• Structural Engineering and Mechanics
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• v.85 no.3
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• pp.353-367
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• 2023

An extended parametric study based on nonlinear finite element analyses is performed to assess the key factors affecting the shear behaviour of exterior beam-column joints of unbraced reinforced concrete frames. Extensive results are presented, the major conclusion being that the few shear behaviour models for exterior reinforced concrete beam-column joints available in the literature do not properly account for some of the most influential factors. The present results are also compared with recently published results for interior joints, showing that while some factors have a similar influence on interior and exterior joints others are relevant for only one of these types of joints. This also confirms, numerically, that some resisting mechanisms of exterior joints differ from those of interior joints.

• Structural Engineering and Mechanics
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• v.67 no.6
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• pp.565-578
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• 2018

This research article reported the nonlinear finite solutions of the nonlinear flexural strength and stress behaviour of nano sandwich graded structural shell panel under the combined thermomechanical loading. The nanotube sandwich structural model is derived mathematically using the higher-order displacement polynomial including the full geometrical nonlinear strain-displacement equations via Green-Lagrange relations. The face sheets of the sandwich panel are assumed to be carbon nanotube-reinforced polymer composite with temperature dependent material properties. Additionally, the numerical model included different types of nanotube distribution patterns for the sandwich face sheets for the sake of variable strength. The required equilibrium equation of the graded carbon nanotube sandwich structural panel is derived by minimizing the total potential energy expression. The energy expression is further solved to obtain the deflection values (linear and nonlinear) via the direct iterative method in conjunction with finite element steps. A computer code is prepared (MATLAB environment) based on the current higher-order nonlinear model for the numerical analysis purpose. The stability of the numerical solution and the validity are verified by comparing the published deflection and stress values. Finally, the nonlinear model is utilized to explore the deflection and the stresses of the nanotube-reinforced (volume fraction and distribution patterns of carbon nanotube) sandwich structure (different core to face thickness ratios) for the variable type of structural parameter (thickness ratio, aspect ratio, geometrical configurations, constraints at the edges and curvature ratio) and unlike temperature loading.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.03a
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• pp.151-158
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• 2002

In the present design concept, the nonlinear behaviour of bridges is at lowed under large earthquake. The nonlinearity is, however, localized like pier, bearing, etc. Especially, pier columns are most important members for seismic performance. It is, however, difficult to solve the problem how the nonlinearity of columns should be modelled. In this study, the fiber element is used for modelling pier column. The element is a kind of structural elements like frame element, and it can model the distributed plasticity of plastic hinge. A 3 span continous bridge is taken for seismic analysis. First, the nonlinear static analysis the column at fixed support are performed so that the characteristics of column is analyzed. Second, Linear and nonlinear dynamic analysises using simplified model for longitudinal direction are carried out and the results are analyzed.

• Journal of KSNVE
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• v.3 no.2
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• pp.137-143
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• 1993

The conventional dynamic vibration absorber is very efficient in inhibiting the vibration of a machine. This is accomplished by "tuning" the absorber to the frequency of the harmonic disturbing force. If, however, the frequency of the disturbing force varies over a tuning frequency range in the normal operation of the system, the linear dynamic absorber may become inoperative and might aggravate matters particularly. This study is to endow the dynamic absorber with greater flexibility in suppressing vibrations throught a range of frequencies of the disturbing force. By introducing springs with nonlinear characteristics into its design, the results can be obtained. In this paper, the machine and the absorber were modelled as a nonlinear two-degree-of freedom system. And the concepts of nonlinear normal mode were adopted to obtain this purpose.s purpose.

• Transactions of The Korea Fluid Power Systems Society
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• v.8 no.3
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• pp.21-26
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• 2011

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seals in high speed pneumatic cylinders is analyzed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the squeeze type piston seal are simulated with variation of the seal radial installed interference, the operating pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the squeeze type piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.381-386
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• 2007

The present study is concerned with the application of Constant arc-length method that proposed by Crisfield in the investigation of the geometrically nonlinear behaviour of spatial structures composed by truss or beam element. The arc-length method can trace the full nonlinear equilibrium path of Spatial structure far beyond the critical point such as limit or bifurcation point. So, we have developed the constant arc-length method of Crisfield to analysis spatial structure. The finite element formulation is used to develop the 3d truss/beam element including the geometrical nonlinear effect. In an effort to evaluate the merits of the methods, extensive numerical studies were carried out on a number of selected structural systems. The advantages of Constant arc length method in tracing the post-buckling behavior of spatial structures, are demonstrated.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.99-104
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• 2010

Nonlinear seal friction in pneumatic cylinders can impede the performance of pneumatic systems designed for high precision positioning with favorable high speed actuation. The behaviour of an elastomeric piston seal in high speed pneumatic cylinders is analysed by nonlinear finite element analysis using ABAQUS. The contact pressures, stress and strain distributions and frictional forces of the piston seal are simulated with variation of interference fits, supply pressures, friction coefficients and piston rod velocities. The nonlinear finite element model of the piston seal is used to predict deformation of a seal, friction force and contact pressure distributions.

• Advances in materials Research
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• v.6 no.4
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• pp.349-361
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• 2017

The nonlinear thermal buckling load parameter of the laminated composite panel structure is investigated numerically using the higher-order theory including the stretching effect through the thickness and presented in this research article. The large geometrical distortion of the curved panel structure due to the elevated thermal loading is modeled via Green-Lagrange strain field including all of the higher-order terms to achieve the required generality. The desired solutions are obtained numerically using the finite element steps in conjunction with the direct iterative method. The concurrence of the present nonlinear panel model has been established via adequate comparison study with available published data. Finally, the effect of different influential parameters which affect the nonlinear buckling strength of laminated composite structure are examined through numerous numerical examples and discussed in details.

• Computers and Concrete
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• v.13 no.5
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• pp.679-694
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• 2014

The selected carrier systems of reinforced concrete frame buildings are quite important on structural damages. In this study are examined comparatively nonlinear behaviours of reinforced concrete frames which having different stiffening members under a horizontal load. In that respect, the study consists of six parametric models. With this purpose, nonlinear structural analyses of reinforced concrete frames which having different stiffening members were carried out with LUSAS which uses the finite element method. Thus, some conclusions and recommendations to mitigate the damage of reinforced concrete buildings in the future designs are aimed to present. The obtained results revealed that in terms of performance, the x-shaped diagonal elements can be used as an option to shear walls. In addition, it was found that frame-2, frame-3 and frame-4 showed a better performance than traditional frame system (frame-1).

• Steel and Composite Structures
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• v.29 no.2
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• pp.257-272
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• 2018

The research of shear connectors composed from mechanical couplers with rebar anchors, embedded in concrete, and steel bolts, as a mean of shear transfer in composite connections is presented in the paper. Specific issues related to this type of connections are local concrete pressure in the connector vicinity as well as the shear flow along the connector axis. The experimental research included 18 specimens, arranged in 5 series. Nonlinear numerical analyses using Abaqus software was conducted on corresponding FE models. Different failure modes were analysed, with emphasis on concrete edge failure and bolt shear failure. The influence of key parameters on the behaviour of shear connector was examined: (1) concrete compression strength, (2) bolt tensile strength and diameter and (3) concrete edge distance. It is concluded that bolted shear connectors with mechanical couplers have sufficient capacity to be used as shear connectors in composite structures and that their behaviour is similar to the behaviour of post installed anchors as well as other types of connectors anchored without the head.