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Article type: Cover
1981 Volume 301 Pages
Cover1-
Published: March 30, 1981
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Article type: Cover
1981 Volume 301 Pages
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Published: March 30, 1981
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Article type: Index
1981 Volume 301 Pages
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Published: March 30, 1981
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Article type: Appendix
1981 Volume 301 Pages
App1-
Published: March 30, 1981
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HARUO TAKIZAWA
Article type: Article
1981 Volume 301 Pages
1-8
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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Three prominent types of frequency dependence exist in the impedance (complex modulus) characteristics exhibited by the constituent elements of a structure resting on unembedded foundation. Among these, Type A is featured by the marked tendency of frequency-independent loss modulus, and represents force-deformation response behaviour for a general class of closed systems. The others are typical in the energy-transmission mechanism between the open system of structure and the exterior medium of surrounding ground, Types B and C embodying respectively the swaying and rocking impedances of a surface footing bonded to elastic half space. While Type B turns out to be equivalent to the simplest Voigt model and yields no mathematical diffculty, Type C can be far more involved with the storage modulus and dashpot factor changing significantly in a certain sophisticated pattern according to the rate of loading. The second phase of this study examines the dynamics of the elements represented by these types of A, B and C. Restricting the selection of particular mathematical models within a group of rational impedance functions, the structural damping (constant Q) assumption is applied to the Type A impedance, and the formulations of swaying and rocking by A. S. Veletsos are used in modelling Types B and C. In addition, two combinations of (B+A) and (C+A) are taken up in these examinations, which correspond to the constant-Q viscoelastic media of soil. A set of general theories developed in Part I provides a guiding tool in clarifying the nonelementary beha-viour of Models A, C, (B+A) and (C+A); the current presentation, Part II, includes the simpler instances of A and C. Even though the dynamic properties derived are admittedly complicated and singular, their gross interpretation is also emphasized by introducing a certain equivalence with the elementary case of Voigt dynamic system.
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TSUNEYOSHI NAKAMURA, SHUICHI KAMAGATA, IKUO KOSAKA
Article type: Article
1981 Volume 301 Pages
9-15
Published: March 30, 1981
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The results (I), (II) below have been presented in this paper and the conclusions (III)〜(V) have been derived from these results : (I) The test result of a beam-column model specimen subjected to completely reversed cyclic plastic bending under varying axial compression has been presented. (II) A numerical analysis program has been developed by incorporating the constitutive equations of Part I and applied to the beam-column model of (I) and to beam specimens of Ref. [7] to predict the test results. (III) The very good accuracy of the analysis program of (II) has been verified with respect to the following three phases : (1) The complex lateral load-deflection relations of the beam-column model under varying axial compression have been predicted with a very good accuracy; (2) The lateral load-strain difference relations and the axial loadbending moment-curvature relations of the beam-column model have also been predicted with a remarkably good accuracy; (3) The predictions of the lateral load-deflection relations of beam specimens have also been of a far better accuracy compared to all the previous predictions. (IV) The present experimental and numerical results on the beam-column model demonstrate clearly the effect of varying axial compression on the lateral stiffness of a beam-column. Due to the loading condition such that the varying axial compression superposed on a constant axial compression is proportional to the midspan lateral force, the P⊿ moment due to a compression increment in the upward deflected state acts against the bending moment due to the downward lateral force increment, whereas the P⊿ moment due to a compression decrement in the downward deflected state is superpcsed on the bending moment due to the upward lateral force increment. Consequently, the lateral stiffness just after a deflection reversal under the former condition is considerably greater than that just after a deflection reversal under the latter condition, if compared at one and almost the same axial force level and displacement magnitude. (V) The numerical result on the beams has clarified the following new details : (1) The curvature distribution of a beam varies during the first 5th or 6th reversals as if the curvature peak propagated from the midspan toward the simple supports and the plastic regions are enlarged correspondingly; (2) The curvature and strain distributions and the corresponding deformation at the symmetric reversal point states are considerably different and not symmetric with respect to the undeformed axis; (3) The details of deformed states of a beam depend greatly upon the first direction in which the cyclic bending of the beam was started.
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Youichi MINAKAWA
Article type: Article
1981 Volume 301 Pages
17-27
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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TAKUJI KOBORI, TSUYOSHI TACHIKAWA
Article type: Article
1981 Volume 301 Pages
29-42
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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In this paper is considered a structure embeded in a perfectly elastic layer medium over a half-space when subjected to horizontal base rock motions. In order to avoid unnecessary complication, consideration is restricted to twodimensional rigid structure. In Sec.2 is derived the set of governing equations on soil-structure interaction system subjected to base rock excitation. In Sec.3 are determined the sway and the rotational spring constants of the base rock by using the values of statical ground compliance in the case of a half-space which have been derived in the former works. In Sec.4 are derived the analytical expressions for the sway and the rotational spring constants of sub-side soil ground when the basement wall vibrates horizontally or rotationally. It is verified by using Maxwell-Betti-Lamb's reciprocal theorem that the rotational spring constant under condition of the basement wall to be horizontally excited equals to the sway one rotationally. In Sec.5 are derived the analytical solutions of the dynamical wave pressure which operates on the basement wall when subjected to horizontal base rock motions.
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YASUNAGA FUKUCHI, YASUO DOI, KATSUHIRO KAMAE
Article type: Article
1981 Volume 301 Pages
43-51
Published: March 30, 1981
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In our country, most of shapes of holes in web plates of beams are circular and they are reinforced by sleeve pipes or double plates or others. Funahashi et al. reported that it was recognized experimentally that sleeve pipe reinforcing is little effective and the most effective method is double plate reinforcing. But sleeve pipe method is used most frequently in practice. The reason is considered that sleeve pipe method is more economial than double plate reinforcing, due to shortening of weld length, in spite of increase of volume of steel. But, the method to design beams with circular holes is not established yet and therefore it is desired that a design method is proposed. In America, the design method for beams with rectangular holes non-reinforced or reinforced by horizontal stiffeners is established. But, it is difficult to utilize it to design of beams with circular holes. In part-1, a method to analyze the strength of beams with non-reinforced circular holes was proposed. In this paper, the effect of sleeve pipe reinforcing is shown experimentally, and a method to analyze the strength of beams with sleeve pipe reinforced holes. Comparing the analyzed results to the experimental results, it is shown that the propos-ed method can predict appropriate values.
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MORIHISA FUJIMOTO, SHINJI MATSUSHITA
Article type: Article
1981 Volume 301 Pages
53-64
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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In steel frames, the fracture of welded parts must be prevented when the frames are subjected to large lateral displacement during the strong earthquakes. On this point of view, it is very important to clarify the magnitude of the strain in the beam flange near the connection under earthquakes. In this paper are investigated the relations between the ductility factor of the beam flange near the connection based on strain (e_b) and the ductility factor of the frame based on lateral displacement (μ), using the numerical method. As the result the simple and available e_b-μ equations are presented. The results are shown as follows. (1) e_b-μ relations can be estimated rationally by analyzing the two relations i. e. e_b-ξ_b relation and ξ_b-μ relation, where ξ_b is the ductility factor of the beam-end based on rotational angle. (2) e_b-μ relations under monotonically increasing lateral displacement are expressed in terms of the parameters on material (stress-strain) properties and of the ratio of the beam's bending component to the total lateral displacement in the elastic region. (3) e_b-μ relations under cyclic lateral displacement are much affected by the cyclic displacement history. Nevertheless, the following two values can be easily evaluated in engineering practice, using the monotonic e_b-μ relations. The one is the maximun value of e_b for the maximum ductility factor of the frame, and the other is the amplitude of e_b under cyclic lateral displacement with constant amplitude.
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MORIHISA FUJIMOTO, KOICHI ASAI, MAMORU KIMURA, KATSUHIKO SAITO
Article type: Article
1981 Volume 301 Pages
65-75
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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Cyclic loading tests of steel beam to composite steel reinforced concrete column connections were carried out. The beams, the connections and the columns of the test specimens were designed to an equal allowable strength. There were three different amount of the steel section in composite cross section. The inelastic hysteretic behavior and the shares of the steel in sustaining the internal force were compared among the three specimens and the following conclusions were obtained. (1) The internal force smoothly transmitted from steel beam to composite elements, even for the specimen with the steel-strength ratio of the beam to the composite elements of 30%. (2) The deformation in the element forming a plastic hinge had significant influence on the inelastic behavior of the entire system. (3) Therefore, there was no effect of other elements and the decrease of the steel sectional area had no direct effect upon the inelastic behabior of the entire system. From these results, it was found that the inelastic hysteretic behavior was sufficiently stable if the strength of the steel section of composite elements was at least 50% of the strength of the steel beam.
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ISAO MITANI, MINORU MAKINO, CHIAKI MATSUI
Article type: Article
1981 Volume 301 Pages
77-87
Published: March 30, 1981
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A theoretical analysis is performed on the post local buckling behavior of wide-flange beam-columns subjected to alternating horizontal load under constant vertical load. The method that was reported in previous paper (Part 1) is applied to the beam-columns subjected to alternating loading. The basic equation [Eq. (1)] is given by the principle of virtual velocities and principle of maximum specific power of dissipation. Analytical results based on the collapse mechanism shown in Fig.3 are compared with ones obtained in the previous paper [Ref.8)] and test results [Ref.6)]. Furthermore, corelation of the moment-rotation curves between under monotonic and alternating loading is investigated. The results may be summarised as follows, 1) The collapse mechanism curve based on the analysis shown in this paper is higher in strength than ones based on the analysis shown in the ref. 3). 2) The feature of the experimental moment-rotation curves are well predicted by the analysis. 3) Hysteretic loops of a beam-columns can be estimated from the curve obtained under monotonic loading.
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Hiroyuki NOGUCHI, Hideo SUGJYAMA
Article type: Article
1981 Volume 301 Pages
89-99
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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YUKAKA SEYA, GENGO MATSUI
Article type: Article
1981 Volume 301 Pages
101-107
Published: March 30, 1981
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KATSUHIKO ISHIDA
Article type: Article
1981 Volume 301 Pages
109-117
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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In order to qualitatively study the Fourier spectral characteristics of strong motion earthquake records on becrock, the Fourier spectra of 17 accelerograms (4.3≤M≤7.1), which were recorded in Japan, were analyzed. The result of this study suggests that the averaged acceleration Fourier amplitude spectra on bedrock level can be considered to be nearly flat statistically during the periods 0.1sec and T_m=10^<-0.39M-1.7>) sec. This qualitative result agrees well with the characteristics of theoretical spectra calculated by propagating fault model. The period Tm and the corner frequency frequency (Savage, 1972) [3] also agree well for magnitude M≥6.0. These results also indicate that the averaged Fourier spectra of accelerograms observed at a given site should be similar in shape to the transfer function of that site.
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TOSHIO SHIGA, AKENORI SHIBATA, JUNICHI SHIBUYA, JUNICHI TAKAHASHI
Article type: Article
1981 Volume 301 Pages
119-129
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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A 9-story steel frame reinforced concrete building which houses the architectural and civil engineering departments of Tohoku University has experienced several strong earthquake motions since its completion in 1969. Particularly, during the Miyagiken-oki earthquake of June 12, 1978, the measured response acceleration of the 9-th floor of the building was about 1000 gal which is the largest building response ever recorded. In this paper, described are 1) the damage to the building and the change of the natural period of the building due to the experience of strong earthquake motions and 2) the nonlinear response analyses of the building based on the inelastic properties of the constituent structural members during the strong ground motions. The results are summarized as follows. 1) The natural period of the building has become longer considerably as the building has been subjected to strong eathquake motions. The natural period of the building in the main part of shaking during the earthquake of June 12, 1978 was about twice as long as the initial natural period in small amplitude at its completion. 2) The calculated responses of the building subjected to the strong ground motions agreed well with the observed responses in the building. The calculated damage to structural members could interpret well the actual damage of the building in the event of the Miyagiken-oki earthquake of June 12, 1978.
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TATSUO OKA
Article type: Article
1981 Volume 301 Pages
131-137
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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Fluctuations of wind speed and ambient air temperature were measured in an urban and a rural area with a sonic anemometer and a fast response thermocouple in order to obtain sensible heat fluxes by the eddy correlation method. The results may be summarized as follows. (1) Heat storage in the roof is 25〜35% of the net radiation during the day and 50〜100% during night. (2) Roughness parameter in the urban area is 3.4m and 0.41m in the rural area. (3) Measured vertical eddy diffusivities (D_z) are approximately proportional to the wind speed except in case of windless convection. D_z is invariable in the vertical direction and D_z in the urban area is five times as large as in the rural area. (4) Comparing measured sensible heat fluxes at the lower observing sites with fluxes predicted by Tennekes' formula, a constant α_f in the formula is assumed to be 0.3. Sensible heat fluxes in constant flux layer (q_h) are in linear relation to the net radiation (R_n). Sensible heat fluxes in the urban area are usually upward flow and 60〜100W/m^2 larger compared with in the rural area. The rural fluxes are approximately proportional to the net radiation and qn/R_n ratios are 20〜25%.
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KOHSEI OKADA, MASANORI TSUJI, TAKAO MORITA, SEIICHI FUJIOKA
Article type: Article
1981 Volume 301 Pages
139-145
Published: March 30, 1981
Released on J-STAGE: August 22, 2017
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We collected the plans of assembly halls and auditoriums where social and cultural meetings nare held and various kinds of entertainments for citizens are given. Basing on the results of our investigations into the assembly halls and auditoriums in Osaka and Hyogo Prefecture, we classified the plan types of them. The conclusion are as follows; (1) Two types called the "single building type" and the "plural building type" are extracted from them. (2) The "single building type" is divided into the types called the "division interior type" and the "common lobby type". The "plural building type" is divided into two types called the "sepalated building type" and the "combined building type". (3) The "division interior type" amounts to 23.4%, the "common lobby type" 24.1%, the "separated building type" 17.1%, the "combined building type" 33.5%.
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KENJI MITSUYOSHI, SATOSHI HAGISHIMA, SEIJI SATO, TOSHIO ENDO, SHINGO O ...
Article type: Article
1981 Volume 301 Pages
147-155
Published: March 30, 1981
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In the preceding paper, PART I, we classified the residential districts into 8 types. In this paper, we carried questionnaires into execution in each type of residential districts. Then we analyzed the patterns of inhabitants' needs about living environment. And we discussed the relation between 8 types of districts and inhabitants' needs.
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