著者

高橋 良和 日比 雅一 家村 浩和

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.8, pp.701-708, 2005-08-22 (Released:2010-06-04)

参考文献数

27

被引用文献数

2 7

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From the results of the past experiments, it is reported that the friction force and coefficient of frictional isolators are strongly dependent on the sliding velocity and pressure.In addition to them, the temperature is also the important factor for the property of materials.In this study, based on the tribology theory, a numerical model for frictional isolators, which consist of PTFE and SUS, is proposed. Compared with the experimental results of the shaking table tests, it is found that the model can simulate well the behavior of frictional isolators under variational normal pressure, sliding velocity and displacement.

著者

藤澤 和謙 桃木 昌平 山本 清仁 小林 晃 青山 成康

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.9, pp.385-394, 2006-08-25 (Released:2010-06-04)

参考文献数

8

被引用文献数

3 2

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Studied herein is theoretical mechanism of the failure of an embankment caused by overflowing from a reservoir. An experiment has been conducted to observe the phenomenon, and the theory of the mechanism has been developed on the basis of the erosion and the stability of the slope subjected to the erosion. Shallow water equation considering the slope angle has been used to describe the erosion, and Mohr-Coulomb failure criterion has been applied to the stability analysis. The results allow the surface profile and the erosional speed to be determined as functions of imposed parameters. At the end of this paper, we have discussed the scope of application, and examined the theory by an additional experiment.

著者

細田 尚 磯野 太俊

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.11, pp.825-834, 2008

被引用文献数

1 1

---

This paper describes the fundamental characteristics of vertical heat transfer due to thermal convection during the cooling period (September to February) in the northern part of Lake Biwa. The seasonal variations of the vertical water temperature and water quality distributions are firstly shown with the comparisons of calculated results by 1-D model and observed ones to explain the fundamental features of heat and mass transfer occurring in Lake Biwa through a year. Based on the examination of these results, it is pointed out that the thermal convection during the cooling period is the main mechanisms of DO transfer from the water surface to the bottom of lake. Then the mixing mechanism caused by thermal convection is investigated in detail numerically using 3-D CFD model. It is shown that thermal convection cells are observed in the computational domain, changing the positions of submerging portion temporally and promoting the mixing near the interface between the thermally stratified two layers. It is also pointed out that a fractal structure is observed in the flow generated by thermal convection.<BR>A stochastic model with Monte-Carlo simulation, which is similar to Ising model and forest gap model, is proposed to consider the results of numerical experiments. It is pointed out that the spatial flow structures can be simulated by the stochastic model qualitatively.

著者

鈴木 崇伸 堀 宗朗 古川 洋之

出版者

公益社団法人 土木学会

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

no.10, pp.631-638, 2007

被引用文献数

3

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This paper presents calculation method for displacement from acceleration record in easy way. Using recursive digital filter is good for easy calculation, so simple formula is proposed, which is combined of integration and low-cut filter. Shaking table test is carried out in order to investigate accuracy of calculated displacement The movement of the shaking table is measured by laser displacement meter, and two acceleration meters are installed on the table. Though data from laser meter include long period noise, calculated displacement is rather consistent with laser meter, after filtering noise. Proposed digital filter is useful for on-site health monitoring measurement.

著者

近藤 八重 水澤 富作

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.5, pp.83-91, 2002-08-28 (Released:2010-03-17)

参考文献数

18

被引用文献数

1

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This paper presents the impact response of simply supported rectangular Mindlin plates subjected to colliding of a steel ball by using the eigenfunction expansion method and the Hertz's law of contact. The effects of impact force, contact time and material properties on the mechanism of impact response generation and the characteristics of propagation of flexural waves have been investigated. It is seen that the initial impact response of steel plates and wooden plates subjected to colliding of a steel ball shows some different mechanism on the wave propagation. Beside the difference of mechanism of impact response generation, the sound pressure calculated by the present method on the assumption of plane wave shows good agreement of the acoustically experimental result.

著者

飛田 善雄 加茂 謙一

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.5, pp.295-306, 2002-08-28 (Released:2010-03-17)

参考文献数

17

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The incrementally nonlinear behaviors of engineering materials, in particular geomaterials, are often reported and formulated into constitutive models. We here discuss the mathematical structure of incrementally nonlinear constitutive models among stress rates, strain rates, and the rate of change in internal variables through the representation theorem of isotropic functions and their matrix forms. As the examples of incrementally nonlinear models we discuss the formulation of the multi-slip model and the modified elasto- plastic model leading to incremental nonlinearity. Both models are evaluated whether they can account for the behavior of sands during the rotation of principal stress axes and found to be satisfactory from a qualitative view point.

著者

金子 賢治 岸野 佑次

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.4, pp.385-396, 2001-08-29 (Released:2010-03-17)

参考文献数

23

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Observing numerical results obtained by Granular Element Method, we discuss the incremental stress-strain behavior of granular materials. We assume a periodic boundary for the numerical experiments to avoid disturbances caused by boundary controlling. Stress-probe tests starting with the intermediate data of a bi-axial compression test give a set of incremental stress-strain relationships. The result indicates that the flow direction for plastic loading is not constant as is assumed in the classical plasticity theory and depends on the direction of the stress increment. Comparing the numerical results with a proposed flow rule, we conclude that the origin of the direction dependency is the volumetric component of plastic strain.

著者

武 建勲 岸野 佑次 浅沼 秀雄

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.1, pp.497-506, 1998-08-26 (Released:2010-03-17)

参考文献数

9

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The authors have performed a set of numerical loading tests in terms of the Granular Element Method. The tests exhibit mechanical behaviors which are common among real behaviors of geological materials. These test results are very suggestive to know the internal mechanism hidden behind the macroscopic behaviors. This paper mainly concerns the plastic behavior whose mechanism has its main origin on the slipping between grains. A theoretical yielding condition, which explains the result obtained by the simulation, is derived from non-slipping condition for stable assemblies of rigid particles. Performing eigen-value analyses of the instantaneous stiffness matrix which is utilized in the Granular Element Method, the authors demonstrate the similarity of displacement fields accompanied by plastic deformations for different loading directions. This similarity explains why the common direction of plastic strain is assumed in the flow rule.

著者

牧野 淳一郎 川井 敦

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.2, pp.101-109, 1999-08-27 (Released:2010-03-17)

参考文献数

28

被引用文献数

1

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We overview the Fast Multipole Method (FMM) and the Barnes-Hut tree method. These algorithms evaluate mutual gravitational interaction between N particles in O (N) or O (N log N) times, respectively. We present basic algorithms as well as recent developments, such as Anderson's method of using Poisson's formula, the use of FFT, and other optimization techniques. We also summarize the current states of two algorithms. Though FMM with O (N) scaling is theoretically preferred over O (N log N) tree method, comparisons of existing implementations proved otherwize.

著者

竿本 英貴 松島 亘志 山田 恭央 羽田野 祐子

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.9, pp.649-657, 2006-08-25 (Released:2010-06-04)

参考文献数

19

被引用文献数

2 1

---

Recent ground pollution is a pressing problem and which has been widely studied in the field of geotechnical and geological engineerings. Although a porous media flow plays an important role from the aspect of ground pollution and it is governed advection-dispersion equation (ADE), however, the solution of ADE can not discribe the cardinality change observed in a field study. In order to circumstantially comprehend the essence of above fluid flow through the porous medium, a microscopic approach is employed. We constructed an accurate simulation model by means of image-based modeling technique with a series of high-resolution X-ray CT images of Toyoura sand acquired at SPring-8. Then, a series of porous media flow simulations using the SPH (Smoothed Particle Hydrodynamics) was performed to obtain the distribution of pore fluid velocity vectors and macroscopic permeability coefficient by averaging the velocity of SPH particles inside the model. The calculated macroscopic permeability coefficient conformed closely to the canonical value measured in a permeability test and the estimated velocity distribution was compared with some experimental result and discussed its properties.

著者

ペータ ステンベルク 椿 龍哉

出版者

Japan Society of Civil Engineers

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.6, pp.437-444, 2003

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The knowledge of material properties of solidifying concrete is of major importance during construction process when many subsequent damages can be prevented. In this paper an evolutionary material model which can be used during the whole period when solidifying concrete undergoes the transition from a liquid to a solid state is proposed. The evolution of the material parameters is governed by a function of water/cement ratio and elapsed time after mixing which corresponds to the degree of hydration of concrete. The model can be used for modeling uniaxial behavoir of solidifying concrete including creep. The parameters for the evolutionary function were determined from three experimental methods for uniaxial loading.

著者

岸 徳光 三上 浩 南波 宏介 BHATTI Abdul Qadir

出版者

土木学会

雑誌

応用力学論文集 (ISSN:13459139)

巻号頁・発行日

vol.8, pp.471-480, 2005-08

被引用文献数

2

---

In order to establish a simple and rational impact response analysis method for lightweight shear-failure type Reinforced Concrete (RC) beams with stirrup, three-dimensional elasto-plastic finite element analysis was conducted for total fourty-seven RC beams under falling-weight impacting. Here, tensile strength of concrete was assumed as 1/16th of compressive one. An applicability of the proposed analysis method was confirmed by comparing with the experimental results of fourteen beams. From this study, following results were obtained: 1) impact response waves and crack patterns can be rationally predicted by using proposed analysis method, and 2) ultimate shear capacity of the RC beams under impact loading can be rationally predicted by means of the proposed numerical analysis method considering a safety margin of 15 %.