• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.961-967
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• 2012

The metal is frequently used in the air-conditioner frame, which must have the durability from the various external environments, but has difficulties in being manufactured for many complex shapes. On the other hand, the plastic, used as a material of injection molding, enables the realization of various shapes and the mass-production of complex ones and leads low production cost. As the air-conditioner frame becomes increasingly complex and detailed, the plastic material is highlighted as an alternative for the frame. But the product molded by plastic with a complex shape might have a noise problem. Therefore this study attempts to design the product through TRIZ in order to reduce the noise of the air-conditioner with the frame of plastic material.

• Structural Engineering and Mechanics
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• v.10 no.4
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• pp.371-392
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• 2000

Application of "advanced analysis" methods suitable for non-linear analysis and design of steel frame structures permits direct and accurate determination of ultimate system strengths, without resort to simplified elastic methods of analysis and semi-empirical specification equations. However, the application of advanced analysis methods has previously been restricted to steel frames comprising only compact sections that are not influenced by the effects of local buckling. A concentrated plasticity method suitable for practical advanced analysis of steel frame structures comprising non-compact sections is presented in this paper. The pseudo plastic zone method implicitly accounts for the effects of gradual cross-sectional yielding, longitudinal spread of plasticity, initial geometric imperfections, residual stresses, and local buckling. The accuracy and precision of the method for the analysis of steel frames comprising non-compact sections is established by comparison with a comprehensive range of analytical benchmark frame solutions. The pseudo plastic zone method is shown to be more accurate and precise than the conventional individual member design methods based on elastic analysis and specification equations.

• Computers and Concrete
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• v.19 no.6
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• pp.689-699
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• 2017

An energy-based approach for determining earthquake safety of reinforced concrete frame structures is presented. The developed approach is based on comparison of plastic energy capacities of the structures with plastic energy demands obtained for selected earthquake records. Plastic energy capacities of the selected reinforced concrete frames are determined graphically by analyzing plastic hinge regions with the developed equations. Seven earthquake records are chosen to perform the nonlinear time history analyses. Earthquake plastic energy demands are determined from nonlinear time history analyses and hysteretic behavior of earthquakes is converted to monotonic behavior by using nonlinear moment-rotation relations of plastic hinges and plastic axial deformations in columns. Earthquake safety of selected reinforced concrete frames is assessed by using plastic energy capacity graphs and earthquake plastic energy demands. The plastic energy dissipation capacities of the frame structures are examined whether these capacities can withstand the plastic energy demands for selected earthquakes or not. The displacements correspond to the mean plastic energy demands are obtained quite close to the displacements determined by using the procedures given in different seismic design codes.

• Computers and Concrete
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• v.32 no.5
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• pp.527-541
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• 2023

This paper emphasizes the use of CFT columns in frame structures subjected to strong horizontal forces and shows that the efficiency of using CFT columns is increased when the plastic design approach is adopted. Because the plastic design approach is based on redistribution of the force of the internal member, a double node for the rotational degrees of freedom, where the adjacent two rotational degrees of freedom can be connected by a non-dimensional spring element, is designed and implemented into the formulation. In addition, an accompanying criterion is considered in order to make it possible to describe the continuous moment redistribution in members connected to a nodal point up to a complete plastic state. The efficiency of CFT columns is reviewed in comparison with RC columns in terms of the cost and the resistance capacity, as defined by a P-M interaction diagram. Three representative frame structures are considered and the obtained results show that the most efficient and economical design can be expected when the use of CFT columns is considered on the basis of the plastic design, especially when a frame structure is subjected to significant horizontal forces, as in a high-rise building.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.251-267
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• 1991

Plastic strength analysis using plastic failure mode as a limit state is adopted instead of a conventional elastic structural analysis to predict the ultimate strength of Web frame idealized by a plane frame. Linear programming arid Compact procedure are developed for determining the collapse load factor. It is found that the final results are good agreement with the results of Elasto-plastic analysis. Besides, the redundant structures like Web frame is known to have multiple failure modes. Web frame may collapse under any of the possible failure modes. Thus, the identification of these possible failure modes is necessary and very important in the reliability analysis of Web frame. In order to deal with multiple failure modes, automatic generation method of all failure modes and basic failure modes is used for selecting the dominant failure modes. The probability of failure pastic collapse of Web frame is calculated using these dominant failure modes. The safety of Web frame is asscssed and compared by performing the deterministic and probabilistic analysis.

• Steel and Composite Structures
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• v.22 no.2
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• pp.235-255
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• 2016

This paper experimentally investigated the behavior of steel frame structures of traditional-style buildings subjected to combined constant axial load and reversed lateral cyclic loading conditions. The low cyclic reversed loading test was carried out on a 1/2 model of a traditional-style steel frame. The failure process and failure mode of the structure were observed. The mechanical behaviors of the steel frame, including hysteretic behaviors, order of plastic hinges, load-displacement curve, characteristic loads and corresponding displacements, ductility, energy dissipation capacity, and stiffness degradation were analyzed. Test results showed that the Dou-Gong component (a special construct in traditional-style buildings) in steel frame structures acted as the first seismic line under the action of horizontal loads, the plastic hinges at the beam end developed sufficiently and satisfied the Chinese Seismic Design Principle of "strong columns-weak beams, strong joints-weak members". The pinching phenomenon of hysteretic loops occurred and it changed into Z-shape, indicating shear-slip property. The stiffness degradation of the structure was significant at the early stage of the loading. When failure, the ultimate elastic-plastic interlayer displacement angle was 1/20, which indicated high collapse resistance capacity of the steel frame. Furthermore, the finite element analysis was conducted to simulate the behavior of traditional-style frame structure. Test results agreed well with the results of the finite element analysis.

• Korean Institute of Interior Design Journal
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• v.16 no.2 s.61
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• pp.115-122
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• 2007

The purpose of this study is to extract design concepts, especially in relation to light, as a part of extracting design concepts in architectural interior design. This study consists of two steps. Firstly, appropriate design concepts are extracted from various design characteristics. Secondly, these concepts are classified in the frame of other components of architectural space, as well as in the frame of the plastic characteristics of light. Various design characteristics were analyzed, those of which relating to the plastic character of space, namely, visual phenomenon. As a result of the analysis, 32 concepts were extracted. These concepts, in the frame of other components of architectural space (space, form, structure, opening of space, material, color, inside & outside relationship), were classified, as well as In the frame of the plastic character of Light (transparency, perception, direction, ornament). As the results of this research, the suggested design concepts will be a study material, available to the interior designers as well as students who want to utilize the organized study concepts.

• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.65-72
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• 2013

This paper describes a finite element analysis (FEA) of the body frame of a subsea robot, Crabster200 (CR200). CR200 has six legs for mobility instead of screw type propellers, which distinguishes it from previous underwater robots such as remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs). Another distinguishing characteristic is the body frame, which is made of carbon fiber reinforced plastic (CFRP). This body frame is designed as a rib cage structure in order to disperse the applied external loads and reduce the weight. The frame should be strong enough to support many devices for exploration and operation underwater. For a reasonable FEA, we carried out specimen tests. Using the obtained material properties, we performed a modal analysis and FEA for CR200 with a ready posture. Finally, this paper presents the FEA results for the CFRP body frame and the compares the characteristics of CFRP with conventional material, aluminum.

• Structural Engineering and Mechanics
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• v.9 no.3
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• pp.241-256
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• 2000

The major sources of energy dissipation in steel frames with partially restrained (PR) connections are evaluated. Available experimental results are used to verify the mathematical model used in this study. The verified model is then used to quantify the energy dissipation in PR connections due to hysteretic behavior, due to viscous damping and at plastic hinges if they are formed. Observations are made for two load conditions: a sinusoidal load applied at the top of the frame, and a sinusoidal ground acceleration applied at the base of the frame representing a seismic loading condition. This analytical study confirms the general behavior, observed during experimental investigations, that PR connections reduce the overall stiffness of frames, but add a major source of energy dissipation. As the connections become stiffer, the contribution of PR connections in dissipating energy becomes less significant. A connection with a T ratio (representing its stiffness) of at least 0.9 should not be considered as fully restrained as is commonly assumed, since the energy dissipation characteristics are different. The flexibility of PR connections alters the fundamental frequency of the frame. Depending on the situation, it may bring the frame closer to or further from the resonance condition. If the frame approaches the resonance condition, the effect of damping is expected to be very important. However, if the frame moves away from the resonance condition, the energy dissipation at the PR connections is expected to be significant with an increase in the deformation of the frame, particularly for low damping values. For low damping values, the dissipation of energy at plastic hinges is comparable to that due to viscous damping, and increases as the frame approaches failure. For the range of parameters considered in this study, the energy dissipations at the PR connections and at the plastic hinges are of the same order of magnitude. The study quantitatively confirms the general observations made in experimental investigations for steel frames with PR connections; however, proper consideration of the stiffness of PR connections and other dynamic properties is essential in predicting the dynamic behavior.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.327-334
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• 2001

This paper presents a non-linear analysis procedure for plane frame structures by finite element formulation with assumptions of Timoshenko beam theory. Finite element displacement method based on Lagrangian formulation is used and two-noded and isoparametric line element is adopted to represent finite element model. The layered approach is used for the elasto-plastic analysis of the plane frame structures with rectangular and I cross sections. A load incremental method combined with the tangent stiffness and the initial stiffness methods for each load increment is used for the solution of non-linear equations. Numerical examples are presented to investigate the behavior and the accuracy of the elasto-plastic non-linear application and the results of this study are compared with other solutions using the concept of plastic hinge.