Safety Analysis and Minimum-Weight Design of Rigid Frames Based on Reliability Concept

This paper deals with the safety analysis and the minimum-weight design of rigid frames based on reliability concepts. A safety analysis of redundant systems has difficult features, which are due to the fact that those systems generally have many various possible failure modes. As a rule, the approximations have been done on the assumptions of statistical independence and complete dependence among failure modes. However, the resulting solutions may be widely different as the number of failure modes increases. Also, usual structures have considerable dependence on their own failure mechanisms. A simple formula presenting a good upper bound is derived herein by using the correlations between every two modes. The discussion is done with respect to the lower bound. Its improvement is attempted by introducing a simple mathematical model, which is used for estimating the probability that any three events occur simultaneously. This paper also outlines the minimum-weight design with reliability constraints. The proposed method is employed in the safety analysis. The results are discussed and compared with those of the deterministic method. For large systems, an approximate design method is proposed, which decomposes the possible failure modes into basic and nonbasic modes

On Geometry of Truss

It has been shown, by a number of examples, that it is possible to obtain rational designs by introducing a geometrical variation of trussed structures into the design process. To determine the effective geometrical configuration, two kinds of parameters, cross sectional areas and nodal coordinates, need to be taken into account in the optimization procedure. The treatment of nodal coordinates apparently results in the increase of the number of design variables, which often induces some difficulties in the application of mathematical programming. Large scale optimization problems generally have a poor convergency to require excessive computation time or memory capacity. For such problems, U. Kirsch proposed a decomposition approach and showed its efficiency by some design examples. In this paper, a search for least-weight geometry is carried out by a two-step treatment based on Kirsch's approach. The cross sectional areas are assumed to be completely dependent on and determined from the set of nodal coordinates. Then, two design approaches are considered. The first approach is the deterministic method based on the allowable stress criterion. The other is the probabilistic method, where the safety is examined by the system failure probability. Also, the influence of buckling constraints and the number of employed nodes on geometry are discussed through some numerical examples

キョウリョウ ニ モチイラレル ホネグミ コウゾウブツ ノ キカガクテキ ケイジョウ オヨビ シンライセイ ニ カンスル キソテキ ケンキュウ

京都大学0048新制・論文博士工学博士乙第4336号論工博第1346号新制||工||496(附属図書館)UT51-57-E401(主査)教授 白石 成人, 教授 小林 昭一, 教授 山田 善一学位規則第5条第2項該当Kyoto UniversityDFA

An Application of Network-Topological Concepts to the Design of Framed Structures

In accordance with the increasing necessity of the rational design of structures, the optimum design method has been developed during the last two decades. The optimum design method eventually depends on two different bases by using digital computers. One refers to the mathematical programming, while the other refers to the structural analysis to be suitable for digital computations. There exist, however, many difficulties in their direct applications to the optimum design. Numerical results occasionally converge poorly and more calculation time is required as the number of design variables increases. Thus, a particular treatment which can decrease the number of design variables is necessary for the design of real large structures. In this paper, the authors propose the piecewise design, which is based on the concepts of Kron's Tearing and Interconnecting Method, in order to decrease the number of design variables. Also, the optimal geometric configuration, which has been scarcely considered in most studies, is discussed with the aid of the topological treatment

Structural Analysis and Design of Rigid Frames Based on Plastic Theorem

This paper is concerned with the plastic analysis and the design problems of multistory rigid frames by use of the linear programming technique. The objective of this work is to develop the plastic analysis and design of rigid frames, paying attention to the graph theory, and to reduce the computer core size and also to save the execution time by using a decomposition technique. A few examples are presented to illustrate the method proposed here

New BPS Solitons in 2+1 Dimensional Noncommutative CP^1 Model

Investigating the solitons in the non-commutative $CP^{1}$ model, we have found a new set of BPS solitons which does not have counterparts in the commutative model.Comment: 8 pages, LaTeX2e, references added, improvements to discussions, Version to be published in JHE

Resilient Restoration Scheduling on Road Network

The purpose of this study is to enhance the resilience of restoration scheduling for road networks. Optimal scheduling for resource allocation plays an important role on early restoration. However, circumstances in the post-seismic period are more likely to change due to various factors such as secondary disaster. Furthermore, it is necessary to prepare for unexpected damages. This study examines a method to reduce changes of restoration plan with keeping the adaptability against uncertainties in the post-seismic period. Specifically, an attempt is made to clarify factors strongly related to the delay of restoration in the flexible scheduling which is based on allocation priorities of restoration groups proposed by the existing studies. In this study, numerical simulations are presented to investigate the influence of the change of schedule on early restoration. And then, this paper discussed a method to keep initial restoration plan and to enhance adaptability to circumstances changes

A research about the automatic construction of Web/3D model house from 2D digital pictures

In recent years, the survey is performed for repair, such as a bridge and a building built in past, spending great expense. And it is anxious for the survey technique that doesn’t need cost and time more. Then, we made an idea of the technique of precise 3D model creation by 2D pictures. However, the technique of performing the improvement in accuracy of convergent photographing and automatic acquisition of corresponding points was not established. Therefore, in this research, we try to obtain a semi-automation of corresponding points acquisition from initial corresponding points and the improvement in accuracy of convergent photographing. Moreover, we applied the research to the used house of Japanese real estate, and the applicable field was selected as the high needs of the residence of 3D model. And we developed the system that everyone could create Web / 3D model house by VRML easily without requiring expensive apparatuses or expertise

Development of a System for Making Guide Maps based on the Idea of the Cognitive Map

Digital maps are very easily applied as route guide maps. Route guide maps are provided through Web or a mobile phone services, and demand for such services is increasing. However, the production of a route guide map requires a great deal of time. Therefore, it is difficult for general users to make route guide maps. The purpose of the present research is the development of a system that can generate a route guide map using the Digital Map 2500 (Spatial Data Framework) published by the Geographical Survey Institute. This system will not require advanced equipment or expert knowledge. Therefore, anyone can produce route guide maps easily and quickly. By using the Digital Map 2500, the time and cost required in order to generate a map are reduced. Moreover, a useful route guide map can be created by simplifying the map form based on the human cognitive map