• Journal of Advanced Marine Engineering and Technology
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• v.18 no.5
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• pp.68-77
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• 1994

The authors apply the transfer influence coefficient method to the 3-dimensional vibration analysis of beam with multi-joints and formulate a general algorithm to analysis the longitudinal, flexural and torsional coupled free vibration. In this paper, the structure, which is mainly founded in the robot arms, cranes and so on, has some crooked parts, subsystems and joints but has no closed loop in this system. It is modeled as the beam of a distributed mass system with massless translational, rotational and torsional springs in each node, and joint elements of release or roll at which node the displacement vector is discontinuous. The superiorty of the present method to the transfer matrix method in the computation accuracy was confirmed by the numerical computation results. Moreover, we confirmed that boundary and intermediate conditions could ve controlled by varying the values o the spring constants.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.3
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• pp.256-266
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• 1997

The authors apply the transfer influence coefficient method to the 3. dimensional vibration analysis of beam with multi - joints and formulate a general algorithm to analyse the longitudinal, flexural and torsional coupled forced vibration. In this paper, a structure which is mainly found in the robot arms, cranes and so on, has some crooked parts, subsystems and joints, but has no closed loop in this system. It is modeled as the beam of a distributed mass system with massless translational, rotational and torsional springs in each node, and joint elements of release or roll at node which the displacement vector is discontinuous. The superiority of the present method to the transfer matrix method in the computation accuracy was confirmed from the numerical computation results. Moreover, we confirmed that boundary and intermediate conditions could be controlled by varying the values of the spring constants.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.23 no.11 s.170
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• pp.2058-2066
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• 1999

The present paper proposes a new dynamic analysis method for multi-span Timoshenko beam structures supported by joints with damping subject to moving loads. An exact dynamic element matrix method is adopted to model Timoshenko beam structures. A generalized modal analysis method is applied to derive response formulae for beam structures subject to moving loads. The proposed method offers an exact and closed form solution. Two numerical examples are provided for validating and illustrating the proposed method. In the first numerical example, a single span beam with multiple moving loads is considered. A dynamic analysis on a multi-span beam under a moving load is considered as the second example, in which the flexibility and damping of supporting joints are taken into account. The numerical study proves that the proposed method is useful for the vibration analysis of multi-span beam-hype structures by moving loads.

• Earthquakes and Structures
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• v.20 no.1
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• pp.29-38
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• 2021

According to ACI 224.3R-95 (ACI, 2013), construction joints (cold joint) in the column are to be provided at the top of floor slab for column continuing to the next floor and underside of floor slab and beam. A recent study reveals that providing cold joint of the mentioned location significantly reduced the seismic performance of the frame structures. Since, the construction joints in multi-story frame structures normally provided at the top of the floor slabs and at soffit of the beam in the column. This study investigated the effect of construction joint at various location in the column of beam-column joint such as at the top of floor slab, soffit level of the beam, half the depth of beam below the soffit of the beam and at a full depth of the beam below the soffit of the beam. The study revealed that there is an improvement in seismic capacity of the specimens as the location of cold joint is placed away from the soffit of the beam for lower story column.

• Steel and Composite Structures
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• v.46 no.6
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• pp.823-837
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• 2023

This paper presents the seismic performance of seven beam-column joints with an eccentricity between beam depths under cyclic loadings. The failure modes of the panel zone were divided into two types. One was the shear force failure that appeared in the entire panel zone (SFEPZ), the other was the shear force failure that appeared in the partial panel zone (SFPPZ). Seven finite element models were established using multi-scale methods. Compared with the experimental specimens, the hysteretic loops exhibited a similar trend. The multi-scale models could accurately simulate the experimental results. Furthermore, the calculation formulas of yield and plastic shear capacity of unequal-depth joints with outer annular stiffener were proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.203-209
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• 1996

The authors apply the transfer influence coefficient method to the 3-dimensional vibration analysis of beam with multi-joints and formulate a general algorithm to analysis the longitudinal, flexural and torsional coupled forced vibration. In this paper, a structure, which is mainly founded in the robot arms, cranes and so on, has some crooked parts, subsystems and joints but has no closed loop in this system. It is modeled as the beam of a distributed mass system with massless translational, rotational and torsional springs in each node, and joint elements of release or roll at which node the displacement vector is discontinuous. The superiority of the present method to the transfer matrix method in the computation accuracy was confirmed from the numerical computation results. Moreover, we confirmed that boundary and intermediate conditions could be controlled by varying the values of the spring constants.

• Structural Engineering and Mechanics
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• v.38 no.1
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• pp.27-37
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• 2011

This paper presents the results of a study on the capability of nonlinear quasi-static finite element modelling in simulating the hysteretic behaviour of CFRP and GFRP-retrofitted RC exterior beam-column joints under cyclic loads. Four specimens including two plain and two CFRP/GFRP-strengthened beam-column joints tested by Mahini and Ronagh (2004) and other researchers are modelled using ANSYS. Concrete in compression is defined by the modified Hognestad model and anisotropic multi-linear model is employed for modelling the stress-strain relations in reinforcing bars while anisotropic plasticity is considered for the FRP composite. Both concrete and FRP are modelled using solid elements whereas space link elements are used for steel bars considering a perfect bond between materials. A step by step load increment procedure to simulate the cyclic loading regime employed in the testing. An automatically reforming stiffness matrix strategy is used in order to simulate the actual seismic performance of the RC concrete after cracking, steel yielding and concrete crushing during the push and pull loading cycles. The results show that the hysteretic simulation for all specimens is satisfactory and therefore suggest that the numerical model can be used as an inexpensive tool to design of FRP-strengthened RC beam-column joints under cyclic loads.

• Steel and Composite Structures
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• v.26 no.5
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• pp.621-634
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• 2018

Flush end-plate (FEP) beam-to-column joints are commonly used for gravity load resisting parts in steel multi-storey buildings. However, in seismic resisting structures FEP joints should also provide rotation capacity consistent with the global structural displacements. The current version of EN1993-1-8 recommends a criterion aiming at controlling the thickness of the end-plate in order to avoid brittle failure of the connection, which has been developed for monotonic loading conditions assuming elastic-perfectly plastic behaviour of the connection's components in line with the theory of the component method. Hence, contrary to the design philosophy of the hierarchy of resistances implemented in EN1998-1, the over strength and the hardening of the plastic components are not directly accounted for. In light of these considerations, this paper describes and discusses the results obtained from parametric finite element simulations aiming at investigating the moment-rotation response of FEP joints under cyclic actions. The influence of bolt diameter, thickness of end-plate, number of bolt rows and shape of beam profile on the joint response is discussed and design requirements are proposed to enhance the ductility of the joints.

• Structural Engineering and Mechanics
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• v.45 no.4
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• pp.423-437
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• 2013

Complex structures are usually assembled from several substructures with joints connecting them together. These joints have significant effects on the dynamic behavior of the assembled structure and must be accurately modeled. In structural analysis, these joints are often simplified by assuming ideal boundary conditions. However, the dynamic behavior predicted on the basis of the simplified model may have significant errors. This has prompted the researchers to include the effect of joint stiffness in the structural model and to estimate the stiffness parameters using inverse dynamics. In the present work, structural joints have been modeled as a pair of translational and rotational springs and frequency equation of the overall system has been developed using sub-structure synthesis. It is shown that using first few natural frequencies of the system, one can obtain a set of over-determined system of equations involving the unknown stiffness parameters. Method of multi-linear regression is then applied to obtain the best estimate of the unknown stiffness parameters. The estimation procedure has been developed for a two parameter joint stiffness matrix.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.688-693
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• 2007

Most frame structures cannot be manufactured in a single-piece form. Ideally, when a structure is built up by assembling multi pieces, assembly at the joints should be rigidly performed enough to have almost full stiffness, which is difficult for practical reasons such as manufacturing cost and time. In this research, we aim to develop a manufacturability-oriented compliance-minimizing topology optimization using a ground beam model incorporating additional zero-length elastic joint elements. In the present formulation, design variables control the stiffness of zero-length elastic joints, not the stiffness of beams. Because joint stiffness values at the converged state can be utilized to select candidate assembly locations and their strengths, the technique is extremely useful to design multi-piece frame structures. An optimal layout is also extracted based on the stiffness values.