• Steel and Composite Structures
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• v.3 no.3
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• pp.169-184
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• 2003

This paper presents a generic modelling of composite steel-concrete beams with elastic shear connection. It builds on the well-known seminal technique of Newmark, Siess and Viest, in order to formulate the partial interaction formulation for solution under a variety of end conditions, and lends itself well for modification to enable direct quantification of effects such as shrinkage, creep, and limited shear connection slip capacity. This application is possible because the governing differential equations are set up and solved in a fashion whereby inclusion of the kinematic and static end conditions merely requires a statement of the appropriate constants of integration that are generated in the solution of the linear differential equations. The method is applied in the paper for the solution of the well-studied behaviour of simply supported beams with partial interaction, as well as to provide solutions for a beam encastr$\acute{e}$ at its ends, and for a propped cantilever.

• Journal of Biomedical Engineering Research
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• v.43 no.2
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• pp.94-101
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• 2022

Recent advancement of micro/nano technology enables the development of diverse micro/nano particle-based delivery systems. Due to the multi-functionality and engineerability, particle-based delivery system are expected to be a promising method for delivery to the target cell. Since the particle-based delivery system should be delivered to the various kinds of target cell, including the cardiovascular system, cancer cell etc., it is frequently decorated with multiple kinds of targeting molecule(s) to induce specific interaction to the target cell. The surface decorated molecules interact with the cell surface expressed molecule(s) to specifically form a firm adhesion. Thus, in this study, the probability of adhesion is estimated to predict the possibility to form a firm adhesion for the multi-ligand decorated particle-based delivery system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.428-435
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• 2011

In general, thickness of the sublayers under track is designed based on concept of vertical soil reaction value or vertical stiffness. However, this design method cannot take consideration into soil-track interaction under repetitive load, traffic condition and velocity of the train. Furthermore, the reinforced roadbed soils experience complex behavior that cannot be explained by conventional stress-strain relation expressed as soil reaction value k. The reinforced roadbed soils also can produce cumulative permanent deformation under repetitive load caused by train. Therefore new design method for the sublayers under track must be developed that can consider both elastic modulus and permanent deformation. In this study, a new design concept, a rule-of-thumb, is proposed as the form of design monograph that is developed using elastic multi-layer and finite element programs by analyzing stress and deformation in the sublayers with changing the thickness and elastic modulus of the sublayers and also using data obtained from repetitive triaxial test. This new design concept can be applied to design of the reinforced roadbed before developing full version of design methodology that can consider MGT, axial load and the material properties of the layers. The new design monograph allows the user to design the thickness of the reinforced roadbed based on permanent deformation, elastic modulus and MGT.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.53-54
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• 2006

Experimental analyses on the Hydroelastic Flow-Structure Interactions on pulsed impinged jet is measured with the FSIMS(Flow-Structure Interaction Measurement System. The nozzle diameter is D=15mm and two major experiments have been carried out for the cases of the distance between the nozzle tip to the elastic wall is 6.0. The pulsed jets were controlled by a solenoid valve and were impinged onto an elastic plate (material: silicon, diameter: 350mm, thickness: 0.5mm, hardness: 15). The Reynolds numbers were 20,000 and 24,000 when the jets were impinged with the volume velocities. The results showed that the elastic plate moved slightly to the opposite direction of the jet direction at the time of valve opening. It has been shown that the vortices travelling over the surface of the wall made the elastic wall distorted locally due to a vector forces between rotating forces of the vortex and a newly-incoming flow.

• Journal of Advanced Research in Ocean Engineering
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• v.4 no.4
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• pp.146-162
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• 2018

The unsteady problem of a rigid body impact onto a floating plate is studied. Both the plate and the water are at rest before impact. The plate motion is caused by the impact force transmitted to the plate through an elastic layer with viscous damping on the top of the plate. The hydrodynamic force is calculated by using the second-order model of plate impact by Iafrati and Korobkin (2011). The present study is concerned with the deceleration experienced by a rigid body during its collision with a floating object. The problem is studied also by a fully-nonlinear computational-fluid-dynamics method. The elastic layer is treated with a moving body-fitted grid, the impacting body with an immersed boundary method, and a discrete-element method is used for the contact-force model. The presence of the elastic layer between the impacting bod- ies may lead to multiple bouncing of them, if the bodies are relatively light, before their interaction is settled and they continue to penetrate together into the water. The present study is motivated by ship slamming in icy waters, and by the effect of ice conditions on conventional free-fall lifeboats.

• Structural Engineering and Mechanics
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• v.85 no.6
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• pp.825-835
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• 2023

The effective buckling length factor is an important parameter in the elastic buckling analysis of steel structures. The present article aims at developing a new method that allows the determination of the buckling factor values for frames. The novelty of the method is that it considers the interaction between the bracing and the elastic supports for asymmetrical frames in particular. The approach consists in isolating a critical column within the frame and evaluating the rotational and translational stiffness of its restraints to obtain the critical buckling load. This can be achieved by introducing, through a dimensionless parameter 𝜙_i, the effects of coupling between the axial loading and bending stiffness of the columns, on the classical stability functions. Subsequently, comparative, and parametric studies conducted on several frames are presented for assessing the influence of geometry, loading, bracing, and support conditions of the frame columns on the value of the effective buckling length factor K. The results show that the formulas recommended by different approaches can give rather inaccurate values of K, especially in the case of asymmetric frames. The expressions used refer solely to local stiffness distributions, and not to the overall behavior of the structure.

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.267-284
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• 2012

In most of the design offices, analysis of the frame is carried out without considering the effect of the rigidity of mat. The analysis of the superstructure without modelling the foundation properly and conversely analysing the foundation system without considering the stiffness of the superstructure may mislead the estimation of the forces. This paper examines the parameters, which affect the interaction and they are grouped into relative stiffness factors ${\kappa}_{rs}$ and ${\kappa}_{sb}$. An interaction analysis is performed for the five storeyed space frame of 3 bays ${\times}$ 5 bays, using ANSYS finite element code. The soil was treated as an isotropic, homogenous and elastic half space medium and the following conclusions were drawn from the analyses. The differential settlement is reduced due to interaction and the performance of the mat depends on ${\kappa}_{sb}$ values. The moments $M_x$ and $M_y$ in the corner column at all the storey levels are higher in the case of the interaction analysis than in the conventional analysis. The axial forces in the peripheral columns increased and to that extent, the inner column axial loads are reduced. In the beam, more variation is seen in the support moments than in the span moments.

• Structural Engineering and Mechanics
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• v.30 no.2
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• pp.165-176
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• 2008

In this paper, a new iterative method for solving vehicle-bridge interaction problems is proposed. Iterative methods have advantages over the non-iterative methods in that it is not necessary to update the system matrix for a given wheel location, and the method can be applied for a new type of car or bridge with few or no modifications. In the proposed method, the necessity of system matrices update is eliminated using the equivalent interaction force acting on the bridge, which is obtained iteratively. Ballast stiffness is included in the interaction forces and the geometric compatibility at the contact points are used as convergence criteria. The bridge is considered as an elastic Bernoulli-Euler beam with surface irregularity and ballast stiffness. The moving vehicle is modeled as a multi-axle mass-spring-damper system having many degrees of freedom depending on the number of axles. The pitching effect, which is the interaction effect between the rear and front wheels when a vehicle begins to enter or leave the bridge, is also considered in the formulation including extended ground boundaries having surface irregularity and ballast stiffness. The applicability of the proposed method is illustrated in the numerical studies.

• Earthquakes and Structures
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• v.10 no.6
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• pp.1369-1389
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• 2016

The soil-structure interaction effect significantly influences the design of multi-storey buildings subjected to lateral seismic loads. The shear walls are often provided in such buildings to increase the lateral stability to resist seismic loads. In the present work, the nonlinear soil-structure analysis of a G+5 storey RC shear wall building frame having isolated column footings and founded on deformable soil is presented. The nonlinear seismic FE analysis is carried out using ANSYS software for the building with and without shear walls to investigate the effect of inclusion of shear wall on the moments in the footings due to differential settlement of soil mass. The frame is considered to behave in linear elastic manner, whereas, soil mass to behave in nonlinear manner. It is found that the interaction effect causes significant variation in the moments in the footings. The comparison of non-interaction and interaction analyses suggests that the presence of shear wall causes significant decrease in bending moments in most of the footings but the interaction effect causes restoration of the bending moments to a great extent. A comparison is made between linear and nonlinear analyses to draw some important conclusions.

• Steel and Composite Structures
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• v.6 no.3
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• pp.237-255
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• 2006

This paper presents a novel analytical formulation for the analysis of composite beams with partial shear interaction stiffened by a bolted longitudinal plate accounting for time effects, such as creep and shrinkage. The model is derived by means of the principle of virtual work using a displacement-based formulation. The particularity of this approach is that the partial interaction behaviour is assumed to exist between the top slab and the joist as well as between the joist and the bolted longitudinal stiffening plate, therefore leading to a three-layered structural representation. For this purpose, a novel finite element is derived and presented. Its accuracy is validated based on short-and long-term analyses for the particular cases of full shear interaction and partial shear interaction of two layers for which solutions in closed form are available in the literature. A parametric study is carried out considering different stiffening arrangements to investigate the influence on the short-and long-term behaviour of the composite beam of the shear connection stiffness between the concrete slab and the steel joist, the stiffness of the plate-to-beam connection, the properties of the longitudinal plate and the concrete properties. The values of the deflection obtained from the finite element simulations are compared against those calculated using the effective flexural rigidity in accordance with EC5 guidelines for the behaviour of elastic multi-layered beams with flexible connection and it is shown how the latter well predicts the structural response. The proposed numerical examples highlight the ease of use of the proposed approach in determining the effectiveness of different retrofitting solutions at service conditions.