In city area, electromagnetic interference caused by buildings is a very important problem. For example, a well known ghost phenomenon is caused by interaction between incident and reflected waves caused due to the presence of large and tall buildings. In this study, absorption characteristics in VHF band of ferrite mortar, mixed with four different size of ferrite grain respectively, are measured by using parallel wire line method. Furthermore, absorption characteristics in VHF band of radio wave absorber, combined ferrite mortar with carbon fiber sheet, are measured, and it is considered whether thin radio wave absorber can be realized. As a result, as the size of ferrite grain is small, absorption characteristics in VHF band improve. And the improvement of absorption characteristics in VHF band is possible by combining fertile mortar with carbon fiber sheet.

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Studies on test methods of grading, specific surface, and amount of clay ratio of crushed stone fines as additives for concrete were carried out, and the on following three findings were obtained. 1. The sedimentation method(JIS A 1204) can be applied to evaluate the grading of crushed stone fines. 2. When the specific surface of crushed stone fines is evaluated by the blaine method(JIS R 5201), the applied confirmation is done beforehand. 3. The possibility that the clay content of crushed stone fines can be evaluated is high by the methylene blue adsorption amount method or the sand equivalent value method.

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This paper deals with the flexural and compressive strength properties of polymer-modified mortars with a garnet sand. Polymer-modified mortars with the garnet sand and three types of commercial polymer dispersions are prepared with various polymer-cement ratios and cement-sand ratios, and tested for flexural and compressive strengths. The polymer-modified mortars with a standard sand and a river sand are prepared, and tested for the same manner as the mortars with the garnet sand. It is concluded fom the test results that the water-cement ratio of the polymer-modified mortars at the same flow is markedly decreased by use of the garnet sand in place of the standard sand and river sand. The flexural and compressive strengths of the polymer-modified mortars with the garnet sand are larger than those with the standard sand and river sand. The flexural and compressive strengths of the polymer-modified mortars with the garnet sand tend to increase and decrease with increasing polymer-cement ratio, respectively.

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A mercury intrusion technique has been widely used to measure micro pores in porous materials. However, the information of shapes and locations of pores are not able to get through the measurement. A new technique for directly observing pores, in which gallium of liquid state is pressed into pores at higher temperature of its transformation temperature of 29.8℃ and then solidified by cooling down, was developed to measure them. The technique was applied to cement paste. The picture image of distribution of solidified gallium was observed through an electron probe micro analyzer (EPMA), and the shapes and locations of pores in cement paste were discussed.

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Ammonia gas generated from concrete causes discoloration of objects of art and also becomes a source of contamination of clean rooms which are parts of semiconductor manufacturing facilities. Measures for inhibiting generation of ammonia gas are therefore being called for. It was firstly verified in the study reported here that the ammonia gas generated from concrete originates from nitrogen compounds contained in cement and aggregate. A method of proportioning concrete materials for minimum generation of ammonia gas is proposed based in this finding.

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Fiber reinforced plastic(FRP) will be increasingly used as surface finishing and exterior materials which will be more required their durability. Nowadays, maintenance system is being evaluated as concerning with life cycle management. In this paper, the deterioration of FRP exposed outdoors and washed periodically was analyzed by referring degradation factors such as depositing dust, solar ultraviolet radiation and fungus. The frequency of maintenance and the effect of driving rain were quantitatively discussed based on multi-regression method.

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The purpose of this study is to present the evaluation method of touch on round handrails. First, sensory test concerning the touch was carried out using the various handrails and adults. As a result of sensory test, warmth, roughness, hardness and stickiness were extracted as factors which composed touch on handrails, then psychological scales of preference and sense of each factors were composed. Next, physical values of handrails which corresponded to psychological scales were measured by newly developed apparatuses. Finally, evaluation formulas were made by the complex of physical values, and the evaluation method of touch on handrails were presented.

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Expected value of time-history response can be formulated by assuming the phase differences spectrum in Fourier transform of earthquake waves as a normal probability curve. The effect of damping on the response spectrum can be obtained based on the formula. The ratio of maximum displacement to previous peak displacement during nonlinear response can also be calculated theoretically, which may be used for estimation. Both theoretical values were compared with those calculated from the responses to earthquake motions, from which a fair correlation was observed, especially in relation to the duration of earthquake motions.

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Evaluation of near-field ground motion is one of the most important issues in the seismic design of critical structures. In this paper, the damage data of the 1948 Fukui earthquake which is one of the disasterous in-land shallow earthquakes is compiled in order to estimate the ground motion intensity in near-field. The peak ground velocity is estimated from the damage data such as the overturning of tombstones and the displacement of structures. The results show that the peak ground velocities are over 120cm/s in the central part of the Fukui plane, about 100cm/s in Fukui city and more than 50 cm/s in the edge of the Fukui plane.

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Dynamic bifurcation analysis for the nonlinear Duffing's equation on a simple elastic structure is presented. This structure is a 2-bar elastic truss with dampers, and it has a geometrical nonlinear stiffness. It shows well-known bifurcation behavior on the homoclinic orbit caused by its geometrical nonlinearity, when it is assumed nondamping. In this paper, we show the forecast near the invariant saddle point of the homoclinic bifurcation on a 2-bar plane truss with damping system. It is possible to solve dynamic bifurcation in view of a geometrical nonlinear stiffness. We can readily find the focusing solutions based on the homoclinic theory.

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We have already proposed the analytical method of hysteresis system using the restoring force model of power function type (PFT-HYS) as the vibration response analytical method when the external force affects the nonlinear vibration system. In this paper, previous PFT-HYS method is improved to enhance the accuracy by the new analytical method. We investigated continuous vibration waveforms of vibration response acceleration and hysteresis loop by improving the hysteresis rule. We examined the validity and verification of the improved method by directly comparing experimental values obtained by the forced vibrations of the vibration system using laminated rubber with other analytical values.

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In estimating the motion characteristics of a building, the modal decomposition technique is frequently employed. However, it doesn't fit to the estimation of those of subsystems in a building structural system. This paper focuses on the damping estimation of such subsystems. By means of the transfer matrix method, a structure is divided into a number of substructures, which then are to be identified. A standing wave arisen inside a structure is decomposed into forward and backward moving waves in virtue of the wave propagation theory. Then, a local damping factor is estimated from the forward moving wave. This damping factor is regarding the local information, which the modal analysis cannot deal with. To demonstrate the validity of the proposed method, numerical simulations are conducted with respect to four-story building models subjected to random white noise excitations.

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This paper presents the optimum vibration control method of Active Mass Damper (AMD )to be constrained in its stroke limit. The method consists of the following three parts- ; the method to form the optimum filter avoiding the control spill-over with keeping in optimum control theory, the method to convert the characteristic of AC servo motor from its original velocity controlled type into a displacement controlled type by using the minor loop for AC servo motor, and the method the variable scalar gain at the last stage of the controller. From analytical result and experimental result of shaking table test, it was found that both results are substantially consistent, and the proposed control method is effective for constraining AMD stroke in its limit.

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This paper continues from the previous thesis (Part 1) of the same title. It compiles the twenty seven cases of deflection of earth retaining walls as observed in soft ground, and seeks inversely for the lateral load distribution to explain the observed modes at the successive stages from the first to final excavation. It was found out that the ratio of the depth of maximum lateral load to that of excavation bottom must be taken 2〜3 at the first stage of excavation. The ratio will decrease in association with the progress of excavation, reaching finally about 1.0 after the third stage.

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Today, it is necessary to make clear the ultimate shear strength of the PHC piles. In this research, we propose an estimation formula to predict the ultimate shear strength on the PHC piles. The estimation formula shows that the ultimate shear strength is the total of the share of the concrete(τ1), the share of the spiral reinforcement (τ2), the share of the axial force (τ3), and the share of the concrete filled in the hollow part of the piles (τ4). The estimation formula got for the conformability to be better than the experiment formula in the past.

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The present paper discusses the dynamic responses of a reticular dome which is installed hysteresis dampers between the dome and its substructure. The emphasis is put on the effects of the rigidity and mass distribution of the substructure, being deemed to give much influences on the response of the dome. The investigation based on the earthquake response analysis reveals the following four results. The first is that, along with the increment of rigidities and masses of the substructure, the response of the substructure grows with slight increase of dome response. The second is that the non -uniformness of the mass distribution within the substructure stimulates oval deformations to the substructure, followed by an increase of axial forces and bending moments of the ring girders of the substructure, but, within acceptable limit for design again by applying hysteresis dampers to the substructure itself. The third is that in spite of the large mass and large rigidity of the substructure and irrespective of the non - uniformness of mass distribution the dome response can be much reduced by means of the hysteresis dampers and the final result is that the present structural system can lead domes with such devices to be bearable against severe earthquake motions.

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The elastostatic analysis of stress concentration occurring around discontinuous (mixed) boundary of cylindrical shell roofs is performed. Firstly as approximate solution, theoretical plane stress and plate solution satisfying discontinuous boundary are derived with eigen function expansion or Muskhelishvili's method of Hirbert ploblem. Secondly FE analysis is performed. And Stress Resultant Intensity Factors (SRIF, like stress intensity factor in fracture mechanics) are calculated for various thickness or open angle models. Stresses around discontinuous boundary show singular behavior of 1/√r(r is distance from discontinuous point) which is same to one of crack problem. Smaller thickness increases In-Plane SRIF but decreases Bending SRIF. Larger open angle decreases Bending SRIF. Influence of open angle to In-Plane SRIF depends on the combination of boundary conditions.

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This paper deals with the ultimate shear strength of reinforced concrete columns composed of different strength concrete. In this paper, ultimate shear strength equations obtained from plastic analysis are proposed under the condition that the shear resistance is composed of the both truss mechanism and arch mechanism. Furthermore, from comparing with existing experimental results, it was verified that the ultimate shear strength of reinforced concrete columns composed of different strength concrete can be actually calculated by proposed equations.

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Recently, in seismic design, there is tendency to evaluate a building by the performance. One method of the evaluatoin is to estimate maximum response deformation for a building modeled by single degree system. In the previous paper, it was confirmed that EUV, which is defined by the intensity of energy input in stationary response, was almost equal to Actual Energy Input Velocity (ΔEmax/Te). Requisite Strength (Py) was calculated by solving the relationship, EIV=(ΔEmax/Te). In order to caIculate the Requisite Strength by this method, it is necessary to determine the Actual Energy Input Velocity (ΔEmax/Te), Total Input Energy (ED) and Plastic Deflection coefficient(d). In tihs paper, a method to determine ΔEmax/Te and d was proposed. ΔEmax/Te was estimated by elastic response analysis with 5% damping and d was estimated by maximum ductility and residual ductility. In case of ED, Akiyama's method, that is, ED was estimated by elastic response analysis with damping was used Elasto-plastic response analysis was carried out to investigate the accuracy of Requisite Strength calculated by the proposed model. As a result of the analysis, it was shown that the proposed model had generally enough accuracy.But for further improvement of the accuracy, it was important to estimate accurately the Plastic Deflection, particularly in the case of Hyogo earthquake which caused strong plastic deflection.

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The aim of this paper is to propose a simplified method of predicting the long-term deflection of reinforced concrete beams and one way slabs, due to decrease in rigidity caused by cracking, creep, shrinkage of concrete and slippage of tension steel at the fixed edge. The results of predicted deflections, using the simplified calculation method give 20 to 40 percent larger than that of AIJ RC Code and CEB Model Code 1990 because of additional estimation such as tension steel slippage. A comparison of experimental and calculated deflection shows fairly good agreement. It seems that farther studies are necessary on the effect of construction load for predicting the long-term deflection.

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Recently, several high-rise RC structures with open section core walls, typically H-shaped have been designed and constructed. The torsional stiffness of an open section core wall is smaller than that of a closed section one. However, little research has been carried out on the elasto-plastic torsional behavior of open section core walls. It is important to evaluate the structural capacities of a H-shaped core wall subject to lateral load (bending and shear) and torsional moment simultaneously. Therefore, loading tests and analyses for combined lateral load and torsion were carried out to meet this need. The main parameter of these tests is the ratio of torsional moment to bending moment at the lowest portion of the wall and the loading directions. The specimen with slabs subjected to a pure torsion was tested and investigated. Through tests and analyses, the following conclusions were obtained: (1) The resistant mechanism of a H-shaped wall subjected to simultaneous bending and torsion varies depending on the loading direction. (2) The slabs implove the torsional stiffness and strength of a H-shaped core wall. (3) The nonlinear finite element method can adequately simulate the hysteric behavior of the test specimens. (4) The correlation of lateral load and torsion is determined for each loading direction. The correlation curves at maximum strengths are very nearly elliptical for each direction. Therefore, the overall correlation is close to spherical. (5) The bending strength scarcely deteriorate while the ratio of torsional moment to the bending moment is not more than 25%.

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An analytical work was conducted on a prestressed concrete sub-frame assembled by post-tensioning. Layered element analysis considering bond-slip characteristics of prestressing tendon was used. The larger ratio of average effective prestress to compressive strength of concrete in the section and the smaller ratio of average effective prestress to 0.2% offset vield stress of the tendon were assigned, the larger difference of flexural strength between the cases with and without consideration of bond-slip was observed. Furthermore, the flexural behavior of the member was significantly influenced by the bond yield stress, while the effect of the bond stiffness was hardly found.

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To predict local behavior of ring-stiffened joints for tubular steel trussed towers, strength and deformation criteria are quantitatively derived from parametric experiments and FEM analyses. As results, #1 Criterion of yield strength is decided by considering local deformation, which is the modified fundamental strength, based on T-shaped section. This yield strength is also evaluated by 0.5%-offset method. #2 Ratio of the proposed yield strength to the ordinary fundamental strength is well correlated to ratio of the ring width outside a tubular steel to the diameter of a tubular steel. #3 Effect of axial force is considered as a reduction factor against the yield strength under no axial force.

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The purpose of this study is to propose and establish a formula that can apply on stress-strain relationships of metallic materials. In this study, multiple materials are widely selected, such as high strength steel, low yield point steel, stainless steel and aluminum alloy as well as mild steel. The result obtained from the proposed formula can reproduce the stress-strain relationships of metallic materials in a high accuracy. The shape factor obtained from monotonic stress-strain curve has a good correlation between material properties and the result using "prediction equation" also reproduce the stress-strain relationship in a high accuracy.

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In this paper, the maximum half-cycle energy input ratio is determined by extensive numerical response analysis. Maximum half-cycle energy input ratio is defined as the ratio of the maximum increment of the sum of elastic strain energy and plastic dissipated energy during a half-cycle of vibration to the maximum response of the sum of elastic strain energy and plastic dissipated energy. An expression is proposed to predict the maximum seismic response of bilinear systems based on the balance between input energy and absorbed energy during a half-cycle of vibration. The applicability of the proposed method is confirmed through comparisons with numerical results of bilinear systems.

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The purpose of this study is to clarify the influence of material properties, strain rate and the existence of stress concentration on low cycle fatigue characteristics, and to propose a simple estimating method of ε_l-N_f relationships by using material properties. The shapes of the test piece are smooth and notch. A linear ε_l-N_f relationship is obtained on smooth and notch pieces and it is independent upon material properties. A simple estimating method using yield strain, yield stress and semi-complementary energy which was obtained from the tensile test can be used to reproduce the per cycle hysteresis energy and the accumulated hysteresis energy.

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In order to evaluate the seismic force on the equipments mounted on floors of buildings subjected to very high levels of ground motions recorded during recent big earthquakes and to demonstrate the remarkable effects of utilization of base isolation to buildings to reduce the amplification of seismic response of the equipments, dynamic analyses were conducted using multi degree of freedom systems. The lateral seismic forces obtained from analyses are compared to the design values stipulated in Japan code (BCJ) and USA code (UBC). It is found that under the strong earthquakes the lateral forces of equipments several times exceed the maximum stipulated design forces. The use of isolation systems, in contrast, leads all the lateral forces to satisfy the stipulated design values.

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