• Journal of Korean Association for Spatial Structures
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• v.16 no.2
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• pp.69-77
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• 2016

The purpose of this study is to present a method that can estimate the height of reaction facilities for large structural experiment through load flow as primary design procedure. The characteristic of the load transmission according to the type of experiment was analyzed to obtain tensile and compressive forces occurring on the reaction facilities. Strong walls that are affected by the bending moment is applied the post-tensioning method, and the strong floor under the control of the tension and compression is designed in accordance with the load flow. And the optimum cross-section of the reaction facilities was obtained by comparing the stresses of the tensile stress and crack the concrete. Through validating elastic analysis, the design results were satisfied a given design conditions.

• Structural Engineering and Mechanics
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• v.58 no.3
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• pp.597-612
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• 2016

This paper presents an optimization process using Harmony Search Algorithm for minimum weight of steel space frames under earthquake effects according to Turkish Earthquake Code (2007) specifications. The optimum designs are carried out by selecting suitable sections from a specified list including W profiles taken from American Institute of Steel Construction (AISC). The stress constraints obeying AISC-Load and Resistance Factor Design (LRFD) specifications, lateral displacement constraints and geometric constraints are considered in the optimum designs. A computer program is coded in MATLAB for the purpose to incorporate with SAP2000 OAPI (Open Application Programming Interface) to perform structural analysis of the frames under earthquake loads. Three different steel space frames are carried out for four different seismic earthquake zones defined in Turkish Earthquake Code (2007). Results obtained from the examples show the applicability and robustness of the method.

• Structural Engineering and Mechanics
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• v.47 no.4
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• pp.513-530
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• 2013

In this paper, an improved version of particle swarm optimization based optimum design algorithm (IPSO) is presented for the steel grillage systems. The optimum design problem is formulated considering the provisions of American Institute of Steel Construction concerning Load and Resistance Factor Design. The optimum design algorithm selects the appropriate W-sections for the beams of the grillage system such that the design constraints are satisfied and the grillage weight is the minimum. When an improved version of the technique is extended to be implemented, the related results and convergence performance prove to be better than the simple particle swarm optimization algorithm and some other metaheuristic optimization techniques. The efficiency of different inertia weight parameters of the proposed algorithm is also numerically investigated considering a number of numerical grillage system examples.

• Tribology and Lubricants
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• v.10 no.4
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• pp.33-42
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• 1994

An influence of inlet pressure on the performance of sector-shaped pad thrust bearings is investigated theoretically. The optimum conditions of film thickness or the optimum positions of pivot are found through the evaluation of load capacity for all available conditions of film thickness, under the operating conditions which the thermal and pad deformation effects can be neglected. The bearing performance including the inlet pressure effects is obtained for a wide operating ranges that inertia parameter(Re$^{*}$) is up to unity, and for the various cases of pad extent angle (number of pad) and the three cases of the angle between pads. The results show that the inlet pressure has a large influence on the performance of sector-shaped pad thrust bearings. In the design of sector-shaped pad bearings, due to the inlet pressure, the optimum number of pad is varied with the operating speed and the angle between pads, and the optimum position of pivot is located toward the leading edge along with the operating speed increases.

• Geomechanics and Engineering
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• v.1 no.3
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• pp.179-191
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• 2009

For a two-way drainage deposit under a surcharge load, it is possible to leave a layer adjacent to the bottom drainage boundary without prefabricated vertical drain (PVD) improvement and achieve approximately the same degree of consolidation as a fully penetrated case. This depth is designated as an optimum PVD installation depth. Further, for a two-way drainage deposit under vacuum pressure, if the PVDs are fully penetrated through the deposit, the vacuum pressure will leak through the bottom drainage boundary. In this case, the PVDs have to be partially penetrated, and there is an optimum installation depth. The equations for calculating these optimum installation depths are presented, and the usefulness of the equations is studied by using finite element analysis as well as laboratory model test results.

• Steel and Composite Structures
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• v.12 no.6
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• pp.505-522
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• 2012

An artificial bee colony (ABC) algorithm is developed for the optimum design of geometrically non-linear steel frames. The ABC is a new swarm intelligence method which simulates the intelligent foraging behaviour of honeybee swarm for solving the optimization problems. Minimum weight design of steel frames is aimed under the strength, displacement and size constraints. The geometric non-linearity of the frame members is taken into account in the optimum design algorithm. The performance of the ABC algorithm is tested on three steel frames taken from literature. The results obtained from the design examples demonstrate that the ABC algorithm could find better designs than other meta-heuristic optimization algorithms in shorter time.

• Journal of Auto-vehicle Safety Association
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• v.3 no.2
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• pp.5-10
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• 2011

Under the full frontal crash event, seatbelt system is the most typical and primary restraint device that prevents the second impact between an occupant and vehicle interior parts by limiting the forward motion of an occupant in the vehicle occupant packaging space. Today's restraint systems typically include the three-point seat belt with the pretensioner and the load limiter. A pretensioner preemptively tightens the seat belts removing any slack between a passenger and belt webbing which leads to early restraint of a passenger. After that a load limiter controls level of belt load by releasing the belt webbing to reduce occupant injurys. In this study, load characteristics of load limiters are optimized by the computer simulation with a MADYMO model for a frontal impact against the rigid wall at 56kph and then we suggest performance requirements. We derived optimum load characteristic from the results using four vehicle simulation models represented by the vehicle. Based on the results, we suggest the performance from the results of the second optimization using the simulation considering the design and the standardization. Finally, the performance requirements is verified by the sled tests including the load limiter device for the full vehicle condition.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.4
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• pp.94-101
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• 2010

Recently, the interest of precast concrete is increased for rapid construction in construction fields. Experimental study about the shear performance of the joint between hollow core slabs which have internal core to reduce their weight was performed. Main test variables were thickness of the topping concrete and existence of the wiremesh. Total 8 specimens including 4 in-plane shear and 4 out of plane shear were tested. Test results were analyzed in terms of cracking load, failure load, failure aspect, stiffness and ductility, and compared its design load to develop optimum design details. Test results indicated that the shear performance of the non-shrinkage mortar specimen was similar to that of 30mm thickness topping concrete specimen, and the effect of wiremesh reinforcement did not affect the failure load or stiffness of the specimens but the increase of ductility. And this paper presents the comparison results of the test results and design load to provide the optimum detail of the joint design between the hollow core slabs.

• Journal of Ocean Engineering and Technology
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• v.30 no.4
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• pp.294-302
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• 2016

Because of the importance of steel material saving and rational ship structural design due to the rapid increase in steel prices, a ship structural design system was developed for plate members reinforced by doubler plates subjected to biaxial in-plane compressive loads. This paper mainly emphasizes the design system improvement and upgrade according to the change in the in-plane loading condition of the doubler plate from the single load discussed in a previous paper to the biaxial in-plane compressive load discussed in this paper. A direct design process by a structural designer was added to this developed optimized system to increase the design efficiency and provide a way of directly inserting a designer's decisions into the design system process. As the second stage of preliminary steps of doubler design system development, design formulas subjected to these biaxial loads used in the doubler plate design system were suggested. Based on the introduction of influence coefficients $K_t_c$, $K_t_d$, $K_b_d$ and $K_a_d$ based on the variations in the doubler length, breadth, doubler thickness, and average corrosion thickness of the main plate reinforced by the doubler plate, respectively, the design formulas for the equivalent plate thickness of the main plate reinforced by the doubler plate were also developed, and a hybrid design system using these formulas was suggested for the doubler plate of a ship structure subjected to a biaxial in-plane compressive load. Using this developed design system for a main plate reinforced by a doubler plate was expected to result in a more rational reinforced doubler plate design considering the efficient reinforcement of ship plate members subjected to these biaxial loads. Additionally, a more detail structural analysis through local strength evaluations will be performed to verify the efficiency of the optimum structural design for a plate member reinforced by a doubler plate.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.135-142
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• 2011

Architectural market in the world is trying to develop Zero Carbon Buildng that doesn"t use fossil fuel. Residential building that thermal load such as heating and domestic hot water is over 70% in energy consumption is easy to make Zero Carbon Building compared with office building that is mainly electric load. So, As a preliminary for analyzing the effect of Solar thermal system in the building, an annual energy consumption of residential building and total heat loads are calculated. Based on this result, three alternatives of solar thermal system for hot water and heating are applied in the building while installation area is increasing. Solar thermal system is applied on balcony and roof of apartment building as the way to reduce thermal load. In the first case that solar thermal system for hot water is applied on the balcony, optimum installation area is $56m^2$. And you could install $40m^2$ of this system in the roof that angle is $30^{\circ}$. In the second case of solar thermal system for heating and hot water, you can install $40m^2$ on the roof. As a result of economic evaluation, the most economical application method is to install $40m^2$ of solar thermal system for only hot water on the roof of the building. At that time, you can payback the initial investing cost within 10 years. And carbon emission of this method can be reduced until about 4 ton per year.