An experimental study with regard to maturity and compressive strength development of concrete was carried out by using mortar and concrete specimens. Eight kinds of normal portland cement and two from Hokkaido district were used for motar and concrete respectively. On the basis of statistical calculation of this experimental data, the following observations and conclusions seem to be appropriate ; 1) The relation between logarithmic value of maturity and compressive strength development of martar and concrete expressed in cubic regression equation shows a good correlation. 2) Since the practical curves for compressive strength development below 210°D・D shown in JASS 5 were intended to give lower limit, the obtained curves based on this test results are higher in the range below 210°D・D, and the curves in the range above 210°D・D show lower value of concrete strength. 3) The standard additional temperature for calulation of maturity shows a little discrepancy by kinds of cement and water cement ratios, however it seems to be practically appropriate to take 10℃ hitherto as the standard additional temperature.

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This study describes the analytical results concerning the shear transfer carried by the shear resistant elements across the inclined cracks. The analytical method was FEM linear analysis used the models with some inclined cracks as many as the experimental results. The analytical results provided the information about the critical inclined crack near the ultimate shear strength.

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This research was performed to study the inelastic torsional behavior of steel members, eighteen specimens of which the cross-sections are the rolled H shape and the square hollow shape were tested with the experimental parameter of the slenderness ratio, the width-to-thickness ratio and the residual stress. For the rolled H-section steel member with the elastic end warping restraints, the analytical method based on the generalized hinge method was presented. The results obtained througth the experiments and the analyses may be summarized as follows For the H-section steel members, (1) The initial torsional stiffness depends on the end conditions. (2) As the slenderness ratio increases, the ductility factor decreases. (3) The inelastic torsional behavior can be conservatively estimated based on the generalized hinge method. For the square hollow section steel members, (4) The initial torsional stiffness is agreed with the analytical value. (5) The yield torque and the maximum torque are affected by the cold forming. (5) As the width-to-thickness increases, the ductility factor decreases. (7) The yielding behavior of section is affected by the residual stress due to cold forming.

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The purpose of these experiments is to give some data on the load-deflection curve for the base of the three-dimensional elasto-plastic analysis and to investigate the behavior of the steel space building frames. One story, one span and one bay small-sized steel space frames with the Joint Block type connections are tested under alternately repeated horizontal load. These frames are designed to fail by the column mechanism. The main variables are put on the eccentricity of space frames, the axial force ratio of column and the orientation of horizontal load. Based on the experimental results and these evaluation, several conclusions may be summarized as follows (1) The obvious plastic flow and the strain-hardening region are recognized at the virgin load-deflection curve. (2) Regardless of the eccentricity of space frames, the load-deflection hysteresis loops of space frames are stable and show the Masing's shape. (3) The elastic stiffness and the plastic collapse load of space frames are decreased by the existence of eccentricity. (4) Good agreement between the experimental and analytical results is found. (5) The Joint Block type connections are regarded as the rigid connections.

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This paper describes a method of analysing the collapse load of structures such as space frames combined with plates. This method can be mentioned as follows. Structures are discretized by means of finite elements. Triangular elements and beam elements are used for plates and frames respectively. Plastic behavior is restricted to element boundaries and piecewise linear yield conditions are adopted so as to solve the problem simply by yield line methed and linear programming. The discretized structural systems are calculated in repetition, the elements of which has been divided into two pieces as the needs of the case demand, in order to obtain as. much value of the collapse load of continua as possible. The necessity of redivision of elements is judged by solutions of LP problems on the partial structures composed of the element and the adjoining element, because the new boundary of the element will not rotate and extend alone. The solution of the present model can be given to calculate the solution tableau of the last model, which has been expanded and arranged to be suitable for the present model. Robinson's Rank Technique, also reports this paper, can be applied to the compatible equations for the sake of contraction of the LP tableau. This paper introduces an analysing process based upon the upper and lower bound theorem and reports some illustrative problems.

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Free-flight tests of flat plates and prisms were made in a wind tunnel to know the characteristics of dispersion of wind-borne missiles. In these tests, the models were released into a flow from rest and then caught by a net spread perpendicular to the flow. The positions on the net were recorded by a video camera. In this paper, probability distributions of the lift coefficient, which represents the magnitude of the aerodynamic force which disperses the models vertically, are calculated from the test results by using equations of motion of a two-dimensional model. The characteristics of the distributions and their relations with nondimensional parameters are discussed.

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In the previous paper the recording performance, that is, the observation capacity, of the conventional strong motion seismograph in Japan, typified by the SMAC accelerograph, was criticized introducing an algorithm by which analyzable range in terms of period and amplitude can be evaluated. As a result of this analysis, the recording accuracy of this instrument was found insufficient in the period range above 1 sec and below 0.1 sec mainly owing to that a conservative recorder with limited coverage of 40 db at most is installed. In this paper the ideal specifications to be equipped in a forth-coming strong motion seismograph are first explored in account of current demands from pure and engineering seismology, to say nothing of removing such fatal defect. Second, aiming at such specifications two different graded acceleration seismographs, the popular and the advanced, are manufactured. Popular type acceleration seismograph is essentially of a SMAC type accelerograph plus a digital recorder, though a small displacement-voltage transducer is attached to the SMAC pendulum. Three electric outputs and an absolute time code signal are led to the 4 channel-digital recorder which installs a 12 bit Analog-to-Digital converter, and 120 points/sec sampling unit. The dynamic range covered by this popular type instrument is 66 db. A high accurate crystal clock is installed as well. Delay line with 10 sec allowance is also equipped. Advanced type acceleration seismograph is composed of three servo accelerometers and a 4 channel digital recorder. The dynamic range adjustable by an introduction of Binary Gain Amplifier is from 78 db up to 114 db. Sampling rate is 200 points/sec and seismic signal at each point is digitized by 14 bits, plus 2 bits (floating). A microprocessor-controlled event detector and a delay line circuit with the allowance of 40 sec are also introduced. A qualified crystal clock is loaded as well. Several years of field tests have been giving us numbers of sophisticated seismic strong motion records by which advanced analyses are capable in wider amplitude-and-period range than that in the past.

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A new method for estimation of the statistical characteristics of geometric initial imperfections in rotational shells is proposed and applied to estimate the statistical properties of initial imperfections in hyperboloidal cooling tower shells. The method is based on the entropy maximum criteria, which are often used in information science for analysing random phenomena. From the present analysis, we have found that there exists a high possibility of causing geometric imperfections with relatively high harmonic numbers in the rotational direction. However, since there exist at present little available data for initial imperfections, the validity and applicability of results obtained in this paper for practical designs are still left unresolved. But in furure, if many measured imperfections in shell structures were assembled and analysed, it would be possible to correctly evaluate the estimated values and the method would have a possibility of application in practical designs.

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For grasping the diagonal compressive behaviour of reinforced concrete shear walls with faults, experimental and analytical programs were undertaken. Aoshear wall, a frame and fourteen walls with faults to protect severe failure of boundary columns were tested. One-fifth scale models of walls had faults made at the end of the panel. The variables selected for the test were (1) shape of fault, (2) arrangement of faults. Detail of specimens are shown in Table 1 and Fig.3. Diagonal compression force was applied by hydraulic test machine as shown in Fig.4. Fig.5 indicated hysteresis curves of the specimens in terms of the relationship between compression force and shear displacement of the wall. By having faults in panel, walls showed high capacity of displacement and no collapse was occured at the boundary columns. Calculated hysteresis curves are shown in Fig. 18 compared with test results. The failure mode were adequately identified and the maximum load were estimated with small errors. The displacement at the maximum load were considerably smaller by 50%.

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Most shear walls with steel reinforced concrete surrounding frames are designed in accordance with "the Standard of Reinforced Concrete Structures (RC) of A.I.J.", because few studies have been performed on shear walls with surrounding frame of steel reinforced concrete (SRC). In this study, to clarify the elastic-plastic behaviors of shear walls with SRC frames, shear walls with various surrounding frames were tested under alternating horizontal loads. The test program was composed of two series in which one is 6cm wall-thickness and the other is 10cm wall-thickness. Several types of fracture were observed even if wall-thickness is same, and the shear walls with SRC surrounding frame were ductile and strong rather than those with RC surrounding frame. It was recognized that the ultimate strength by the equation, which we proposed, agrees fairly good with the experimental results.

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