著者

吉冨 信太 山川 誠 上谷 宏二

出版者

日本建築学会

雑誌

日本建築学会構造系論文集 (ISSN:13404202)

巻号頁・発行日

vol.69, no.586, pp.95-100, 2004

参考文献数

11

被引用文献数

2 11

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A method is proposed for selecting optimum discrete sections of steel frames using a two-step relaxation method. At the first step, the discrete optimization problem is approximately solved by using a continuous optimization problem wherein approximate expressions are applied to the standard sections. At the second step, the near optimal set of discrete sections is selected using the solution of the relaxation problem whose design space is limited to the neighborhood of the optimal solution obtained in the first step. Through the numerical example of a 6-story 5-bay plane frame under elastic constraints, it is demonstrated that a discrete solution can be obtained whose rate of increase in total steel volume from the continuous optimum design is only 1.8%. This approach is general enoueh to be applied to the problems under elastic-plastic constraints and those with any type of standard section lists.

著者

家倉 優人 荒木 慶一 上谷 宏二 吉田 亘利

出版者

一般社団法人日本建築学会

雑誌

日本建築学会近畿支部研究報告集. 構造系 (ISSN:13456660)

巻号頁・発行日

no.42, pp.105-108, 2002-05-24

著者

竹脇 出 土井 明裕 辻 聖晃 上谷 宏二

出版者

日本建築学会

雑誌

日本建築学会構造系論文集 (ISSN:13404202)

巻号頁・発行日

vol.68, no.571, pp.45-52, 2003

被引用文献数

1 3

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The soil resisting mechanism for piles is often represented by a static or dynamic Winkler-type spring. The present paper proposes two models for analysis and design of pile-supported building structures. The first-type model is a continuum model which deals with the governing differential equation directly and enables the, introduction of the one-dimensional wave propagation theory. The second-type model is a finite-element model enabling the introduction of the response spectrum method. The accuracy, of these models is clarified through the comparison in terms of transfer functions and time histories. The maximum seismic response of the models to the ground motion defined at the engineering bedrock surface as an acceleration response spectrum is evaluated by the response spectrum method in terms of complex modal quantities. The stiffness design for a specified maximum interstory drift and a pile stress ratio (maximum pile stress/allowable stress) is obtained by regarding the lowest natural circular frequency of the fixed-base model and the pile diameter as principal parameters.

著者

上谷 宏二 中村 恒善 森迫 清貴 石田 修三

出版者

一般社団法人日本建築学会

雑誌

日本建築学会構造系論文報告集 (ISSN:09108025)

巻号頁・発行日

no.445, pp.67-78, 1993-03-30

被引用文献数

7

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In the incremental analysis of the critical behavior of an elastic-plastic structure, a conventional iterative procedure for finding the set of element stiffness coefficients consistent with the material flow law may often lead to a pitfall of cyclic process, in which a multiple inconsistent sets of stiffness coefficients are to be alternately or recurrently selected. This is one of the most serious difficulties left unsolved in combined nonlinear analysis. In this paper, the intrinsic mechanism and characteristics of these cyclic processes are clarified for a simple rigid body-spring column model. On the basis of the results, an effective strategy for finding the consistent set is proposed with the use of the eigenvector associated with the smallest negative eigenvalue of system stiffness matrix.