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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Computational Structural Engineering Institute of Korea
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Journal DOI :
The Computational Structural Engineering Institute
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Volume & Issues
Volume 27, Issue 6 - Dec 2014
Volume 27, Issue 5 - Oct 2014
Volume 27, Issue 4 - Aug 2014
Volume 27, Issue 3 - Jun 2014
Volume 27, Issue 2 - Apr 2014
Volume 27, Issue 1 - Feb 2014
Selecting the target year
Similarity Analysis of Indonesia Caldera to Mount Baekdu
Lee, Sungsu ; Maharani, Yohana Noradika ; Yi, Waon-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 477~484
DOI : 10.7734/COSEIK.2014.27.6.477
Caldera is a large depression commonly formed by collapse of the ground following explosive eruption of a large body of stored magma. On earth, calderas and caldera complexes range in size from kilometers to tens of kilometers. Historical eruptions associated with caldera collapse have led to huge fatalities in Indonesia as well as left global impacts. This study presents case study on calderas in Indonesia which resembles to Mount Baekdu located at the border of China and North Korea; in the perspectives of similar characteristics, principal hazard, recent symptom of volcanic activity and the threat if eruption occurs in the near future. Calculation by using weighted evaluation matrix for Mount Krakatau, Mount Tambora, Mount Ijen, Tengger Caldera, Mount Rinjani and Ranau Caldera were taken for the selection of a site for future case study.
Assessment of Local Social Vulnerability in Facing Merapi Volcanic Hazard
Lee, Sungsu ; Maharani, Yohana Noradika ; Yi, Waon-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 485~492
DOI : 10.7734/COSEIK.2014.27.6.485
In regards to natural disasters, vulnerability analysis is a component of the disaster risk analysis with one of its objectives as a basis for planning priority setting activities. The volcano eruption raises many casualties and property in the surrounding area, especially when the volcano located in densely populated areas. Volcanic eruptions cannot be prevented, but the risk and vulnerability can be reduced which involve careful planning and preparations that anticipate a future crisis. The social vulnerability as social inequalities with those social factors can influence the susceptibility of various groups to harm and govern their ability to respond. This study carried out the methods of Social Vulnerability Index (SoVI) to measure the socially created vulnerability of the people living in Merapi proximal hamlets in Central Java, Indonesia that refers to the socioeconomic and demographic factors that affect the resilience of communities in order to describe and understand the social burdens of risk. Social vulnerability captured here, using a qualitative survey based-data such as interviews to local people with random ages and background to capture the answer vary, also interviews to stakeholders to help define social vulnerability variables. The paper concludes that by constructing the vulnerability index for the hamlets, the study reveals information about the distribution and causes of social vulnerability. The analysis using SoVI confirms that this method works well in ensuring that positive values indicating high social vulnerability and vice versa.
Fragility Assessment of Agricultural Facilities Subjected to Volcanic Ash Fall Hazards
Ham, Hee Jung ; Choi, Seung Hun ; Lee, Sungsu ; Kim, Ho-Jeong ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 493~500
DOI : 10.7734/COSEIK.2014.27.6.493
This paper presents findings from the assessment of the volcanic ash fragility for multi-hazard resisting vinyl greenhouse and livestock shed among the agricultural facilities. The volcanic ash fragility was evaluated by using a combination of the FOSM (first-order second-moment) method, available statistics of volcanic load, facility specifications, and building code. In this study, the evaluated volcanic ash fragilities represent the conditional probability of failure of the agricultural facilities over the full range of volcanic ash loads. For the evaluation, 6 types(ie., 2 single span, 2 tree crop, and 2 double span types) of multi-hazard resisting vinyl greenhouses and 3 types(ie., standard, coast, and mountain types) of livestock sheds are considered. All volcanic ash fragilities estimated in this study were fitted by using parameters of the GEV(generalized extreme value) distribution function, and the obtained parameters were complied into a database to be used in future. The volcanic ash fragilities obtained in this study are planning to be used to evaluate risk by volcanic ash when Mt. Baekdu erupts.
Propose of Capacity Spectrum Method by Nonlinear Earthquake Response Analysis
You, Jin-Sun ; Yang, Won-Jik ; Yi, Waon-Ho ; Kim, Hyoung-Joon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 501~508
DOI : 10.7734/COSEIK.2014.27.6.501
In this paper, a method on deducing the capacity spectrum based on nonlinear earthquake response analysis will be introduced. Damage assessment of general building draws the capacity spectrum through the Push-over analysis and the intersection point of capacity spectrum and demand spectrum is seen as performance point. Push-over analysis is the way to perform static analysis by using the equivalent static load changed from the effect of earthquake and predict the behavior of structures by earthquake. But, this method can not be taken into account in the effects of higher mode and the dynamic characteristic. Therefore, in order to calculate the capacity spectrum under dynamic properties of building. A capacity spectrum from going ahead with the nonlinear earthquake response analysis is suggested.
Seismic Fragility Functions for Steel Moment Resisting Frames using Incremental Dynamic Analyses
Lee, Seung-Won ; Yi, Waon-Ho ; Kim, Hyung-Joon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 509~516
DOI : 10.7734/COSEIK.2014.27.6.509
Accuracy of seismic response evaluated by a capacity spectrum method (CSM) is generally known to be less than that by Incremental dynamic analysis (IDA). In this paper, a procedure for IDA based seismic fragility curves for steel moment resisting frames was suggested. This study compares seismic fragility curves using the suggested method (IDA method) with those using a CSM and intends to verify the validity of the IDA method. The shapes of both seismic fragility curves are similar in slight and moderate damage states. However, in the case of extensive and complete damage states, the fragility curves obtained from the IDA method presents a more steep slope due to less variation (or uncertainties). This is due to the fact that the IDA method can properly capture the structural response beyond yielding rather than the CSM.
Annual Loss Probability Estimation of Steel Moment-Resisting Frames(SMRFs) using Seismic Fragility Analysis
Jun, Saemee ; Shin, Dong-Hyeon ; Kim, Hyung-Joon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 517~524
DOI : 10.7734/COSEIK.2014.27.6.517
The ultimate goal of seismic design is to reduce the probable losses or damages occurred during an expected earthquake event. To achieve this goal, this study represents a procedure that can estimate annual loss probability of a structure damaged by strong ground motion. First of all, probabilistic seismic performance assessment should be performed using seismic fragility analyses that are presented by a cumulative distribution function of the probability in each exceedance structural damage state. A seismic hazard curve is then derived from an annual frequency of exccedance per each ground motion intensity. An annual loss probability function is combined with seismic fragility analysis results and seismic hazard curves. In this paper, annual loss probabilities are estimated by the structural fragility curve of steel moment-resisting frames(SMRFs) in San Francisco Bay, USA, and are compared with loss estimation results obtained from the HAZUS methodology. It is investigated from the comparison that seismic losses of the SMRFs calculated from the HAZUS method are conservatively estimated. The procedure presented in this study could be effectively used for future studies related with structural seismic performance assessment and annual loss probability estimation.
A Parametric Study of Deflection Analysis of the Prestressed Concrete One-Way Slab for Serviceability Assessment
Park, Ha Eun ; Kim, Min Sook ; Lee, Young Hak ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 525~532
DOI : 10.7734/COSEIK.2014.27.6.525
The purpose of this study is to analyze the deflection for serviceability assessment of the prestressed concrete one-way slab using finite element program. Proposed finite element analysis method was verified comparing with existing experimental results, and it showed a good agreement. Also, a parametric study has been conducted to analyze the influence of concrete compressive strength, eccentricity, live load, and tendon profile. The finite element analysis results were compared with hand calculation results. Deflections were decreased as the concrete compressive strength increases, eccentricity increases, and the live load decreases. The deflection of straight tendon was smallest. And regression analysis has been conducted to analyze the correlation between parameters and camber.
A Comparison Study of Direct Impact Analysis of Vehicle to Concrete Pier and In-Direct Impact Analysis using Load-Time History Functions
Kim, WooSeok ; Kim, Kyeongjin ; Lee, Jaeha ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 533~542
DOI : 10.7734/COSEIK.2014.27.6.533
In design standards such as AASHTO LRFD and Korea Highway Bridge Design, the dynamic behaviors under the impact loading has not been considered and it recommends of using a static force for designing bridge column against vehicle collisions. Accordingly, in this study, models of vehicle collisions to concrete bridge column were developed with various boundary conditions in order to take into account dynamic behaviour of the column. Cargo trucks of 10tons, 16tons and 38tons were selected and a typical type of concrete bridge pier column along the Kyungbu highway in Korea was selected for this study. Results from this study indicate that the static load specified in the design standards are too small compared to results obtained in this study. It was also found that a consideration of the bridge superstructure allowed smaller damages of concrete bridge pier column under truck impact loadings. Furthermore, a comparison study of direct impact analysis of vehicle to bridge-column with in-direct impact analysis using load-time history functions was performed. The in-direct impact analysis shows that the use of load-time history graph improves the computational cost up to 92% and predict the behaviors of the bridge column under the impact loadings well. The obtained load-time history graph could be easily applied to several existing models.
Variability of Deflections for Reinforced Concrete Flat Plate
Kim, Min Sook ; Jo, Eunsun ; Lee, Young Hak ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 543~549
DOI : 10.7734/COSEIK.2014.27.6.543
The deflection of reinforced concrete members can be highly variable, due to uncertainties in the characteristics of the concrete. However, current standards do not take this problem into account, instead recommending only the minimum thickness and maximum allowable deflections based on empirical data. This paper is aimed at evaluation deflection variabilities by applying a probabilistic analysis model to a finite element analysis model. To evaluate the variabilities of deflections, a Monte Carlo simulation, which incorporated the eight parameters related to concrete, reinforcement, member size, and tension stiffening. The results showed that lager spans were more sensitive to the deflection due to loads and that as the applied live loads were increases and the slab thickness were decreased, the deflection variability increased.
Framework of Weapon Effectiveness Tool for Hardened Targets
Park, Jong Yil ; Lee, Sung Uk ; Kim, Ho Soo ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 551~555
DOI : 10.7734/COSEIK.2014.27.6.551
In this paper, framework of weapon effects calculator for hardened targets is presented. Fast running time, validation and easy expandibility are required for weaponeering tools, and these requirements were met by using of physics-based fast-running models or semi-empirical equations for damage prediction and penetrations, and modular architecture. Key concepts and outputs, required functions and corresponding use cases were presented.
Development of Unique Naming Algorithm for 3D Straight Bridge Model Using Object Identification
Park, Junwon ; Park, Sang Il ; Kim, Bong-Geun ; Yoon, Young-Cheol ; Lee, Sang-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 557~564
DOI : 10.7734/COSEIK.2014.27.6.557
In this study, we present an algorithm that conducts an unique naming process for the bridge object through the solid object identification focused on 3D straight bridge model. For the recognition of 3D objects, the numerical algorithm utilizes centroid point, and solid object on the local coordination system. It classifies the object feature set by classifying the objects and members based on the bridge direction. By doing so, unique names, which contain the information about span, members and order of the object, were determined and the suitability of this naming algorithm was examined through a truss bridge model and a bridge model with different coordinate systems. Also, the naming process based on the object feature set was carried out for the real 3D bridge model and then was applied to the module on local server and mobile device for real bridge inspection work. From the comparison of the developed naming algorithm based on object identification and the conventional one based on field inspection, it was shown that the conventional field inspection work can be effectively improved.
Application of Open Information Model for the Information Management on Building Flood Damage
Song, Min Sun ; Kim, Min-Su ; Lee, Sang-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 565~572
DOI : 10.7734/COSEIK.2014.27.6.565
A systematically structured 3D information model can be effectively utilized in many application fields. This study presents the methodology of generation and application of the city information model, which is suited for the management of the flood damage information. To ensure the interoperability and re-usability of the information, this study develops application methodology to utilize the information attributes included in the CityGML as an open standard data schema and extension methodology for additional information attributes. Also, an effective combining method for topography and building model was proposed. Using the data extracted from the combined information model based on a real flood damage case, it was shown that the numbers of casualties and isolation during a flood can be predicted and as a result, the applicability of the data model on flood damage estimation is naturally verified.
Three Dimensional Construction Stage Analysis and Deformation Monitoring of a Reinforced Concrete Highrise Building
Jeong, Daegye ; Yu, Eunjong ; Ha, Taehun ; Lee, Sungho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 573~580
DOI : 10.7734/COSEIK.2014.27.6.573
In this paper, axial strains and lateral displacements of columns in a 58-story reinforced concrete building were measured using vibrating wire gauge and laser scanner, respectively, and compared with predicted values. Predictions were obtained using ASAP, which is a 3D construction stage analysis program developed based on PCA report. Comparisons indicated that columns in the middle of floor plan showed good correlation with predictions. However, the columns in the corners showed some deviations. Lateral displacement of columns between measurement and estimation showed similar trends but considerable deviations, which are seemingly caused by construction error of column faces, and inaccuracy in differential vertical displacement prediction.
Estimation of Initial Tensile Force Acting on Tendon using the Deformation of a Multi-tendon Anchor Head
Park, Jang Ho ; Cho, Jeong-Rae ; Park, Jaegyun ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 581~588
DOI : 10.7734/COSEIK.2014.27.6.581
The PSC bridges have recently been widely used in Korea. The PSC bridge is a structure whose performance is improved through the use of tendons and steel bars in deflection and cracking characteristics of the concrete. Therefore, measurement or estimation of the load acting on tendon is important in order to maintain the PSC bridges efficiently and safely. This paper deals with a numerical study on the deformation of a multi-tendon anchor head in order to verify the relationship between the load acting on tendon and the deformation of anchor head. All kinematics, material properties and contact nonlinearity are included for the precise analysis and numerical studies are performed by Abaqus. From the numerical results, it is verified that the hoop strain is most useful in the estimation of the load acting on tendon and strains are affected by various parameters such as friction coefficient, boundary conditions, and arrangement.
Dynamical Predictions of the Structural Connection by the Reduced Approach
Yun, Seong-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 589~596
DOI : 10.7734/COSEIK.2014.27.6.589
Joints, fasteners or connected parts frequently have a significant effect on the dynamical behavior of assembled mechanical structures. Therefore, the analytical prediction of structural responses depends on the accuracy of joint modeling. This paper deals with the formulation and analysis of dynamic mechanism for joint flexibilities whose relevant magnitudes of stiffnesses are investigated by using linear and torsional springs. The equation of motion is derived by using a generic joint in the middle of clamped-clamped beam. A reanalysis due to changes in magnitudes of joint stiffnesses is based on the reduced analysis where the binomial series terms are used as basis vectors. The solution procedures are straightforward and the method can be readily used with a general finite element method. The computational effort needed by this approach is usually much smaller than the effort needed for complete vibration analysis. Two numerical examples show that accurate results are obtained efficiently by reducing the number of degree in the reduced model.
A Study of the Implementation of Wireless Sensor Network based Entrance Control Management Systems on the Hazard Area
Kim, Dae-Soek ; Lee, Kyung-Ho ; Lee, Jung-Min ; Nam, Byeong-Wook ; Park, Kae-Myoung ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 597~603
DOI : 10.7734/COSEIK.2014.27.6.597
The cargo of ships and offshore structures is the number of oil of combustibility and volatile, oil processing cargo. Furthermore heavy cargo of the vehicle or container box or bulk cargo are occupied the remainder of cargo. In addition, there is a possibility to move the location of the cargo and the vessel because it is received periodic / non-periodic a load of wave and ocean current. Therefore a shipboard hazard is much greater than onshore industry hazard. Monitoring and preparation for safety are necessary things because there is always risk of accidents arise from the impact of the freight and cargo of ships and offshore structures. In this study, we conducted a study with respect to the introduction of the wireless sensor network monitoring system to ensure the safety of the crew and workers on shipboard.
Comparison among Methods of Modeling Epistemic Uncertainty in Reliability Estimation
Yoo, Min Young ; Kim, Nam Ho ; Choi, Joo Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 605~613
DOI : 10.7734/COSEIK.2014.27.6.605
Epistemic uncertainty, the lack of knowledge, is often more important than aleatory uncertainty, variability, in estimating reliability of a system. While the probability theory is widely used for modeling aleatory uncertainty, there is no dominant approach to model epistemic uncertainty. Different approaches have been developed to handle epistemic uncertainties using various theories, such as probability theory, fuzzy sets, evidence theory and possibility theory. However, since these methods are developed from different statistics theories, it is difficult to interpret the result from one method to the other. The goal of this paper is to compare different methods in handling epistemic uncertainty in the view point of calculating the probability of failure. In particular, four different methods are compared; the probability method, the combined distribution method, interval analysis method, and the evidence theory. Characteristics of individual methods are compared in the view point of reliability analysis.
Study on Structural Strength of Mark III type LNG Cargo Containment System by Idealized Triangular Impulse Load
Hwang, Se Yun ; Kim, Sung Chan ; Lee, Jang Hyun ; Nho, In Sik ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 615~624
DOI : 10.7734/COSEIK.2014.27.6.615
It has been well known the sloshing pressure has complex shape and various patterns. The pattern of sloshing pressure is variously characterized by the pressure amplitude, duration time and skewness. The structural response induced by the sloshing pressure is also affected by the pattern of sloshing pressure and the type of structural members. In order to understand the structural response by the perspective view of categorized pattern, it is more efficient to make simple sloshing pressure pattern than to reflect the complex pressure history. In this study, the sloshing pressures obtained by the small scale model test are simplified with respect to their duration and skewness. Dynamic analyses of Mark-III LNG CCS are then parametrically performed with the consideration of various types of sloshing impact. Meanwhile, the failure pressures given the duration and skewness are investigated after parametric calculations are conducted to investigate the effect of pressure parameters on the structural response.
Strength Analysis for the Plate System of the Mark III Cargo Containment
Jeong, Han-Koo ; Yang, Young-Soon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 625~633
DOI : 10.7734/COSEIK.2014.27.6.625
Mark III CCS plate is considered in this paper to perform its strength assessment. Mark III CCS plate is designed and constructed by stacking various non-metallic engineering materials such as plywood, triplex and reinforced PU foam that are supported by series of mastic upon inner steel hull structure. From the viewpoint of structural analysis, this plated structure is treated as a laminated anisotropic structure. Commercially available general purpose finite element analysis programs such as MSC PATRAN and MARC are used to develop the finite element (FE) model of the Mark III CCS plate. Because of the characteristics of LNG cargo that the Mark III CCS plate deals with, it is subjected to a wide range of temperature variations, i.e. about
. Different material properties of the Mark III CCS plate at these temperature levels are considered in the FE model. Using the developed FE model, strength assessment procedure is developed incorporating various anisotropic failure criteria such as Hashin, Hill, Hoffman, Maximum stress and Tsai-Wu. The strength assessment is performed within the initial failure state of the Mark III CCS plate and, as a result, failure details such as failure locations and loads are identified.
Reliability Prediction of Failure Modes due to Pressure in Solid Rocket Case
Kim, Dong-Seong ; Yoo, Min-Young ; Kim, Hee-Seong ; Choi, Joo-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 635~642
DOI : 10.7734/COSEIK.2014.27.6.635
In this paper, an efficient technique is developed to predict failure probability of three failure modes(case rupture, fracture and bolt breakage) related to solid rocket motor case due to the inner pressure during the mission flight. The overall procedure consists of the steps: 1) design parameters affecting the case failure are identified and their uncertainties are modelled by probability distribution, 2) combustion analysis in the interior of the case is carried out to obtain maximum expected operating pressure(MEOP), 3) stress and other structural performances are evaluated by finite element analysis(FEA), and 4) failure probabilities are calculated for the above mentioned failure modes. Axi-symmetric assumption for FEA is employed for simplification while contact between bolted joint is accounted for. Efficient procedure is developed to evaluate failure probability which consists of finding first an Most Probable Failure Point(MPP) using First-Order Reliability Method(FORM), next making a response surface model around the MPP using Latin Hypercube Sampling(LHS), and finally calculating failure probability by employing Importance Sampling.
Evaluation of Reliability Index of Governing Load Combination for Design of Cable Supported Bridge Members
Paik, Inyeol ; Yoon, Taeyong ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 643~651
DOI : 10.7734/COSEIK.2014.27.6.643
In this paper the reliability analyses of the cable-supported bridge design code which is recently issued in Korea are performed and the results are presented. Governing load combinations for the member design and the statistical properties of the main members are introduced and the analysis is performed using an example cable-stayed bridge for which the design is performed following the load and resistance factors defined in the design code. The reliability analysis shows the target reliability index can be achieved by applying load and resistance factors and the application of the resistance modification factor can enhance the reliability level if the importance of the bridge needs to be increased. The sensitivity analysis reveals that decreasing uncertainty of the cable strength is critical for obtaining the target reliability index. The study results show that the design using the load and resistance factors of the code can achieve the target reliability indexes for the design of cable supported bridge.
Evaluation Criteria of Attributes of Classes and Objects of Data Repositories for Structural Experiment Information
Lee, Chang-Ho ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 653~662
DOI : 10.7734/COSEIK.2014.27.6.653
The data repositories for structural experiment information needs to be efficient to use in order to allow structural engineers and researchers to store and retrieve easily the information involved in the structural experiments. The data repositories can be evaluated in terms of the organization of the data repositories themselves and of the organization of the actual experiment information in the data repositories, which can be represented using classes and objects with their attributes. This paper proposes the evaluation criteria of attributes of the classes and objects. The evaluation criteria of the attributes of the classes, such as the number of attributes in class and the numbers of the data-valued and object entity-valued attributes, are used for understanding the complexity of the organization of the data repositories. The evaluation criteria of the attributes of the objects, such as the number of valued attributes in object, are used for describing how the actual experiment information is stored through the levels in the data repositories for the structural experiment information.
Analytical Models of Beam-Column joints in a Unit Modular Frame
Choi, Kyung-Suk ; Kim, Hyung-Joon ;
Journal of the Computational Structural Engineering Institute of Korea, volume 27, issue 6, 2014, Pages 663~672
DOI : 10.7734/COSEIK.2014.27.6.663
Recently, modular structural systems have been applicable to building construction since they can significantly reduce building construction time. They consists of several unit modular frames of which each beam-column joint employs an access hole for connecting unit modular frames. Their structural design is usually carried out under the assumption that their load-carrying mechanism is similar to that of a traditional steel moment-resisting system. In order to obtain the validation of this assumption, the cyclic characteristics of beam-column joints in a unit modular frame should be investigate. This study carried out finite element analyses(FEM) of unit modular frames to investigate the cyclic behavior of beam-column joints with the structural influence of access holes. Analysis results show that the unit modular frames present stable cyclic response with large deformation capacities and their joints are classified into partial moment connections. Also, this study develops a simple spring model for earthquake nonlinear analyses and suggests the Ramberg-Osgood hysteretic rule to capture the cyclic response of unit modular frames.