In this study, the vibration control performance of Tuned Liquid Damper(TLD) with nonlinear properties is investigate by a with shaking table test according to large excitation. Until recently, TLDs has been investigated by behavior of liquid using equivalent TMD analogy and liner wave theory. The properties of TLDs assumed immutable but became generally known as a matter of fact TLDs behavior has a nonlinear properties that change the TLDs characteristics according to excitation. It was measured base shear and wave height in water tank at 0.01g to 0.06g as 0.01g intercals and tuned 0.6Hz, 0.8Hz. The result of shaking table test showed trend decreased amplification ratio of base shear and wave height as more increased peak accelearation of vibration, what is more jump frequency that dependent excitation dimension.
In this study, numerical analysis of TMD to estimate optimal-design-parameter is investigated using actual excitation, and evaluated by comparing results of numerical analysis and optimal-design-parameter was devised by Soong. It assumed between 1~2 seconds the 1st mode natural period of an aged apartment which has 10~15 stories and then investigated optimal-design-parameter of actual excitation for evaluate optimal frequency ratio and damping ratio according to local site condition. At this time mass ratio was 1% and range of tuned frequency ratio was 0.8Hz to 1.2Hz at intervals of 0.01Hz, and optimal damping ratio was 1% to 14% at intervals of 0.002%. It estimated Optimal-design-parameter was evaluated by numerical analysis according to peak and RMS displacement, acceleration respectively local site. And the result of evaluated respond performance parameter respectively a period was shown low numerical-value than optimal-design-parameter was devised by Soong what is more peak acceleration indicated performance difference of 20% over
In recently, the method estimated construction's defeat using the infrared thermography was prefer to method of new repair and estimate as a good point that simple of application and save labor, what is more economic than other techniques and can reduce need time. The purpose of this study is to develope the technique to measure the corrosion of reinforcing bars using the infrared thermal photography graphic data. In this page, the former final purpose establishment that galvanic corrosion method of reinforced bars and infrared thermography system, and studied trend of thermography and photography graphic data by parameters of corrosion of specimens, atmosphere temperature, concrete cover depth etc.
This study is basic experiment for estimating influence of strength by curing temperature of concrete's heat of hydration and estimate relationship of compressivε strength development by initial curing temperature factor, and then asume temperature factor which influence compressive strength development and for showing basic document of quality control. According to the result of cement mortar by the curing temperature factor high-curing temperature shows high strength on 3 day compare with low curing-temperature, shows higher strength than the piece of high curing temperature.
Most concrete is recently made of an aggregate which is properly absorbed, and carried in it in order to do capability at every fields. We have been close to demand new capability of high flowing and enduring for specific concretes. That is difficult to cope with claiming the efficiency on deterioration from lack of a high quality aggregate. Therefore, For solving the problems we apply to a packing method for using dried materials. That is to say that it is a kind of making into an instant. In this study, There is a purpose to present fundamental data, comparing and analyzing a phenomenon of aggregate’s absorption following the rate of adding water, for using existing materials.
Numerous studies have suggested that the traditional project management tools do not adequately support the coordination efforts required to successfully deliver projects. because they were not developed to control uncertainty which is one of the characteristic of construction project. In traditional construction process control, supervisor usually measures the quantity of production for the project schedule. Flow production has suggested that better productivity, like that labor and cost performance can be achieved by reducing work flows variability. This research has suggested that 1) the circular concept of productivity with work flows variation. 2) the indicators that quantitatively measure work flows variation using productivity data which is obtained from the document of construction field. 3) measurement of productivity-based work flows variation for analyzing correlation with variation of productivity and verifies.
The present study is about a 3-dimensional design method based on prototype model using the parametric technique. Until now, architecture design using the computer has been limited to the 2-dimensional level. Although the outputs of some modeling programs appear 3-dimensional, they are basically the outcomes of 2-dimensional perspective drawings or presentations and, in the true sense, cannot be 3-dimensional methods using all variables related to three dimensions. To overcome the limitations and to apply the computer to design in a more useful way, machinery, automobile, aviation and shipbuilding industries have developed 3-dimensional tools based on concepts such as object-oriented modeling technique and parametric technique. However, few of such attempts have been made in the area of architecture. Thus, viewing that, among several methods tried in other industries, the 3-dimensional design technology based on the parametric technique may be usable in architecture design, the present study purposed to examine how to introduce and apply the concept to architecture design. With this purpose, finding the possibility of applying together the object-oriented modeling and the parametric modeling method, which are 3-dimensional modeling methods, and the design prototype method and the previous case based design method, which are design methods，we examined a 3-dimensional architecture design method under the title 'Prototype-based Design Method Using Parametric Technique’ and assessed its possibility by applying the method to real cases experimentally.
In this paper, simulating the wind induced responses of a building structure using a linear mass shaker is presented. The shaker force is calculated by using the inverse transfer function of a target structural response to the actuator. Filter and envelop function are used such that the error between wind and exciter induced responses is minimized by preventing the shaker from exciting unexpected modal response and initial transient response. The analyses results from a 76-story benchmark building problem in which wind load obtained by wind tunnel test is given, indicate that the linear mass shaker installed at a specific floor can approximately embody the structural responses induced by the wind load applied to each floor of the structure. The linear mass shaker signal is generated by the proposed method can be effectively used for evaluating the wind response characteristics of a practical building structure and for obtaining an accurate analytical model of the building under wind load.
Seismic control performance of MR dampers, which have severe nonlinearity, is different with respect to the dynamic characteristics of earthquake excitations such as magnitude and frequency contents. In this study, effects of excitation characteristics on the equivalent linear system represented by an equivalent damping ratio for single-degree-of-freedom (SDOF) systems with a MR damper are investigated through numerical analysis for various natural frequencies of the structures and design parameters of the MR damper. In addition, to implement the an equivalent linearization procedure considering non-stationarity and frequency contents of the earthquake excitation, seismic response reduction factors for artificial earthquake ground motions are proposed using regression analysis of the linear structural responses. Analysis results show that the relative magnitude of the excitation compared to the friction force of the MR damper and frequency contents of the excitation affect the equivalent damping ratio considerably, and appropriate combination of friction and damping produces additional damping effect
This paper presents vibration control of a real-scaled five-story steel structure subjected to horizontal excitation using a semi-active magneto-rheological (MR) damper. A large-sized double-rod MR damper, which is applicable for vibration control of the real-scaled five-story structure, is designed and manufactured on the basis of the field-dependent Bingham model of the MR fluid. The damping force of the MR damper is experimentally evaluated with respect to the excitation frequency at various magnetic fields. After formulating the governing equation of motion for the five-story structure associated with the MR damper, displacement and acceleration responses of the structure are discussed under pseudo earthquake excitation in which a hybrid mass damper is designed to reproduce seismically excited structural responses. The controllers which require only structural response of the damper installed floor for calculating the input current of the MR damper are designed to effectively suppress unwanted structural vibrations