Stresses and strains are induced in the built-up roof membranes by the joint movements in the substrates when temperature varies. In this paper, the behavior of built-up roof membranes due to a temperature decline were investigated introducing the visco-elasticity and temperature susceptibility of a roofing felt and a bonding asphalt construction built-up roof membranes. The membrane was replaced by the equivalent element model which consists of many tensile elements and shearing elements. Assuming superimpose principle, so that the relaxing stresses in the elements induced at some temperature were not affected by the later decline of temperature and kept the visco-elastic properties at that temperature, the moduli of elements were calculated based on the temperature, strain and stress histories. The stresses and strains in all elements were calculated step by step by the simulation method. The validity of this visco-elastic analysis method was discussed, comparing tensile loads observed in the experiment with the calculated ones. As an example of application, the behavior of bulit-up roof membranes due to an observed temperature decline were estimated.

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Surface free energy is one of fundamental properties of material. I wish to suggest a new method of measuring surface free energy of hardened cement paste. This repont aims at stating a fundamental conception and a theory of it.

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Improved stochastic model for concrete strength is proposed, in which the fracture process consists of stable crack accumulation step and unstable crack propagation step is taken into consideration. As the result of analytical study applying the improved model, it is found that the theoretical distribution of concrete strength of structural member can be expressed more exactly applying the logarithmic normal distribution than the Weibull distribution. after the fracture process of concrete is stabilized, and predicted concrete strengths in the structural members are in good agreement with previous experimental results.

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In this paper, we shall propose two analytical expressions of the frecuency- and amplitude-modulated oscillatory force applied to the structural frequency response testing. These are described as follows. First, the theoretical expressions of this force are defined by using the rotational angle φ(t) of the eccentric mass of vibrator (centrifugal agitator). Next, for unknown φ(t), the approximational expressions of this force are proposed by using the instantaneous circular frequency ω_i(t) of the eccentric mass of vibrator. And then, the difference between the theoretical and approximational expressions are presented. Furthermore, various numerical examples are illustrated to discuss these expressions. Consequently, we propose the theoretical and approximational expressions of this force in order to modify the forced vibration Run-down Test.

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It is necessary to estimate a probabilistic seismic safety of building structures to a non-white excitation, becase most of expected earthquake motions will have non-white spectral properties for the existence of the ground. In this paper a random response analysis method by Markov chain stochastic model has been extended to non-white excitation input and hysteretic MDOF system case and this extended stochastic model has been applied to a shear type 5-DOF bilinear system to amplitude-nonstationary non-white noise whose predominant period is shorter than that of a linear system corresponding to the hysteretic system. This theoretical method gives a nonstationary probability function P(S) of discretized response state S in force-deflection plane. The comparison between theoretical results and simulation ones based on Monte Carlo method has been made by a nonstationary probability function P(X) of response level X, which is equivalent to P(S). The theoretical results have showed relatively good agreements with simulation ones except for overestimation of the top floor (5th floor). It is expected that this stochastic method will be extended to inputs with longer period components or with frequency non-stationarity.

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The work done by the seismic load acting on a structure, namely the energy input, is an important quantity, which can be directly compared to the energy dissipation capacity of the structure. This paper presents a simple method to estimate the statistical parameters of the energy input from the stochastic model parameters of the ground acceleration. The method is based on a frequency-domain relationship between the energy input and the Fourier square amplitude spectrum of the ground acceleration, eq. (8). First the mean and the coefficient of variation formulas of the enrgy input to viscously damped linear single-degree-of -freedom system under classical stochastic models of earthquakes are obtained, as shown on Tables 1 and 2. The it is shown that the formulas are also applicable to elastic-plastic system with the availability of a simple equivalent-linearization technique. This provides a practical means to evaluate the reliability of a hysteretic structure, which has some limits on its energy dissipation capacity.

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The purpose of this paper is to investigate the solution of the problem subjected to a harmonic point load, which is tangential to the boundary surface, in the interior of an elastic stratum based on the rigid bedrock. Those which are operation processes to obtain the solution and examinations with reasonableness of the resulted solution are similar to our previous paper^<4)> showed the vertical problem. Reasonableness of the resulted solution is examined through two following cases. 1. Move the applied harmonic force from the interior position to the free surface of an elastic stratum, the solution is coincident with the solution in the different manner resulted from the problem subjected to the applied harmonic force at the original point on the free surface of an elastic stratum. 2. Let the stratum depth vary infinite, the solution is coincident with the solution resulted from the similar problem of an elastic half space. As this case of the tangentially applied force to the boundary surface of an elastic stratum isn't axially symmetrical problems, we must consider two surface waves which are well known Rayleigh and Love waves. The potential parts consist of these two kids of the functions containing singular poles. We must calculate complicated numerical integrations after catching positions of singular poles in Rayleigh and Love functions. As Rayleigh and Love waves are dispersive in the case of an elastic stratum having boundary conditions, we should take care of investigations of the resulted solutions.

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Embedded type column-to-footing connections are often used in order to connect steel columns with reinforced concrete footing beams rigidly. In this paper, the test results on the fracture mode and ultimate strength of this type of column-to footing connections are presented for the case of exterior columns where the amount of concrete encasement is limited. Based on these test results, the mechanism of stress transfer, the fracture mode, and the ultimate strength of footing beams due to the punching shear from steel column embedded are discussed. The fracture mode of the footing beam can be classified into two types by the directions of loading for the case of exterior columns, and the ultimate strength can be analyzed using the criterion for punching shear fracture of footing concrete. The test results on the ultimate strength of the embedded type column-to-footing connections reported hitherto can also be analyzed satisfactorily by using the stress transfer mechanism and the criterion for the punching shear fracture of footing concrete obtained in this paper.

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The purpose of this paper is to determine the critical values of fracture of defective structural members after crack propagation based on the COD in non-linear fracture mechanics. In order to evaluate the deformation capacity of defective structure members which fractuer after crack propagation in according with the COD criterion, the COD and the overall strain ε_∞ were measured using notched plate specimens. The relationship between COD and ε_∞ becomes almost linear after the specimens turn fully plastic. However, as the crack propagates, the increment of COD increases until the linear relationship disappears, The value of COD at this point is assumed as the critical value of crack propagation δ_c. It can be seen that the δ_c value for a particular type of steel is almost constant regardless of the size of specimens. Therefore, it is thought that δ_c is an effective critical value for fracture behavior of steel members.

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This paper describes an analytical method of evaluating flexural and shear deformations of flexural type reinforced concrete shear walls. When flexural reinforcing bars in the boundary column yield, cracks developed in the tension side column extend to the bottom part of the compression side column throught the infilled wall. As a result, both the shear and flexural deformations increase significantly. After these cracks take place, the hypothesis of a plane section remaining plane is no longer suitable, In this analysis, such a shear wall is represented as a truss system having a non-prismatic elasto-plastic truss member. The analytical rrsults are compared with results of the shear walls tested in the U.S.-Japan Cooperative Research Program. Following conclusions can be drawn from this study. 1. Shear deformation increases by the rotational mechanism having a rotation center at the base of the column under compression. 2. The ratio of the shear deformation to the flexural deformation is analytically determined by a truss model which has a non-prismatic elasto-plastic member.

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This report is to try to study the proper placement of the exit for escape within architecture, by conducting experiments of man's probing actions for exist by means of mazes, and measuring and analizing time required to find exits. As well as in the previous report (No.1), experiments were conducted by putting on view-obstructing hats to restrict the visibility range solely downwards, so as to simplify visibility conditions. As a result, the following were clarified; (1) The distribution of time required to find the exit showed exponential distribution; and the average time required to find the exit that was farthest from the starting point became longer in proportion to the exponent of the number of crossings between the starting point and the exit, which is expressed in formula (1). (2) In the case where the maze was ahead of the starting point, the tendency was observed that the exit which faced in the same direction as the advancing way from the starting point was easier to find, and the one which faced in the opposite direction was more difficult to find. (3) There was little significant difference in time required to find the exit btween the marked maze, which had differently-coloured papers respectively at the foot of each crossing and each dead end, and the unmarked maze, which had no papers.

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