著者

林 盛 山﨑 康造 木村 俊明 権藤 智之

出版者

一般社団法人 日本建築学会

雑誌

日本建築学会技術報告集 (ISSN:13419463)

巻号頁・発行日

vol.25, no.60, pp.935-940, 2019-06-20 (Released:2019-06-20)

参考文献数

7

被引用文献数

1 5

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This paper reports the design and construction process of 3D curved reinforced concrete roof in a recent project. In design process, “base model” based on NURBS was used to make consensus on the shape between designers and contractors. In construction, it was utilized for high precision construction and rationalization.

著者

木村 俊明

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.86, no.790, pp.1655-1663, 2021-12-01 (Released:2021-12-01)

参考文献数

24

被引用文献数

1

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Since there is a close relationship between the form and force in the large span spatial structures, it needs to design a suitable structural form corresponding to the stress transmission. Furthermore, it is desired to construct efficiently with saving resources for reducing environmental loading. Structural engineers need to judge totally by considering various requirements (e.g. structural safety, aesthetics, constructability, and economics) for a short time. A structural rational form can be found easily using the optimization method. There are various studies of computational form-finding methods for large-span spatial structures. Recently, it has been applied for the realization of practical design. Generally, optimal shape tends to be a complex shape. According to the construction reports of its application, it can be confirmed that issues about constructability of complex shapes and reducing scaffolding material have been solved in the construction phase. It is significant to solve the construction problems during the early design phase by using optimization methods. Removing supports is one of the important construction processes for spatial structures. Generally, it is mentioned that depending on the support conditions during the removal process, the internal stress may be higher than those in the completed state in the RC large-span structures. From a point of view of safety, it is necessary to plan to remove supports carefully. Furthermore, planning for the construction process depends largely on the experience of the contractors/designers. In the case of complex shapes, it can be imagined that it involves a lot of trial and error and is extremely difficult. If the construction plan can be reasonably designed at the stage of the form-finding process, it will be possible to realize further resource-saving and efficiency of construction materials. There are a lot of studies about optimization for removing supports in the construction process of the truss or tensile structures. However, to the author's knowledge, there are a few studies for RC spatial structures. This paper presents a simultaneous optimization method for the large span spatial structures obtaining the process of removing supports in the construction and the shape of the completed state. An optimization problem is formulated to minimize the summation of the strain energy during removing supports. The optimization algorithm consists of two methods. The coordinates of B-spline control points are optimized using Sequential Quadratic Programming (SQP). Furthermore, Local Search (LS) is used for obtaining the order of removing supports. It is shown in the numerical examples that not only obtaining strain energy minimized shape, react force and stress are suppressed during the process of removing through optimization. In the case of a 2D arch, the optimal order is to start from the end with removing the center at last. In the removal phase, it is effective to leave the center support during the removal to reduce bending deformation. By using this method, it can realize the construction plan for the supports considering both structural safety and constructive efficiency. Moreover, the proposed methods require less computational cost than the heuristic method shown in the numerical example. In the optimization using NP2, it is possible to obtain the solution with less computational cost than using NP1. However, the order of removal of supports becomes complicated. From a point of view of practical design, this result needs caution to avoid mistakes in construction.

著者

野田 賢 木村 俊明

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.87, no.793, pp.285-294, 2022-03-01 (Released:2022-03-01)

参考文献数

22

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This paper presents an optimization method of the joint arrangement for shell structures composed of CLT panels. The joining system is modeled as link elements with multidirectional stiffness. Their stiffnesses are calculated by multiplying the weight parameters defined as the design variables to the original stiffnesses. Furthermore, the joint arrangement is controlled by multiplying a power-law function to design variables. An optimization problem is formulated to minimize the strain energy. The effectiveness of the proposed method is shown through numerical examples. It is confirmed that the joint arrangement in each direction is optimized corresponding to the stress state.

著者

薄木 理一郎 木村 俊明 金田 尚志

出版者

Japanese Society for Food Science and Technology

雑誌

日本食品工業学会誌 (ISSN:00290394)

巻号頁・発行日

vol.25, no.6, pp.338-341, 1978

被引用文献数

3

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シリコ-ン油(SO)の示すフライ油劣化防止効果の作用機構を知る目的でSOを大豆油に添加,添加濃度,重合度(粘度),加熱油の性状について検討し,つぎの結果を得た。<BR>(1) 180℃での通気加熱,およびじゃがいもフライ時とも,添加濃度は10ppmが適当と思われた。<BR>(2) 20, 200, 1000, 12500センチストークス(c/s)の4種のSO中,20および200c/sの両者により大きな効果を認めた。<BR>(3) 加熱油およびフライ油をケイ酸カラムクロマトで分画し,その特数を各々の無添加油の分画区分と比較したところ,各区分とも酸化の遅延を表わす特数値を示していたが,特にSO添加による顕著な変化は認めがたかった。これまでいわれているSOの種々の作用が各々に働き,全体として熱酸化を抑えているように思われた。