• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.404-411
• /
• 2002

The PSC 2-span-continuous-bridge by Up-Down Method on construction process is used for this research. It is measured the strain of lower-steel-plate at continuous section on the active range of negative moment at the stage of introducing compressive stress to bottom-plate and compared with results of structural analysis. On the basis of these results, it is confirmed the introduced compressive stress tか bottom-plate. The object of this research is presenting the degree of continuity at the stage of lifting up process.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1997.10a
• /
• pp.80-86
• /
• 1997

Recently, the box-girder bridge became quite popular because of the effectiveness of the box section against torsional deformation, and the finite element method has been one of the powerful and versatile method for obtaining the solution of box-girder bridge. The finite element method is used to solve a box girder which is built up with flat plates such as flanges, webs and diaphragm, and box girder is idealized by 8-nodes 2-dimensional isoparmetric finite element. To investigate the stress of diaphragm, substructure analysis is performed with two Parameters which are the location of support and slope of web.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1995.04a
• /
• pp.28-34
• /
• 1995

Behavior of underground structural systems is usually complicated because of various unknown parameters. In order to construct those structural systems safely and economically, exact identification of the system parameters and accurate analysis of the system behaviors are essentially required. In this study, a forward analysis program, which is able to eliminate numerical errors due to far field boundary effect, is developed by coupling finite and boundary elements. In this coupled analysis, boundary elements are used in the semi-infinite domain where stress variation is small, and finite elements in the stress concentration region where material nonlinearity should be considered. Then, a back analysis program which can identify the system parameters is developed using the direct method to be combined with the forward analysis program. The elastic modulus and initial stress, which are most important in the description of the behavior of underground structures, are taken as the system parameters. A simple example is examined 0 show that the method can be used effectively.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1991.04a
• /
• pp.79-83
• /
• 1991

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 1999.04a
• /
• pp.287-294
• /
• 1999

The tensegrity structure by prestressed cable, which may have large freedom in scale and form and therefore are received much attention from the view points of their light weight and aesthetics, is a very flexible and geometrically unstable structure because the cable material has little initial rigidity. For the stable self-equilibrated state of the usually very deformable structure, the method to find the optimal initial stress by the shape analysis is proposed in this paper. The proposed procedure is to derive the nonlinear finite element formula of cable and truss members considering geometric nonlinearity and used to modified load incremental method adding to Newton-Raphson method with the proposed condition for optimal initial stress. The result of the shape analysis for the tensegrity structure with the radius of 30m is shown the almost approximated shape to architectural shape and the changed procedure of initial stress

• Computational Structural Engineering
• /
• v.9 no.1
• /
• pp.85-91
• /
• 1996

The focus of the present work is on the computation of the stress intensity factor for the crack at the elastic-viscoelastic bimaterial interface. First, the stress intensity factor for an interface crack in dissimilar elastic and viscoelastic materials is dervied by applying the correspondence principle to associated elastic expression. Then the time-domain boundary element analysis is performed to calculate the stress intensity factor. Numerical results show that the proposed method is very useful for the analysis of the interface crack in elastic and viscoelastic materials.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2002.10a
• /
• pp.354-361
• /
• 2002

This paper propose section properties factor to generate stress history for fatigue analysis and safety inspection of steel bridge. A methodology is described for the computation of numerical stress histories in the steel truss bridge, caused by the vehicles using section properties factor. The global 3-D beam model of bridge is combined with the local shell model of selected details. Joint geometry is introduced by the local shell model. The global beam model takes the effects of joint rigidity and interaction of structural elements into account. Connection nodes in the global beam model correspond to the end cross-section centroids of the local shell model. Their displacements are interpreted as imposed deformations on the local shell model. The load cases fur the global model simulate the vertical unit force along the stringers. The load cases fer the local model are imposed unit deformations. Combining these, and applying vehicle loads, numerical stress histories are obtained. The method is illustrated by test load results of an existing bridge.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.14 no.3
• /
• pp.309-315
• /
• 2001

The Stress intensity factors for edge cracks located at the bonding interface between the elastic semiconductor chip and the viscoelastic adhesive layer have been investigated. Such cracks might be generated due to stress singularity in the vicinity of the free surface. The domain boundary element method(BEM) has been employed to investigate the behavior of interface stresses. The overall stress intensity factor for the case of a small interfacial edge crack has been computed. The magnitude of stress intensity factors decrease with time due to viscoelastic relaxation.

• Computational Structural Engineering
• /
• v.9 no.3
• /
• pp.115-123
• /
• 1996

A finite element analysis of a trunnion pipe anchor is presented. The structure is analyzed for the case of internal pressure and moment loadings. The stress results are categorized into the average (membrance) and the linearly varying(bending) stresses through the thickness. The resulting stresses are interpreted per Section III of the ASME Boiler and Pressure Vessel Code from which the Primary (B/sub 1/) and Secondary(C/sub 1/) stress indices for pressure, the Primary(B/sub 2R/, B/sub 2T/) and Secondary(C/sub 2R/, C/sub 2T/) stress indices for moment are developed. Several analyses were performed for various structural geometries in order to obtain empirical representation for the stress indices in terms of dimensionless ratios.

• Computational Structural Engineering
• /
• v.7 no.2
• /
• pp.121-129
• /
• 1994

The Finite Element Method(FEM), which is existing stress analysis method, requires substantial amounts of efforts for analysis of perforated plates. An equivalent solid plate analysis method is developed in this paper. A perforated plate is assumed to be an equivalent solid plate in this method. Stress analysis is performed for this equivalent solid plate using effective material properties, and then these stresses are converted to the actual stresses of the original perforated plate. A case study is conducted for a rectangularly arrayed perforated plate using the proposed method in this paper. Compared and analyzed with respect to those calculated by the existing stress analysis method, the result seems to be satisfied in terms of its practicality and more conservative with respect to margin in design application.