• Structural Engineering and Mechanics
• /
• v.81 no.1
• /
• pp.11-28
• /
• 2022

This paper considers the combination of cyclic and axial loads to investigate the hysteretic performance of H-section 6061-T6 aluminum alloy members. The hysteretic performance of aluminum alloy members is the basis for the seismic performance of aluminum alloy structures. Despite the prevalence of aluminum alloy reticulated shells structures worldwide, research into the seismic performance of aluminum alloy structures remains inadequate. To address this deficiency, we design and conduct cyclic axial load testing of three H-section members based on a reliable testing system. The influence of slenderness ratios and bending direction on the failure form, bearing capacity, and stiffness degradation of each member are analyzed. The experiment results show that overall buckling dominates the failure mechanism of all test members before local buckling occurs. As the load increases after overall buckling, the plasticity of the member develops, finally leading to local buckling and fracture failure. The results illustrate that the plasticity development of the local buckling position is the main reason for the stiffness degradation and failure of the member. Additionally, with the increase of the slenderness ratio, the energy-dissipation capacity and stiffness of the member decrease significantly. Simultaneously, a finite element model based on the Chaboche hybrid strengthening model is established according to the experiment, and the rationality of the constitutive model and validity of the finite element simulation method are verified. The parameter analysis of twenty-four members with different sections, slenderness ratios, bending directions, and boundary conditions are also carried out. Results show that the section size and boundary condition of the member have a significant influence on stiffness degradation and energy dissipation capacity. Based on the above, the appropriate material constitutive relationship and analysis method of H-section aluminum alloy members under cyclic loading are determined, providing a reference for the seismic design of aluminum alloy structures.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.38 no.2
• /
• pp.349-356
• /
• 2018

This paper attempts to develop a connection model based on FE analysis that can be applied to the evaluation of earthquake fragility of Steel Storage Racks lacking research in Korea. In order to accomplish this goal, shaking table tests, modal tests, and various member tests (8 case, push-over test) for structural members have been conducted to understand the behavior of steel storage racks. Based on the experimental results, detailed modeling of the joints was conducted using the NX-Nastran program in order to develop a connection model for Steel storage racks to be applied to the seismic vulnerability assessment. Especially, surface to surface contact element and spring element are applied to simulate the connection between the column member and the beam member connected by the simple latch method. Spring element model developed and applied ARX (Auto Regressive eXogenous) based mathematical model. The simulation results based on the FE model showed excellent reliability with a mutual error rate of less than 8% when compared with the member test results. As a result, it was confirmed that the FE model based connection model developed in the study can be applied to the analytical model for the seismic vulnerability assessment of Steel storage racks.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.4
• /
• pp.450-457
• /
• 2020

In this study, engineering characteristics such as flowability, segregation and compressive strength by age to derive fast hardening material mixing proportion using excavated soil. And based on optimal mixing proportion, field simulation experiment conducted in laboratory to examine the effectiveness of the method such as kelly ball drop test and soil penetration test for reviewing the following process. As as a result of evaluation, in case of kelly ball drop test and soil penetration test were securing the following process initiation time 3 hours after place CLSM. As results of these assessments, kelly ball drop test and soil penetration test were applicable for revewing following process in construction field besides unconfined compressive strength method.

• Structural Engineering and Mechanics
• /
• v.40 no.4
• /
• pp.517-539
• /
• 2011

This paper presents the seismic responses of a 1:5-scale five-story reinforced concrete building model, which represents a residential apartment building that has a high irregularity of weak story, soft story, and torsion simultaneously at the ground story. The model was subjected to a series of uni- and bi-directional earthquake simulation tests. Analysis of the test results leads to the following conclusions: (1) The model survived the table excitations simulating the design earthquake with the PGA of 0.187 g without any significant damages, though it was not designed against earthquakes; (2) The fundamental mode was the torsion mode. The second and third orthogonal translational modes acted independently while the torsion mode showed a strong correlation with the predominant translational mode; (3) After a significant excursion into inelastic behavior, this correlation disappeared and the maximum torsion and torsion deformation remained almost constant regardless of the intensity of the two orthogonal excitations; And, (4) the lateral resistance and stiffness of the critical columns and wall increased or decreased significantly with the large variation of acting axial forces caused by the high bi-directional overturning moments and rocking phenomena under the bi-directional excitations.

• Geomechanics and Engineering
• /
• v.4 no.1
• /
• pp.39-53
• /
• 2012

Due to strong ground motion of earthquake, the material in the landslide can travel a significant distance from the source. A new landslide model called Multiplex Acceleration Model (MAM) has been proposed to interpret the mechanism of long run-out movement of this type of landslide, considering earthquake behaviors on slope and landslide materials. In previous study, this model was verified by a shaking table test. However, there is a scale limitation of shaking table test to investigate MAM in detail. Thus, numerical simulation was carried out in this study to validate MAM under full scale. A huge rock ejected and A truck threw upwards by seismic force during Wenchuan Earthquake (Ms. 8.0) was discussed based on the simulation results. The results indicate that collisions in P-phase of earthquake and trampoline effect are important behaviors to interpret the mechanism of long run-out and high velocity. The results show that MAM is acceptable and applicable.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1998.04a
• /
• pp.596-601
• /
• 1998

Rubber has been widely used as a good device for reducing the vibration in various fields including the anti seismic device like LRB. The damping characteristic is needed to be mathematically modeled to predict the dynamic behavior of the isolated system. In this paper, The frequency response function was obtained experimentally by the resonant method and simulation was performed with the hysteretic model using the resonant test result. the hysteretic behavior of the rubber can be explained by the change of the static stiffness obtained in the DC by the concept of the transfer function.

• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2001.09a
• /
• pp.364-372
• /
• 2001

An orifices fluid damper(OFD) having the capacity of about 2 tons was designed and fabricated and applied to a 6-story steel structure under random excitation and seismic excitation for the confirmation of its validity on structural vibration absorbtion. The experimental results demonstrated that the addition of an OFD to the test structure is very effective in reduction of vibration level of the higher modes as well as the fundamental mode. Maxwell model was adopted to described the frequency-dependent characteristics of the fabricated OFD and the numerical simulation was carried for the test structure. It was confirmed that the experimental and numerically simulated results agree well.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.12 no.6
• /
• pp.469-477
• /
• 2002

An orificed fluid damper(OFD) having the capacity of about 2 tons was designed and fabricated, and series of tests were performed to grasp the fundamental performance characteristics of it. Several important findings were observed and introduced in this paper. It was applied to a 6-story steel structure under random excitation and seismic excitation for the confirmation of its validity on structural vibration absolution. The experimental results demonstrated that the addition of an OFD to the test structure is very effective in reduction of vibration level of the higher modes as well as the fundamental mode. Maxwell model was adopted to describe the frequency-dependent characteristics of the fabricated OFD and the numerical simulation was carried for the test structure. It was confirmed that the experimentally and numerically simulated results agree well.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.27 no.6
• /
• pp.22-29
• /
• 2023

In the evaluation of seismic performance for structural materials and components, the loading rate and axial force can have a significant impact. Due to time-delay effects between input and output displacements, It is difficult to apply high-rate displacement in cyclic tests and hybrid simulations. Additionally, the difficulty of maintaining a consistent vertical load in the presence of lateral displacement has limited fast and real-time tests performed while maintaining a constant vertical load. In this study, slow, fast cyclic tests and real-time hybrid simulations were conducted to investigate the rate dependency and the influence of vertical loads of Isolation Bearing. In the experiment, the FLB System including an Adaptive Time Series (ATS) compensation and a state estimator was constructed for real-time control of displacement and vertical load. It was found that the vertical load from the superstructure and loading rate can have a significant impact on the strength of the seismic isolation bearing and its behavior during an earthquake. When conducting experiments for seismic performance evaluation, they must be implemented to be similar to reality. This study demonstrates the excellent performance of the system built and used for seismic performance evaluation and enables accurate and efficient seismic performance evaluation.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.10 no.3 s.49
• /
• pp.149-158
• /
• 2006

The reduced beam section (RBS) steel moment connection has performed well in past numerous tests. However there still remain several design issues that should be further examined. One such issue on RBS connection performance is the panel zone strength. Although a significant amount of test data are available, a specific recommendation for a desirable range of panel zone strength versus beam strength has yet to be proposed. In this paper, the effects of panel zone strength on the cyclic performance of RBS connection are investigated based on the available test database from comprehensive independent testing programs. A criterion for a balanced panel zone strength that assures sufficient plastic rotation capacity while reducing the amount of beam buckling is proposed. Numerical studies to supplement the test results are then presented based on the validated finite element analysis. Satisfactory numerical simulation achieved in this study also indicates that numerical analysis based on quality finite element modeling can supplement or replace, at least in part, the costly full-scale cyclic testing of steel moment connections.