• Computers and Concrete
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• v.21 no.5
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• pp.547-557
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• 2018

This paper measures the mechanical response of precast pavement joints under moving axle loads using the finite-element method, and the models were validated with results of field tests. In order to increase the ability to use the non-linear FE analysis for design and assessment of precast pavement subjected to moving axle load, this paper investigated the effects of different load transfer between the slabs using the ABAQUS finite-element package to solve the nonlinear explicit model equations. The assembly of the panels using dowels and groove-tongue keys has been studied to assess the efficiency of keyway joint system. Concrete damage plasticity model was used to calculate the effects of permanent damages related to the failure mechanisms. With aggregate interlock as the only load transferring system, Load transfer efficiency (LTE) is not acceptable when the axle load reaches to slab joints. The Finite-element modelling (FEM) results showed that keyway joints significantly reduced tensile stresses developed at the mid-slab. Increasing the thickness of the tongue the LTE was improved but with increasing the height of the tongue the LTE was decreased. Stresses are transferred to the adjacent slab efficiently when dowels are embedded within the model. When the axle load approaches joints, tensile damage occurs sooner than compressive damage, but the damage rate remains constant, then compressive damage increases significantly and become the major form of distress under the dowels.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.187-190
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• 2001

Response surface method is applied to evaluate the reliability of laminated composite panels. Since the linear and nonlinear first-ply failure load are computed using deterministic finite element analysis, new probabilistic finite element analysis is not necessary. Tsai-Wu criterion is used to construct the limit state suface. Material properties, layer thickness and lamina strengths of laminated composite panel are treated as random design variables. feasibility and accuracy of current method is validated using Monte-Carlo method Which perform thousand times of finite element analysis directly.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.2
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• pp.271-277
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• 1994

The fatigue crack opening behavior is analyzed using finite element method. Because extremely fine mesh subdivision is required when using constant stress constant strain triangular element, this study uses conventional two dimensional eight node isoparametric elements. Since plasitc zone size is similar to crack propagating length per each load cycle because of relatively large element size, a new analysis model that a crack propagates every two load cycle is suggested. the opening load and crack opening displacement can be obtained accurately by this method.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2054-2057
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• 2005

In this paper, the application of finite element method to design the shape of load cell as an illustrative case study is described. The relationship between the various shapes of load cell and their stress characteristic were analyzed by COSMOS simulation program. The results obtained from the proposed analysis can be applied to determine the appropriate position of strain gauges for good quality load cell. The experimental results show the good efficiency of the proposed technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.528-533
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• 1995

An analyical method is proposed to construct a clamp jointed structure as an equivalent stiffness matrix element in the finite element modal analysis of a complex beam structure. Static structural analysis was first made for the detail finite element model of the clamp joint. Utilizing the results of this analysis, the equivalent stiffness matrix element was buildup by using the flexibility influence coefficient method and Guyan condensation. The proposed method was applied to finite element modal analysis of a clamp jointed cantilever beam. And the finite element analysis results were compared to those experimental modal analysis. Comparison shows doog agreement each other Furthermore the effects of normal contact(or clamping) load on the equivalent stiffness matrix was also examined. The equivalent stiffness matrix showed little change in spite of the remakable increase in the contact load on the clamp joint.

• Steel and Composite Structures
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• v.23 no.1
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• pp.131-142
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• 2017

Determining limit load for a pressure bearing structure using elastic-plastic finite element analysis was computationally very expensive. A series of robust methods using elastic modulus adjustment techniques (EMAP) to identify the limit load directly were proposed. The numerical implementation of the robust method had the potential to be an attractive alternative to elastic-plastic finite element analysis since it was simple, and required less computational effort and computer storage space. Another attractive feature was that the method provided a go/no go criterion for the limit load, whereas the results of an elastic-plastic analysis were often difficult to interpret near the limit load since it came from human sources. To explore the performance of the method further, it was applied to a number of configurations that include two-dimensional and three-dimensional effects. In this study, limit load of cylinder with nozzle was determined by the robust methods.

• Smart Structures and Systems
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• v.32 no.6
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• pp.371-382
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• 2023

Box girder bridges are now widely used in bridge construction, and it is necessary to perform load rating regularly to evaluate the load capacity of box girder bridges. Load testing is a common measure for load rating. However, the bridge must be loaded by many trucks under different loading conditions, which is time-consuming and laborious. To solve this problem, this paper proposes a load rating method for box girder bridges based on rapid moving loads testing. The method includes three steps. First, the quasi-influence factors of the bridge are obtained by crossing the bridge with rapidly moving loads, and the structural modal parameters are simultaneously obtained from the dynamic data to supplement. Second, an objective function is constructed, consisting of the quasi-influence factors at several measurement points and structural modal parameters. The finite element model for load rating is then updated based on the Rosenbrock method. Third, on this basis, a load rating method is proposed using the updated model. The load rating method proposed in this paper can considerably reduce the time duration of traditional static load testing and effectively utilize the dynamic and static properties of box girder bridges to obtain an accurate finite element model. The load capacity obtained based on the updated model can avoid the inconsistency of the evaluation results for the different structural members using the adjustment factors specified in codes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4C
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• pp.159-167
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• 2012

In this study, laboratory model pile-load test and finite element analysis were carried out to compare and analyze the strain behaviour around the model pile tip. In order to simulate the pile load, both the LCM(load control method)and DCM(displacement control method) were introduced to determine which one is appropriate for the FE simulation. In contrast to the previous simulation method, two interface elements around the model pile were used to consider the slip effect in the finite element analysis and its results were compared to the model test. Through this study it was found that the degree of non-associated flow was a dominant factor in terms of numerical solution convergence. In addition, an improved FE mesh was required to obtain the symmetric distribution of the maximum shear strain contour.

• Journal of the Korea Concrete Institute
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• v.11 no.5
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• pp.33-40
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• 1999

An improved finite element modeling technique is proposed for the assessment of load carrying capacity of partially prestressed concrete girder bridges. Based on the finite element method of analysis, shell and frame elements are used to model the slab and girders of the superstructure, respectively. In the modeling of superstructure, the emphasis is placed on the use of rigid link between the middle surface of slab an mid-plane of girder. This paper also includes the comparision of three different equations that are used in the calculation of effective moment of inertia for the partially prestressed concrete girders. Numerical analysis is performed for the unstrengthened and strengthened bridges. The obtained results are compared with those of load test for a prototype bridge. A good agreement is achieved between the numerical solutions by using the proposed method load test results.

• Structural Engineering and Mechanics
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• v.43 no.4
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• pp.439-448
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• 2012

This paper investigates the load sharing of double circular arc helical gears considering the influence of assembly errors. Based on a load sharing formulae, a three-dimensional finite element tooth contact analysis (TCA) is implemented with commercial software package ANSYS. The finite element grid for the double circular arc gear contact model is automatically generated by using the APDL (ANSYS Parameter Design Language) embedded in ANSYS. The realistic rotation of gears is achieved by using a coupling degree-of-freedom method. Numerical simulations are carried out to exemplify the proposed approach. The distribution of contact stress and bending stress under specific loading conditions are computed and compared with those obtained from Hertz contact theory and empirical formulae to demonstrate the efficiency of the proposed load sharing calculation formulae and TCA approach.