• Title/Summary/Keyword: Failure in the continuity

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Improved analytical method for adhesive stresses in plated beam: Effect of shear deformation

  • Guenaneche, B.;Benyoucef, S.;Tounsi, A.;Adda Bedia, E.A.
    • Advances in concrete construction
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    • v.7 no.3
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    • pp.151-166
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    • 2019
  • This paper introduces a new efficient analytical method, based on shear deformations obtained with 2D elasticity theory approach, to perform an explicit closed-form solution for calculation the interfacial shear and normal stresses in plated RC beam. The materials of plate, necessary for the reinforcement of the beam, are in general made with fiber reinforced polymers (Carbon or Glass) or steel. The experimental tests showed that at the ends of the plate, high shear and normal stresses are developed, consequently a debonding phenomenon at this position produce a sudden failure of the soffit plate. The interfacial stresses play a significant role in understanding this premature debonding failure of such repaired structures. In order to efficiently model the calculation of the interfacial stresses we have integrated the effect of shear deformations using the equilibrium equations of the elasticity. The approach of this method includes stress-strain and strain-displacement relationships for the adhesive and adherends. The use of the stresses continuity conditions at interfaces between the adhesive and adherents, results pair of second-order and fourth-order coupled ordinary differential equations. The analytical solution for this coupled differential equations give new explicit closed-form solution including shear deformations effects. This new solution is indented for applications of all plated beam. Finally, numerical results obtained with this method are in agreement of the existing solutions and the experimental results.

BR2K: A Replication and Recovery Technique Using Kubernetes for Blockchain Services

  • Kwon, Min-Ho;Lee, Myung-Joon
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.10
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    • pp.77-86
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    • 2020
  • In this paper, we propose a technique for blockchain service replication and recovery using kubernetes(BR2K) that robustly executes blockchain services based on replication and supports systematic recovery in case of the service failure. Blockchain services are being developed and applied in various fields such as administration, finance, and medical systems based on the features of blockchain, such as decentralization, high security, and data integrity. In such areas where service continuity is important, it is necessary to provide robustness for execution of blockchain services, and a recovery plan for service failure is also required. To this end, BR2K provides an execution replication technique that systematically supports the sustainable execution of blockchain application services. Also, it introduces a robust container registry based on the blockchain service registry, systematically supporting the recovery of service failures by using it. In addition, Truffle, a blockchain service development framework, is extended to utilize the Kubernetes container management tool, and BR2K provides a technique for rapidly deploying blockchain services using the extended framwork.

Numerical Verification for Plane Failure of Rock Slopes Using Implicit Joint-Continuum Model (내재적 절리-연속체 모델을 이용한 암반사면 평면파괴의 수치해석적 검증)

  • Shin, Hosung
    • Journal of the Korean Geotechnical Society
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    • v.36 no.12
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    • pp.125-132
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    • 2020
  • Embedded joints in the rock mass are a major constituent influencing its mechanical behavior. Numerical analysis requires a rigorous modeling methodology for the rock mass with detailed information regarding joint properties, orientation, spacing, and persistence. This paper provides a mechanical model for a jointed rock mass based on the implicit joint-continuum approach. Stiffness tensors for rock mass are evaluated for an assemblage of intact rock separated by sets of joint planes. It is a linear summation of compliance of each joint sets and intact rock in the serial stiffness system. In the application example, kinematic analysis for a planar failure of rock slope is comparable with empirical daylight envelope and its lateral limits. Since the developed implicit joint-continuity model is formulated on a continuum basis, it will be a major tool for the numerical simulations adopting published plenteous thermal-hydro-chemical experimental results.

MPS eutectic reaction model development for severe accident phenomenon simulation

  • Zhu, Yingzi;Xiong, Jinbiao;Yang, Yanhua
    • Nuclear Engineering and Technology
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    • v.53 no.3
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    • pp.833-841
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    • 2021
  • During the postulated severe accident of nuclear reactor, eutectic reaction leads to low-temperature melting of fuel cladding and early failure of core structure. In order to model eutectic melting with the moving particle semi-implicit (MPS) method, the eutectic reaction model is developed to simulate the eutectic reaction phenomenon. The coupling of mass diffusion and phase diagram is applied to calculate the eutectic reaction with the uniform temperature. A heat transfer formula is proposed based on the phase diagram to handle the heat release or absorption during the process of eutectic reaction, and it can combine with mass diffusion and phase diagram to describe the eutectic reaction with temperature variation. The heat transfer formula is verified by the one-dimensional melting simulations and the predicted interface position agrees well with the theoretical solution. In order to verify the eutectic reaction models, the eutectic reaction of uranium and iron in two semi-infinite domains is simulated, and the profile of solid thickness decrease over time follows the parabolic law. The modified MPS method is applied to calculate Transient Reactor Test Facility (TREAT) experiment, the penetration rate in the simulations are agreeable with the experiment results. In addition, a hypothetical case based on the TREAT experiment is also conducted to validate the eutectic reaction with temperature variation, the results present continuity with the simulations of TREAT experiment. Thus the improved method is proved to be capable of simulating the eutectic reaction in the severe accident.

Truncus Arteriosus -Report of a Case- (동맥간(動脈幹) 1례(例) 보고(報告))

  • Hong, Jang Soo;Park, Joo Chul;Rho, Joon Ryang;Kim, Chong Whan;Suh, Kyung Phil;Lee, Yung-Kyoon
    • Journal of Chest Surgery
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    • v.9 no.2
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    • pp.271-275
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    • 1976
  • Truncus arteriosus is a rare and highly lethal cardiac anomaly characterized by a single arterial trunk emerging from the heart and supplying the coronary, systemic, and pulmonary circulations, The first successful correction of truncus arteriosus was reported by McGoon et al. in 1968 and was based on experimental work reported by Rastelli et al. in 1967 in which a conduit consisting of a homograft of the ascending aorta and aortic valve was used to establish continuity between the right ventricle and the pulmonary arteries, Modification of this procedure using a Dacron tube valved with porcine xenograft instead of a homograft have resulted in the current definite treatment for truncus arteriosus. This report describes an 3 years and 4 months old boy with heart failure from type I truncus arteriosus who was diagnosed as the V. S. D. with pulmonary hypertension preoperatively and underwent corrective surgery employing the Rastelli procedure using a Dacron conduit valved with canine xenograft, but died due to massive bleeding from the anastomosis sites in operating room.

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Three-dimensional simplified slope stability analysis by hybrid-type penalty method

  • Yamaguchi, Kiyomichi;Takeuchi, Norio;Hamasaki, Eisaku
    • Geomechanics and Engineering
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    • v.15 no.4
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    • pp.947-955
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    • 2018
  • In this study, we propose a three-dimensional simplified slope stability analysis using a hybrid-type penalty method (HPM). In this method, a solid element obtained by the HPM is applied to a column that divides the slope into a lattice. Therefore, it can obtain a safety factor in the same way as simplified methods on the slip surface. Furthermore, it can obtain results (displacement and strain) that cannot be obtained by conventional limit equilibrium methods such as the Hovland method. The continuity condition of displacement between adjacent columns and between elements for each depth is considered to incorporate a penalty function and the relative displacement. For a slip surface between the bottom surface and the boundary condition to express the slip of slope, we introduce a penalty function based on the Mohr-Coulomb failure criterion. To compute the state of the slip surface, an r-min method is used in the load incremental method. Using the result of the simple three-dimensional slope stability analysis, we obtain a safety factor that is the same as the conventional method. Furthermore, the movement of the slope was calculated quantitatively and qualitatively because the displacement and strain of each element are obtained.

A Study of Basic Design Method for High Availability Clustering Framework under Distributed Computing Environment (분산컴퓨팅 환경에서의 고가용성 클러스터링 프레임워크 기본설계 연구)

  • Kim, Jeom Goo;Noh, SiChoon
    • Convergence Security Journal
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    • v.13 no.3
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    • pp.17-23
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    • 2013
  • Clustering is required to configure clustering interdependent structural technology. Clustering handles variable workloads or impede continuity of service to continue operating in the event of a failure. Long as high-availability clustering feature focuses on server operating systems. Active-standby state of two systems when the active server fails, all services are running on the standby server, it takes the service. This function switching or switchover is called failover. Long as high-availability clustering feature focuses on server operating systems. The cluster node that is running on multiple systems and services have to duplicate each other so you can keep track of. In the event of a node failure within a few seconds the second node, the node shall perform the duties broken. Structure for high-availability clustering efficiency should be measured. System performance of infrastructure systems performance, latency, response time, CPU load factor(CPU utilization), CPU processes on the system (system process) channels are represented.

ON CONSISTENCY OF SOME NONPARAMETRIC BAYES ESTIMATORS WITH RESPECT TO A BETA PROCESS BASED ON INCOMPLETE DATA

  • Hong, Jee-Chang;Jung, In-Ha
    • The Pure and Applied Mathematics
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    • v.5 no.2
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    • pp.123-132
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    • 1998
  • Let F and G denote the distribution functions of the failure times and the censoring variables in a random censorship model. Susarla and Van Ryzin(1978) verified consistency of $F_{\alpha}$, he NPBE of F with respect to the Dirichlet process prior D($\alpha$), in which they assumed F and G are continuous. Assuming that A, the cumulative hazard function, is distributed according to a beta process with parameters c, $\alpha$, Hjort(1990) obtained the Bayes estimator $A_{c,\alpha}$ of A under a squared error loss function. By the theory of product-integral developed by Gill and Johansen(1990), the Bayes estimator $F_{c,\alpha}$ is recovered from $A_{c,\alpha}$. Continuity assumption on F and G is removed in our proof of the consistency of $A_{c,\alpha}$ and $F_{c,\alpha}$. Our result extends Susarla and Van Ryzin(1978) since a particular transform of a beta process is a Dirichlet process and the class of beta processes forms a much larger class than the class of Dirichlet processes.

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Experimental testing and evaluation of coating on cables in container fire test facility

  • Aurtherson, P. Babu;Hemanandh, J.;Devarajan, Yuvarajan;Mishra, Ruby;Abraham, Biju Cherian
    • Nuclear Engineering and Technology
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    • v.54 no.5
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    • pp.1652-1656
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    • 2022
  • Fire tests were conducted on cables using fire-retardant paint employed in nuclear power plants that transmit electrical power, control and instrument signals. The failure criteria of various power and control cables coated with fire retardant coating at three different coating thicknesses (~0.5 mm, 1.0 mm & 1.5 mm) were studied under direct flame test using Container Fire Test Facility (CFTF) based on standard tests for bare cables. A direct flame fire test was conducted for 10 min with an LPG ribbon burner rated at ten by fixing the cable samples in a vertical cable track. Inner sheath temperature was measured until ambient conditions were achieved by natural convection. The cables are visually evaluated for damage and the mass loss percentage. Cable functionality is ascertained by checking for electrical continuity for each sample. The thickness of cable coating on fire exposure is also studied by comparing the transient variation of inner sheath temperature along the Cable length. This study also evaluated the adequacy of fire-retardant coating on cables used for safety-critical equipment in nuclear power plants.

Investigation of a new steel-concrete connection for composite bridges

  • Papastergiou, Dimitrios;Lebet, Jean-Paul
    • Steel and Composite Structures
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    • v.17 no.5
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    • pp.573-599
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    • 2014
  • A new type of connection for steel-concrete composite bridges was developed by the Steel Structures Laboratory of Ecole Poytechinque $F{\acute{e}}d{\acute{e}}rale$ de Lausanne. Resistance to longitudinal shear is based on the development of shear stresses in the confined interfaces which form the connection. Confinement is provided by the reinforced concrete slab which encloses the connection and restrains the uplift (lateral separation) of the interfaces by developing normal stresses. The experimental investigation of the interfaces, under static and cyclic loading, enabled the development of the laws describing the structural behaviour of each interface. Those laws were presented by the authors in previous papers. The current paper focuses on the continuity of the research. It presents the experimental investigation on the new connection by means of push-out tests on specimens submitted to static and cyclic shear loading. Investigation revealed that the damage in the connection, due to cyclic loading, is expressed by the accumulation of a residual slip. A safe fatigue failure criterion is proposed for the connection which enabled the verification of the connection for the fatigue limit state with respect to the limit of fatigue. A numerical model is developed which takes into account the laws describing the interface behaviour and the analytical expressions for the confinement effect, the latter obtained by performing finite element analysis. This numerical model predicts the shear resistance of the connection and enables to assess its fatigue limit which is necessary for the fatigue design proposed.