly damaged on its corner and front part of core wall from explosives. Therefore, if the damaged parts of core wall are demolished, progressive collapse of the core structure can be initiated.

Effect of bidirectional internal flow on fluid.structure interaction dynamics of conveying marine riser model subject to shear current

  • Chen, Zheng-Shou;Kim, Wu-Joan
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.4 no.1
    • /
    • pp.57-70
    • /
    • 2012
  • This article presents a numerical investigation concerning the effect of two kinds of axially progressing internal flows (namely, upward and downward) on fluid.structure interaction (FSI) dynamics about a marine riser model which is subject to external shear current. The CAE technology behind the current research is a proposed FSI solution, which combines structural analysis software with CFD technology together. Efficiency validation for the CFD software was carried out first. It has been proved that the result from numerical simulations agrees well with the observation from relating model test cases in which the fluidity of internal flow is ignorable. After verifying the numerical code accuracy, simulations are conducted to study the vibration response that attributes to the internal progressive flow. It is found that the existence of internal flow does play an important role in determining the vibration mode (/dominant frequency) and the magnitude of instantaneous vibration amplitude. Since asymmetric curvature along the riser span emerges in the case of external shear current, the centrifugal and Coriolis accelerations owing to up- and downward internal progressive flows play different roles in determining the fluid.structure interaction response. The discrepancy between them becomes distinct, when the velocity ratio of internal flow against external shear current is relatively high.

Characteristic of Wind Pressure Distribution on the Roof of Hyperbolic Paraboloid Spatial Structures (쌍곡선포물선 대공간 구조물의 측벽개구율에 따른 지붕의 풍압특성)

  • You, Jang-Youl;You, Ki-Pyo
    • Journal of Korean Association for Spatial Structures
    • /
    • v.13 no.1
    • /
    • pp.51-57
    • /
    • 2013
  • There can be diverse causes in the destruction of a large space structure by strong wind such as characteristics of construction materials and changes in internal and external wind pressure of the structure. To evaluate the wind pressure of roof against the large space structure, wind pressure experiment is performed. However, in this wind pressure experiment, peak internal pressure coefficient is set according to the opening of the roof in Korea wind code. In this article, it was tried to identify the change of internal pressure coefficient and the characteristics of wind pressure coefficient acting on the roof by two kinds of opening on the side of the structure with Hyperbolic Paraboloid Spatial Structures roof. When analyzing internal pressure coefficient according to roof shape, it was found that minimum (52%) and maximum (30%~80%) overestimation was made comparing to partial opening type proposed in the current wind load. It is judged that evaluation according to the opening rate of the structure should be made to evaluate the internal pressure coefficient according to load.

Comparison on Terror Risk of Large Space Structures and High-rise Buildings in Korea (국내 대공간 건축물과 고층 건축물의 테러위험도 비교)

  • Song, Jin-Young;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
    • /
    • v.16 no.1
    • /
    • pp.105-113
    • /
    • 2016
  • Since the 1980s, the number of large space buildings in Korea has consistently been increasing due to large scale international competitions such as the Olympics and the World Cup, demands for environmental improvement, and development of structural systems. Due to these reasons, this paper conducted a comparative analysis on terrorism risk factors of large space structure and skyscrapers in Korea. The results suggest that the total risk level of high-rise and large space structure was "medium level risk" and that the terrorism risk level for large space structure was as high as that for high-rise buildings. As it relates to the risk levels depending on scenarios, terrorism risks to large space structure were higher than high-rise buildings in the "internal explosion" and "internal intrusion" categories. And the results of analyzing explosion-related scenarios except for CBR suggest that terrorism risks to large space structure were highest when it comes to Internal-Explosive followed by Internal-Intrusion and Explosive-Zone I; and the results showed a regular pattern. On the other hand, in the case of high-rise buildings, terrorism risks were highest in Internal-Explosive followed by Explosive-Zone I and Explosive-Zone II; and the results showed an irregular pattern.

Relation between Information Structure and Clause Internal Pauses in the Spontaneous Discourse in Korean

  • Yune, Young-Sook
    • Speech Sciences
    • /
    • v.12 no.4
    • /
    • pp.129-139
    • /
    • 2005
  • This paper investigates any possible correlation between the information structure and the occurrence of clause internal pauses in the spontaneous discourse. One of the possible functions of pause is its capacity to signal the information structure of the discourse. However, this aspect was not much explored in Korean spontaneous speech. In the present study, information structure of spontaneous speech was defined for each word or word group on the basis of the information structure analysis model proposed by Van Donzel (1999) and Roulet (1991, 1997). Thus, at a local level (words or word groups) of discourse structure, a distinction was made between three types of information, new, given and inferable. The results showed that clause internal pauses tend to appear more frequently before new information than other types of information. However compared to the total number of words or word groups it was not noticed any specific ordering concerning different kind of information status and pausing. It was however found that clause internal pauses did not appear randomly. The majority of them occurred at the initial part of the clause or the sentence. This tendency was mostly related to the division of sentence (or clause) into topic and comment. Thus, the role of pauses as a marker of information structure seems to be less effective in spontaneous discourse.

  • PDF

The Internal Structure of an Identification Function in Korean Lexical Pitch Accent in North Kyungsang Dialect

  • Kim, Jungsun
    • Phonetics and Speech Sciences
    • /
    • v.5 no.1
    • /
    • pp.91-98
    • /
    • 2013
  • This paper investigated Korean prosody as it relates to graded internal structure in an identification function. Within Korean prosody, variants regarded as dialectal variations can appear as different prosodic scales, which contain the range of within-category variations. The current experiment was intended to show how the prosodic scale corresponding to the range of within-category differences relates to f0 contours for speakers of two Korean dialects, North Kyungsang and South Cholla. In an identification task, participants responded by selecting an item from two answer choices. The probability of choosing the correct response from the two choices was computed by a logistic regression analysis using intercepts and slopes. That is, the correct response between two choices was used to show a linear line with an s-shape presentation. In this paper, to investigate the graded internal structure of labeling, 25%, 50%, and 75% of predicted probability were assessed. Listeners from North Kyungsang showed progressive variations, whereas listeners from South Cholla revealed random patterns in the internal structure of the identification function. In this paper, the results were plotted using scatterplot graphs, applying the range of within-category variation and predicted probability obtained from the logistic regression analyses. The scatterplot graphs showed the different degree of the responses for f0 scales (i.e., variations within categories). The results demonstrate that the gradient structures of native pitch accent users become more progressive in response to f0 scales.