Large-scale Steel Structures Research Articles

レーザピーニングを大型構造物に適用するための基礎的検討

レーザピーニングを大型構造物に適用するための基礎的検討

Blasting Technology for Demolition of Large-Scale Steel Structure Buildings by Shaped Charge Cutter

It is a direction of blasting demolition for achieving the safe demolition of large-scale steel structures to use the technology of linear shaped charge cutter, which has been applied practically abroad[1], while is still at a initial stage in China. In this paper, the example of the blasting demolition of Shenyang Lvdao All-steel Structure Gymnasium is applied, which includes the technology of linear shaped charge cutter and electronic detonator initiating system and five 3-D protective measures. The result of this engineering is quite ideal in the end.

Research on Earthquake Load Analysis of Large Structures in Non-Slide Construction

Ocean large steel structures are usually constructed on the slide site, being prone to forming large deformation because of its features such as heavy weight, large bulk and great span. However, the 18 large-scale steel structures of a nickel ore project are need to building on the non-slide foundation, resulting in different settlements of foundation. Moreover, the earthquake load is one of main load of the high-level structure. And the earthquake often happens suddenly and is out of control, with devastating destructive power. To ensure the safety of construction, it’s necessary to analyze the influence of large steel structure responding to the seismic load. This paper expounds the analyzing method on the response of the large steel structure based on non-slide site to the earthquake load. This article has analyzed responses of three-dimensional finite element model to the earthquake load with ANSYS analysis of finite element, such as the stress, deformation analysis, modal analysis and transient dynamic analysis, and assessed the risk of earthquake. This paper provides a feasible and effective analyzed method for researching the response of structure built on non-slide site to the earthquake load, which has important significance for the seismic design of the structure.

Research on Schedule in Large-Scale Steel Structures' Construction Processing

Research on Schedule in Large-Scale Steel Structures' Construction Processing

ニューラルネットワークを用いた防撓パネルの変位及び応力の予測

At the design stage of the large-scale steel structure, displacement and stress are generally analyzed by using the FEM. At the initial design stage, it is required for evaluating conditions of numerous design candidates. Therefore, it is not efficient to use FEM with fine mesh for analyzing the strength of structures in spite of requiring accuracy in the evaluation. In this paper, Neural Network System is developed for predicting displacement and stress based on a coarse mesh with the same accuracy of fine mesh. It is able to predict accurate displacement and stress at stiffened plate using FEM analytical results with coarse mesh as input factors for Neural Network System. In order to improve the approximation accuracy of Neural Network System, Multiple linear regression method is introduced for selecting input factors for a Neural Network System. This technique improves the accuracy of Neural Network System and reduce manpower used for structure design. The proposed Neural Network System is able to predict displacement and stress in spite of changing the load, plate thickness, and the number of stiffeners.

NUMERICAL STUDY OF COLLAPSE BEHAVIOR OF STEEL BUILDINGS DUE TO EXTREMELY HIGH SEISMIC LOAD

This paper focuses on the methodology for modeling the dynamic behavior of steel structures due to severe earthquake ground motions. The development of the Improved Applied Element Method for analyzing the entire behavior of large-scale steel structures up to total failure is briefly discussed. The main features of the method are illustrated. The presented case-studies show different collapse mechanisms of moment-resistance steel frame structure under severe ground motions. The results show high capability on simulating the observed damage of many steel structures due to recent earthquakes.

High-Velocity Flame Spraying of Powder Aluminum Protective Coatings

Requirements to industrial processes for the thermal spraying of corrosion-resistant metal coatings on large-scale steel structures are formulated. The promise of high-velocity fuel·air flame spraying for this application is described. Regimes for the deposition of protective aluminum coatings by this process and their adherence characteristics were investigated. Metallographic studies including computer treatment of images of polished cross sections were carried out with the aid of the materials science software SIAMS.

Study on the framework for the design support system of large-scale steel structure using description of design process

This paper shows a framework that design process information is explicitly described and is implemented in the shipbuilding CIM system developing by authors. The two concepts are proposed as an elementary factor of design model in this framework. One concept is “Information of entity” and another one is “Information of attribute”. And design information processing is characterized as a progress from a rough design to detail design, so two design flows are proposed : one is “specification for model structure” and another is “specification for model status”. The specification for model structure means a structure of product model described by information models of entity and attribute. And a specification for model status means definitely description of information of relation and attribute values in the defined model and management that information.In the prototype system, the information processing functions driving the specification for model structure and the specification for model status are defined as system component, and a designer proceeds design activities using the components combining. As a result the process are described in components network and well managed.

Polish developments in ultimate limit states of steel framed structures

Abstract A forecast of Polish steel properties was given on the basis of the representative method of mathematical statistics. Some conceptions of low fatigue strength have been recently considered. Buckling resistance was evaluated from a probabilistic model and it has been specified for multiple buckling curves. Elastic-plastic instability of frames is analyzed as an effect of gravitational loads, wind and temperature actions and geometrical imperfections. Both rigid-plastic and perfectly elastic instability analyses are applied and a frame slenderness ratio is defined. Special topics of steel structures in fire temperatures and large-scale steel structures have been also developed.

Optimization for large-scale steel structures with discrete sections

An optimization method has been developed to find the minimum weight design of steel building structures which consist of discrete sections that are commercially available. In this study, emphasis is placed particularly on the practical applicability of optimization algorithm in engineering practice. The structure is optimized through element optimization under the element level constraints first, and if there is any violation of structural level constraints, it is adequately compensated by the constraint error correction vector obtained from the sensitivity analysis. A scaling procedure is introduced for the problems of large violated displacement constraints. The oscillation control in the objective function is also discussed. Dividing the available WF sections into two groups based on their sectional characteristics, improved relationships between section variables are obtained and used efficiently in the search for the optimum section in the section table. Numerical examples are included to demonstrate the usefulness of the proposed algorithm.