• Nuclear Engineering and Technology
• /
• v.54 no.4
• /
• pp.1382-1393
• /
• 2022

This paper investigates the seismic behavior of an electrical cabinet considering the influence of equipment-anchor-interaction (EAI) that is generally not taken into consideration in a decoupled analysis. The hysteresis behavior of an anchor bolt in concrete was thereby considered to highlight this interaction effect. To this end, the experimental behavior of an anchor bolt under reversed cyclic loading was taken from the recently developed literature, and a numerical model for the anchor hysteresis was developed using the component approach. The hysteresis properties were then used to calibrate the multi-linear link element that is implemented as a boundary condition for the cabinet incorporating the EAI. To highlight this EAI further, the nonlinear time history analysis was performed for a cabinet considering the hysteresis behavior comparative to a fixed boundary condition. Additionally, the influence on the seismic fragility was evaluated for the operational and structural condition of the cabinet. The numerical analysis considering the anchor hysteresis manifests that the in-cabinet response spectra (ICRS) are significantly amplified with the corresponding reduction in the seismic capacity of 25% and 15% for an operational and structural safety condition under the selected protocols. Considering the fixed boundary condition over a realistic hysteresis behavior of the anchor bolt is more likely to overestimate the seismic capacity of the cabinet in a seismic qualification procedure.

• Structural Engineering and Mechanics
• /
• v.72 no.6
• /
• pp.713-722
• /
• 2019

Micromechanics is a technique for the analysis of composites or heterogeneous materials which focuses on the components of the intended structure. Each one of the components can exhibit isotropic behavior, but the microstructure characteristics of the heterogeneous material result in the anisotropic behavior of the structure. In this research, the general mechanical properties of a 3D anisotropic and heterogeneous Representative Volume Element (RVE), have been determined by applying periodic boundary conditions (PBCs), using the Asymptotic Homogenization Theory (AHT) and strain energy. In order to use the homogenization theory and apply the periodic boundary conditions, the ABAQUS scripting interface (ASI) has been used along with the Python programming language. The results have been compared with those of the Homogeneous Boundary Conditions method, which leads to an overestimation of the effective mechanical properties. According to the results, applying homogenous boundary conditions results in a 33% and 13% increase in the shear moduli G₂₃ and G₁₂, respectively. In polymeric composites, the fibers have linear and brittle behavior, while the resin exhibits a non-linear behavior. Therefore, the nonlinear effects of resin on the mechanical properties of the composite material is studied using a user-defined subroutine in Fortran (USDFLD). The non-linear shear stress-strain behavior of unidirectional composite laminates has been obtained. Results indicate that at arbitrary constant stress as 80 MPa in-plane shear modulus, G₁₂, experienced a 47%, 41% and 31% reduction at the fiber volume fraction of 30%, 50% and 70%, compared to the linear assumption. The results of this study are in good agreement with the analytical and experimental results available in the literature.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.911-912
• /
• 2010

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.61 no.4
• /
• pp.622-628
• /
• 2012

This paper proposes an environment monitoring algorithm using a behavior-based multiple robot system. This paper handles an escort and a boundary-tracking especially. Unlike previous research works, the proposed environment monitoring system which is based on the behavior-based multiple robot control allows the system to employ the reusable code and general algorithm. Also, the proposed method can be applied to cheaper process with low performances. In the proposed method, escort and boundary-tracking missions are constructed by weighted sum of predefined basic behaviors after redefining the basic behaviors in previous works and introducing the novel basic behavior. Simulation results of the proposed method are included to demonstrate the practical application of the proposed algorithm.

• Computational Structural Engineering
• /
• v.9 no.4
• /
• pp.127-134
• /
• 1996

This paper is about a progressive fracture analysis of concrete by boundary element method. From both displacement boundary integral equation and traction boundary integral equation of solids with cracks, a boundary integral equation for crack problem is derived. For the analysis of progressive fracture of concrete, fracture process zone is modelled based on Dugdale-Barenblatt model with linear tension-softening curve. By using the boundary element modeling, the progressive fractures of concrete beam and compact-tension specimens with various loading conditions are analyzed and compared with experiments. The analysis results show that the technique in this paper can predict the maximum strength and the nonlinear behavior of concrete including post-peak behavior.

• Korean Journal of Mathematics
• /
• v.14 no.1
• /
• pp.65-70
• /
• 2006

In this article, we mention some subsequent developments of the theory of cluster sets, and present a new boundary cluster set for a simply connected domain in the complex plane and its applications.

• Honam Mathematical Journal
• /
• v.19 no.1
• /
• pp.81-86
• /
• 1997

The aim of this paper is to prove the boundary behavior between the Caratheodory and Kobayashi-Royden metrics in a strongly pseudoconvex bounded domain with $C^2$-boundary in $\mathbb{C}^n$ and to show that the converse does not holds. S. Venturini([Ven]) proved the corresponding result with distances in place of the infinitesimal metrics.

• Bulletin of the Korean Chemical Society
• /
• v.7 no.4
• /
• pp.271-275
• /
• 1986

The Smoluchowski equation with a step potential is solved in one-dimensional case and three-dimensional case with spherical symmetry. Exact analytic expressions for the solution and the remaining probability are obtained in one-dimensional case for the reflecting boundary condition and the long time behavior of the remaining probability is compared with the earlier work. In three-dimensional case, only the long time behavior is evaluated. More general case with the radiation boundary condition is also investigated and the results are shown to approach correct limits of the reflecting boundary condition.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2002.05a
• /
• pp.97-100
• /
• 2002

In this research, the impact behavior of the boundary between MMC-reinforced SiC whisker and Al alloy were studied. It is known that the resultant of the interfacial reaction between SiC whisker and Al alloy has brittle and low toughness property. In this paper, impact behavior of graded MMC & Al alloy shows the interfacial opening at the boundary. Generally this phenomenon is generated by thermal residual stress, brittle interfacial reaction resultant and difference of the deflection. So, these results may be interpreted as a macroscopic method of measuring the interfacial strength between matrix and reinforcement

• East Asian mathematical journal
• /
• v.22 no.1
• /
• pp.53-59
• /
• 2006

We introduce the resistant length and examine its properties. And consider the applications of resistant length to the boundary behavior of conformal mappings. We obtain the theorems in the connection with the resistant length zero and the fundamental sequences. The method of resistant length leads a simple proofs of theorems.