Recent advances in computer technology have made it possible to solve numerous challenges but require faster hardware development. However, the size of the classical computer has reached its physical limit, and researchers' interest in quantum computers is growing, and it is being used in various engineering fields. However, research using quantum computing in structural engineering is very insufficient. Therefore, in this paper, the characteristics of qubits, the minimum unit of quantum information processing, were grafted with the crow search algorithm to propose QCSA (quantum crow search algorithm) and compare the convergence performance according to parameter changes. In addition, by performing the optimal design of the example truss structure, it was confirmed that quantum computing can be used in the architectural field.
This study examines the optimum shape of a trolley, the driving device of the retractable membrane roof. The closed-type trolley was determined as the model of the study, and a trolley composed of cylindrical-shaped inner and outer holders was selected as the basic model. Based on this model, a cylindrical-based optimal trolley model was proposed. In the basic trolley model, steel was used for the outer holder, and steel, titanium, and aluminum were used for the inner holder. In each case, the most economical shape for the external load of the basic model was newly proposed through the topology optimization process, and the finite element analysis results of the proposed model were compared to define the durability and economics. Here, topology optimization analysis and finite element analysis used the commercial software ANSYS. As a result of optimization, the volume of the outer holder of the trolley was reduced by 58.2% and the volume of the inner holder was reduced by 25.0% compared to the basic model. In the case of stress, a stress increase of 43.2 to 79.2% occurred depending on the material of the inner holder, but it was found to be significantly lower than the yield strength, thereby ensuring safety.
Building hardware joints are welded in most cases, which have risks of fire and explosion. Besides, the secondary damage of the destruction of the welded parts can be caused by the horizontal displacement of the structure due to earthquake or wind load. This paper compared the horizontal displacement following abilities of welded building hardware and non-welded building hardware. To do this, We conducted actual formation shake table test, and checked on the horizontal displacement following ability of structure by comparing their responses to earthquake load. We made the 2m-high framework to examine the responses of the actually constructed building hardwares, and analyzed the displacement responses of the welded-typed, non-welded-typed, and cruciform bracket building hardwares. We conducted the test by increasing acceleration rate until displacement reached 40mm corresponding to allowable relative story displacement II. The result of the test showed that the building hardware using welding work made cracking and breakage on welded connections of welded building hardware, but non-welded building hardware with no use of welding work and cruciform bracket building hardware make no problem, and that non-welded building hardware is superior to that of the welded building hardware in the horizontal displacement following ability due to earthquake or wind load.
Solar power is being spotlighted recently as a new energy source due to environmental problems and applications of solar power to curved structures are increasing. Solar panels installed on curved surfaces have different efficiencies depending on its position and the efficient positioning of solar panels plays a critical role in the design of solar power generation systems. In this study, the changing characteristics of solar irradiance were analyzed for hemispherical dome with a large curvature and the positioning of solar panels that can efficiently utilize solar energy was investigated. With an icosahedron-based hemispherical dome consisting of triangular elements as target model, a program for calculating solar irradiance using a normal vector of the solar module on each face was developed. Furthermore, the change of solar irradiance according to the sun’s path was analyzed by time and season, and its effects on shades were also examined. From the analysis results, the effective positioning could be determined on the basis of the efficiency of the solar panels installed on the dome surfaces on solar irradiance.
When attaching the building exterior, builder used welded-building hardware in general. But it caused variety accidents like fires and explosions. Thus in this study, we developed the building hardware that not use welding and can follow the structures horizontal displacement when an earthquake occurs in the load building. And shaking table test was conducted.
Shell structure that is best used for the long span structure is a structure which can effectively resist against the external load. But these structure has instability like snap-through and bifurcation buckling, and it has a characteristic sensitive to the initial conditions. Therefore, to determine the analysis model of DDOF Space Truss and when the beating load was applied in model, we confirmed the changing results for height and load.
Long span structures like space-structures have instability phenomenon, jump buckling or bifurcation. And these instability phenomenon responds very sensitivity, depend on the initial condition. In this study, define the 1-degree of freedom space structure and when model has beating load, analysis critical load of model using 3D contour map for load, variable , displacement in the axial. The analysis results, when is 1.0, is able to see the lowest critical load and the resonance phenomenon.
From the past, space structure have been widely used as sports arenas, religious facilities. And the demand and research for retractable structure is increasing recently. Therefore, we classify the retractable mechanism which is divided according to the retractable method of structures and survey the present condition of retractable structures built around the world.
The purpose of this study is to get analytic solution of space truss using homotopy perturbation. A homotopy perturbation was derived by formulating a governing equation for a space truss, and a semi analytical solution was obtained by homotopy perturbation. In conclusion, the analytical solution of the simple nonlinear model using the homotopy perturbation was compared with the numerical analysis result.
This study aims to apply homotopy method to space truss composed of discrete members to obtain a semi-analytical solution. For the purpose of this research, a nonlinear governing equation of the structures is formulated in consideration of geometrical nonlinearity, and homotopy equation is derived. The result of carring out dynamic analysis on a simple model is compared to a numerical method of 4th order Runge-Kutta method(RK4).
The purpose of this study is to investigate the applicability of multi-stage homotopy perturbation method to shallow arches in order to obtain a semi-analytical solution. For this research purpose, a nonlinear governing equation of the arches was formulated and a homotopy equation was derived using the formulated differential equation. The result of a dynamic analysis on a symmetric mode and an asymmetric one was compared with the classical homotopy perturbation method and the 4th order Runge-Kutta method.
This study aims to apply multistage homotopy perturbation method (MHPM) to SDOF space truss to obtain a semi-analytical solution. For the purpose, a nonlinear governing equation is derived in consideration of geometrical nonlinearity, and homotopy equation is formulated. The result of carrying out dynamic analysis on a simple model is compared to a numerical method of 4th order Runge-Kutta method (RK4), and the dynamic response by MHPM concurs with the numerical result.
This study analyze the buckling characteristics of trapezoidal and sinusoidal corrugation shapes with same weight. To do this, analyze the shear buckling characteristics through linear buckling analysis and on its theory.
The development of QEA(Quantum-inspired Evolution Algorithm) and their engineering-problem applications have emerged as one of the most interesting research topics. These algorithms find optimal values with the operators such as quantum-gate by using quantum-bit superposed basically by zero and one. In this process, the balance between the two features of exploration and exploitation can be kept easily. So, this paper is to propose an optimum design program for truss system based on QEA and 17 bar plane truss model is adopted as numerical example.
With the advent of quantum computer, the development of quantum-inspired search algorithms and their engineering-problem applications have emerged as one of the most interesting research topics. These algorithms find optimal values with the operators such as quantum-gate by using quantum-bit superposed basically by zero and one. In this process, the balance between the two features of exploration and exploitation can be kept easily. So, this paper is to propose an optimum design program for plane truss structures based on quantum-inspired evolution algorithm. The objective function consists of the weight of the structures, and the design variables are the cross-section areas. 10 bar plane truss model is adopted as numerical example.
본 실험은 우리나라 참깨의 단작, 맥후작별 vinyl mulching 재배하에서의 도복방지효과를 보고자 장려품종인 안산깨. 단백깨, 광산깨를 공시하여 개화초기에 75˚ 45˚ 의 인위도복 처리와 도복방지 처리로서 개화시에 지주를 세워 처리간의 효과를 조사했던 바, 그 결과를 요약하면 다음과 같다. 1. 개화초기에 75˚ 도복은 도복되지 않은 것에 비해 가장 감수정도가 커서 단작에서 75%, 맥후작에서 81% 감수되었다. 2. 개화초기의 무처리한 구에서는 단작직파에서 약간의 자연도복이 되어 18% 감수되었고 맥후작직파에서는 태풍피해로 75%의 큰 감수를 보였다. 3. 단작, 맥후작별 vinyl mulching 재배에서 개화초기에 지주를 세워 재배한 처리는 완전다수였다.