• Journal of the Korea institute for structural maintenance and inspection
• /
• v.5 no.3
• /
• pp.213-223
• /
• 2001

This paper presents an analytical procedure for the time-dependent analysis of the multi-story prestressed concrete structure under the construction stage. To account for the actual structural behavior, the procedure considers the effects due to the construction interval and the time-dependent losses of prestress at every construction step on the entire structural response. A numerical study is performed to demonstrate the general validity of the approach and to quantitatively evaluate the effects resulted from the time-dependent behaviors during construction. Recommendations and conclusions are developed by comparisons with structural responses using the present and conventional methods of analysis. The comparative results show that both effects of sequential construction and time-dependent prestress losses should be considered for the construction stage analysis.

• Earthquakes and Structures
• /
• v.14 no.3
• /
• pp.229-239
• /
• 2018

Under strong ground motion, pounding can be caused because of the different dynamic properties between two adjacent buildings. Using different structural systems in two adjacent structures makes a difference in the lateral stiffness and thus changes the pounding force between them. In this paper, the effect of the structural system of adjacent buildings on the amount of force applied by pounding effects has been investigated. Moment resisting frame systems (MRFs), lateral X-bracing system (LBS), shear wall system (SWS) and dual system (DS) have been investigated. Four different cases has been modelled using finite element (FE) method. The number of stories of the two adjacent buildings is different in each case: case 1 with 6 and 4 stories, case 2 with 9 and 6 stories, case 3 with 15 and 6 stories and case 4 with 10 and 10 stories. The structures have been modelled three-dimensionally. Non-linear time history analysis has been done on the structures using the finite element software SAP2000. In order to model pounding effects, the non-linear gap elements have been used.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.10a
• /
• pp.217-220
• /
• 2003

Due to the lighter weight and the higher freedom of design than metals plastics have been spot lighted in a wide number of applications. In the making plastic parts injection-molding process is one of the most general methods. During the injection molding process, filling-packing-cooling process, plastics have exposed to several external stresses and then plastic parts injected have molding effects which are known as anisotropic properties, orientation, and residual stress. Those molding effects are often shown as unexpected phenomena which are warpage, strength decrease, stiffness reduction, etc. In case of glass fiber filed plastics these effects are more significant than the ufilled ones. Therefore the molding effects have to be considered in the parts design using glass fiber reinforced plastics. We have developed the interface program in order to consider the molding effects in structural analyses of plastic parts using Heirarchical structural searching and layer handling in direction of thickness algorithm. The advantages of this program are the freedom of FE mesh between molding and structural analysis, the variable layer to the thickness direction of parts and the conveniences of data transferring and checking

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.2 no.3
• /
• pp.212-222
• /
• 1998

In several structural problems, the low concrete strength of compression members has the severest influence on the structural safety. However, the repairing and strengthening techniques for compression members are not established and evaluated. This study aimed to develop and evaluate the rehabilitation techniques to obtain proper structural strength of wall with low concrete strength. The specimens with low strength of concrete were retrofitted with commonly using section increase method and epoxy bonded glass fiber techniques. The tests were executed to failure under concentric and eccentric loads. In this paper, the structural behavior and failure modes were investigated to evaluate the strengthening effects of walls subjected to compression and out-of-plane bending.

• Ocean Systems Engineering
• /
• v.4 no.3
• /
• pp.169-183
• /
• 2014

For the reliable design of substructure supporting offshore wind turbines it is very important to reduce the effects of wave forces. Since the substructure is strongly influenced by the effects of wave forces as the size of substructure increases. In the present study, the hybrid substructure with multi-cylinder is newly suggested to reduce the effects of wave forces. Using diffraction theory the scattering waves in a fluid region are expressed by an Eigenfunction expansion method with three dimensional potential theory to calculate the wave force acting on the hybrid substructure. The wave force and wave run-up acting on the hybrid substructure is presented to examine the water wave interaction according to the variation of cylindrical size and the distance among cylinders. It is found that the suggested hybrid substructure with multi-cylinder is very useful to reduce the effects of wave forces acting on the substructure for offshore wind turbines.

• Journal of Families and Better Life
• /
• v.33 no.4
• /
• pp.33-50
• /
• 2015

The purpose of this study was examining the effects of family sandplay therapy with structural family therapy in improving the family strengths of children with emotional and behavioral disorders. First, we looked for a way to combine family sandplay therapy with structural family therapy and formulated an approach that could maximize the strengths of each theory and complement each other's weaknesses. And then we applied family sandplay therapy together with structural family therapy and analyzed its effects on family strengths. The subjects of this study were 10 families of children with emotional and behavioral disorders, and they were divided into an experimental group with 5 families and a control group with the other 5. To the experimental group received 16 sessions of family sandplay therapy with structural family therapy. In order to prove the effectiveness of family sandplay therapy with structural family therapy on family strengths, a family relationship( husband-wife relationship, parent-child relationship, and sibling relationship) scale and a family function(family cohesion, family adaptability) scale were used. The main findings of this study are as follows. First, the family relationships of the families with emotional-behavioral disorder children were improved after the application of family sandplay therapy with structural family therapy. Second, the application of family sandplay therapy with structural family therapy improved the family function of families with emotional-behavioral disorder children. Third, in the course of family sandplay therapy with structural family therapy, family sand tray was changed in a pro-healing direction, and family structure was also transformed from a dysfunctional structure to a functional one. As previously stated, family sandplay therapy with structural family therapy for families of children with emotional and behavioral disorders enhanced family strengths through improving family relationships and restoring family functions.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.1 no.2
• /
• pp.141-149
• /
• 1997

The major objects of this study is to investigate experimentally the strengthening effects and post-failure behavior of reinforced concrete beam-columns with enlarged sections. Tests are carried out to evaluate the influences of axial load intensities, thickness of encased steel plates and reinforcing bars in the grouted parts on the structural behavior of the specimens. The test results show that the amount of reinforcing bars and thickness of steel plate significantly affect on the structural behavior. The ultimate moment capacities of reinforced concrete beam-columns encased with 2mm-thick steel plate are significantly increased to about 10 times of those of unstrengthened specimens.

• Structural Engineering and Mechanics
• /
• v.21 no.5
• /
• pp.507-518
• /
• 2005

In the shear-lag analysis of structures deterministic procedure is insufficient to provide complete information. Probabilistic analysis is a holistic approach for analyzing shear-lag effects considering uncertainties in structural parameters. This paper proposes an efficient and accurate algorithm to analyze shear-lag effects of structures with parameter uncertainties. The proposed algorithm integrated the advantages of the response surface method (RSM), finite element method (FEM) and Monte Carlo simulation (MCS). Uncertainties in the structural parameters can be taken into account in this algorithm. The algorithm is verified using independently generated finite element data. The proposed algorithm is then used to analyze the shear-lag effects of a simply supported beam with parameter uncertainties. The results show that the proposed algorithm based on the central composite design is the most promising one in view of its accuracy and efficiency. Finally, a parametric study was conducted to investigate the effect of each of the random variables on the statistical moment of structural stress response.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2001.10a
• /
• pp.143-150
• /
• 2001

In this paper, the effects of vehicle loads on flat slab system are investigated based on the previous studies on beam-girder parking structural system. The influence surfaces of flat slab for typical design section are determined for the purpose of obtaining member forces under vehicle loads. In addition, the equivalent vehicle load factors for flat slab parking structures are suggested using neural network. It has been found that vehicle load effects of flat slab system are dominant for the center positive moment in both column and middle strip, as like beam-girder parking structural system.

• Computational Structural Engineering
• /
• v.25 no.1
• /
• pp.17-20
• /
• 2012