APPLICABILITY OF A NEW SURFACE PREPARATION METHOD FOR STEEL STRUCTURE USING LASER

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Hiroshi Ogami ◽  
Katashi Fujii ◽  
Yukio Manabe ◽  
Kohei Ota ◽  
Asuo Yonekura
Keyword(s):  
Preparation Method ◽  
Surface Condition ◽  
Surface Preparation ◽  
Steel Structure ◽  
Steel Structures ◽  
Laser Cleaning ◽  
Coating Film ◽  
Test Results ◽  
Corrosion Prevention ◽  
Accelerated Corrosion

Surface preparation is very important in re-painting of steel structures so as to extend the effective term of corrosion prevention. Though grinding or blasting have been widely used to remove rust and old coating film on steel surface, both these methods have difficulty in completion of rust-removal and cause some problems such as dust scattering, noise, etc. In order to solve these problems, this paper presents the laser cleaning method which instantaneously sublimes/evaporates the rust on the surface of steel structure. The authors investigate the effects and the applicability of laser cleaning using the specimens made by accelerated corrosion method. The test results confirmed that the laser cleaning can remove the rust almost much as using sand blast, and the salt on the surface of steel can also be evaporated as good as the rust. Moreover, this method seems can be applied on wet surface condition because the moisture and water on the surface of steel can also be evaporated.

scholarly journals THE HEATING RATE IMPACT ON PARAMETERS CHARACTERISTIC OF STEEL BEHAVIOUR UNDER FIRE CONDITIONS

2006 ◽  
Vol 12 (4) ◽  
pp. 269-275 ◽  
Author(s):  
Zoja Bednarek ◽  
Renata Kamocka
Keyword(s):  
Heating Rate ◽  
Steel Structure ◽  
Steel Structures ◽  
Absolute Temperature ◽  
Strength Analysis ◽  
Test Results ◽  
Heating Rates ◽  
Linear Temperature ◽  
Strength Tests

The behaviour of steel structure components within a high temperature field depends not only on the absolute temperature, but also on the temperature vs time function and on the heating rate, dT/dτ. The research objective is the determination of the heating rate impact on selected strength parameters of structural steels. Tests were performed under conditions of a linear temperature increase with different heating rates and with a constant stress value, σ/fy . After strength tests, the samples were subjected to metallography. Test results proved that the heating rate makes a significant impact on parameters that determine the steel structure bearing capacity at higher temperatures and that the heating rate should be accounted for in the strength analysis of steel structures exposed to high temperatures.

scholarly journals Shock Wave Attenuation Characteristics of Aluminum Foam Sandwich Panels Subjected to Blast Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Jinglin Xu ◽  
Jianqing Liu ◽  
Wenbin Gu ◽  
Xin Liu ◽  
Tao Cao
Keyword(s):  
Shock Wave ◽  
Mild Steel ◽  
Polyvinylidene Fluoride ◽  
Sandwich Structure ◽  
Aluminum Foam ◽  
Wave Attenuation ◽  
Steel Structure ◽  
Steel Structures ◽  
Test Results ◽  
Attenuation Rate

Comparative experiments were conducted with two different structures to study the mechanism of aluminum foam sandwich attenuating blast shock wave. The sandwich structure is composed of “steel–aluminum foam–steel,” and the mild steel structure is composed of “steel–steel.” In the experiment, the polyvinylidene fluoride transducers were used to directly test the load of stress wave between different interfaces of sandwich and mild steel structures. The strain of back sheet was simultaneously measured using high-precision strain gauge. The accuracy of the test results was verified by Henrych’s formula. Experimental results show that the wave attenuation rate on the mild steel structure is only 11.3%, whereas the wave attenuation rate on the sandwich structure can exceed 90%. The interface effect is clearly a more crucial factor in the wave attenuation. The peak value of back sheet strain in the mild steel structure is much higher than the sandwich structure. The apparent overall “X” crushing band is produced in the aluminum foam core, and scanning electron microscope (SEM) observation clearly shows the collapse of the cell wall. Experiments on the sandwich structure with different aluminum foam densities indicate that increasing the relative density results in increased attenuation capability of the aluminum foam and decreased attenuation capability of the sandwich structure. Experiments on the sandwich structure with different aluminum foam thickness indicate that increasing the thickness results in increased attenuation capability of the aluminum foam and the sandwich structure.

Research and Simulation on Strengthening Steel Structure with Carbon Fiber Sheet

2012 ◽  
Vol 232 ◽  
pp. 82-85
Author(s):  
Yang Hou Chen
Keyword(s):  
Carbon Fiber ◽  
Concrete Structures ◽  
Steel Structure ◽  
Steel Structures ◽  
Test Results ◽  
Element Analysis ◽  
Cfrp Composite ◽  
Fiber Sheet ◽  
Strengthening Technique ◽  
Carbon Fiber Sheet

Carbon Fiber-Reinforced Polymer(CFRP) Composite Sheets Have Gained Popularity as a Viable Strengthening Technique for Fractured Concrete Structures. the Behavior of Carbon Fiber Sheet Materials to Cracked Steel Structures Is Quite Different from that of Concrete Structures. More and More Attention Are Paid to Research on Strengthening Steel Structure with Carbon Fiber Sheet. this Paper Presents the Study on the Steel Structure Bonded with Carbon Fiber Sheets. the Infinite Element Analysis Software ANSYS Is Used to Analyze the Effects of Strengthening a Steel Structure. and the Test Results of Crack Specimens Strengthened by Carbon Fiber Sheet Are Given. the Finite Element Results and Test Results Show that the Using of Carbon Fiber Sheet Can Improve Load Bearing of Structure and its Fatigue Life.

scholarly journals Effect of Steel-Cutting Technology on Fatigue Strength of Steel Structures: Tests and Analyses

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6097
Author(s):  
Sławomir Rowiński
Keyword(s):  
Fatigue Strength ◽  
Surface Condition ◽  
Steel Structures ◽  
Fatigue Tests ◽  
The Other ◽  
Plasma Cutting ◽  
Test Results ◽  
Water Jet Cutting ◽  
Roughness Measurements ◽  
Steel Cutting

This paper presents the results of comparative fatigue tests carried out on steel S355J2N specimens cut out using different cutting methods, i.e., plasma cutting, water jet cutting, and oxyacetylene cutting. All the specimens were subjected to cyclic loading from which appropriate S-N curves were obtained. Furthermore, face-of-cut hardness and roughness measurements were carried out to determine the effect of the cutting method on the fatigue strength of the tested steel. The fatigue strength results were compared with the standard S-N fatigue curves. The fatigue strength of the specimens cut out with oxyacetylene was found to be higher than that of the specimens cut out with plasma even though the surface roughness after cutting with plasma was smaller than in the case of the other cutting technology. This was due to the significant effect of material hardening in the heat-affected zones. The test results indicate that, in comparison with the effect of the cutting technology, the surface condition of the specimens has a relatively small effect on their fatigue strength.

Dynamic Characteristics of Base-Isolated Steel Frame under Seismic Ground Motion

2011 ◽  
Vol 255-260 ◽  
pp. 2341-2344
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Ali Jahanshahi
Keyword(s):  
Ground Motion ◽  
Base Isolation ◽  
Time History ◽  
Steel Structure ◽  
Steel Structures ◽  
Steel Frame ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Vector Method ◽  
Seismic Ground Motion

This paper presents the performance of base-isolated steel structures under the seismic load. The main goals of this study are to evaluate the effectiveness of base isolation systems for steel structures against earthquake loads; to verify the modal analysis of steel frame compared with the hand calculation results; and development of a simulating method for base-isolated structure’s responses. Two models were considered in this study, one a steel structure with base-isolated and the other without base-isolated system. The nonlinear time-history analysis of both structures under El Centro 1940 seismic ground motion was used based on finite element method through SAP2000. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as time-acceleration graphs for each story, period and frequency of both structures for the first three modes.

scholarly journals Experimental study on fatigue performance of Q420qD high-performance steel cross joint in complex environment

2021 ◽  
Author(s):  
Haigen Cheng ◽  
Cong Hu ◽  
Yong Jiang
Keyword(s):  
Fatigue Life ◽  
High Performance ◽  
Steel Structure ◽  
Steel Structures ◽  
Fatigue Tests ◽  
Fatigue Performance ◽  
Corrosive Media ◽  
Joint Connection ◽  
High Performance Steel ◽  
The Cross

AbstractThe steel structure under the action of alternating load for a long time is prone to fatigue failure and affects the safety of the engineering structure. For steel structures in complex environments such as corrosive media and fires, the remaining fatigue life is more difficult to predict theoretically. To this end, the article carried out fatigue tests on Q420qD high-performance steel cross joints under three different working conditions, established a 95% survival rate $$S{ - }N$$ S - N curves, and analyzed the effects of corrosive media and high fire temperatures on its fatigue performance. And refer to the current specifications to evaluate its fatigue performance. The results show that the fatigue performance of the cross joint connection is reduced under the influence of corrosive medium, and the fatigue performance of the cross joint connection is improved under the high temperature of fire. When the number of cycles is more than 200,000 times, the design curves of EN code, GBJ code, and GB code can better predict the fatigue life of cross joints without treatment, only corrosion treatment, and corrosion and fire treatment, and all have sufficient safety reserve.

scholarly journals A New Approach for Cylindrical Steel Structure Deformation Monitoring by Dense Point Clouds

2021 ◽  
Vol 13 (12) ◽  
pp. 2263
Author(s):  
Dongfeng Jia ◽  
Weiping Zhang ◽  
Yuhao Wang ◽  
Yanping Liu
Keyword(s):  
Steel Structure ◽  
Steel Structures ◽  
Point Clouds ◽  
Deformation Monitoring ◽  
Deformation Analysis ◽  
Relative Deformation ◽  
Structure Deformation ◽  
Single Time ◽  
Cylindrical Steel ◽  
Cylinder Fitting

As fundamental load-bearing parts, the cylindrical steel structures of transmission towers relate to the stability of the main structures in terms of topological relation and performance. Therefore, the periodic monitoring of a cylindrical steel structure is necessary to maintain the safety and stability of existing structures in energy transmission. Most studies on deformation analysis are still focused on the process of identifying discrepancies in the state of a structure by observing it at different times, yet relative deformation analysis based on the data acquired in single time has not been investigated effectively. In this study, the piecewise cylinder fitting method is presented to fit the point clouds collected at a single time to compute the relative inclination of a cylindrical steel structure. The standard deviation is adopted as a measure to evaluate the degree of structure deformation. Meanwhile, the inclination rate of each section is compared with the conventional method on the basis of the piecewise cylinder fitting parameters. The validity and accuracy of the algorithm are verified by real transmission tower point cloud data. Experimental results show that the piecewise cylinder fitting algorithm proposed in this research can meet the accuracy requirements of cylindrical steel structure deformation analysis and has high application value in the field of structure deformation monitoring.

scholarly journals Iron Oxide-Coupled Graphite/Fe–Si Steel Structure for Analog Computing from Recycling Principle

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 607
Author(s):  
Roberto Baca-Arroyo
Keyword(s):  
Raman Spectroscopy ◽  
Iron Oxide ◽  
Steel Structure ◽  
Oxide Thin Film ◽  
Coating Film ◽  
Analog Computing ◽  
Current Voltage ◽  
Graphite Structure ◽  
Graphite Lattice ◽  
Steel Foils

Analog computing from recycling principle for next circular economy scenario has been studied with an iron oxide-coupled graphite/Fe–Si steel structure which was built using recycled waste materials, such as lead pencil and 3% Si steel (Fe–Si steel) foils. Proximity phenomena, such as disordered structure of iron oxide and magnetostriction-induced conduction, inside graphite lattice resulted in functional properties to advance analog architectures. Thermal oxidation was the synthesis route to produce iron oxide as coating film on Fe–Si steel foil, whose structure properties were validated by Raman spectroscopy where phase formation of hematite, α-Fe2O3, resulted as iron oxide thin-film. Three graphite layers with different compositions were also analyzed by Raman spectroscopy and used for studying electrical conduction in Fe–Si steel/α-Fe2O3/graphite structure from current–voltage plots at room temperature.

A Framework to Support the Optimization of Modularized Oil and Gas Structures

2018 ◽  
Author(s):  
Vincenzo Castorani ◽  
Paolo Cicconi ◽  
Michele Germani ◽  
Sergio Bondi ◽  
Maria Grazia Marronaro ◽  
...  
Keyword(s):  
Lead Time ◽  
Oil And Gas ◽  
Steel Structure ◽  
Steel Structures ◽  
Modular System ◽  
Test Case ◽  
Plant Design ◽  
Conceptual Study ◽  
A Current ◽  
Gas Plants

Modularization is a current issue in the context of plant design. A modular system aims to reduce lead time and cost in design phases. An oil & gas plant consists of many Engineered-To-Order solutions to be submitted and approved during the negotiation phase. In this context, design tools and methods are necessary to support the design life cycle from the conceptual study to the detailed project. The paper proposes an approach to optimize the design of modularized oil & gas plants with a focus on the related steel structures. A test case shows the configuration workflow applied to a modular steel structure of about 400 tons. The modularized layout has been optimized using genetic algorithms. A Knowledge Base has been described to support the configuration phase related to the conceptual design. Design rules and metrics have been formalized from the analysis of past solutions.

Solar Concentrating Systems Using Small Mirror Arrays

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Joachim Göttsche ◽  
Bernhard Hoffschmidt ◽  
Stefan Schmitz ◽  
Markus Sauerborn ◽  
Reiner Buck ◽  
...  
Keyword(s):  
Power Plants ◽  
Raw Materials ◽  
Large Fraction ◽  
Steel Structure ◽  
Steel Structures ◽  
Cost Effective ◽  
Wind Loads ◽  
Drive Systems ◽  
Mirror Area ◽  
The Cost

The cost of solar tower power plants is dominated by the heliostat field making up roughly 50% of investment costs. Classical heliostat design is dominated by mirrors brought into position by steel structures and drives that guarantee high accuracies under wind loads and thermal stress situations. A large fraction of costs is caused by the stiffness requirements of the steel structure, typically resulting in ∼20 kg/m2 steel per mirror area. The typical cost figure of heliostats (figure mentioned by Solucar at Solar Paces Conference, Seville, 2006) is currently in the area of 150 €/m2 caused by the increasing price of the necessary raw materials. An interesting option to reduce costs lies in a heliostat design where all moving parts are protected from wind loads. In this way, drives and mechanical layout may be kept less robust, thereby reducing material input and costs. In order to keep the heliostat at an appropriate size, small mirrors (around 10×10 cm2) have to be used, which are placed in a box with a transparent cover. Innovative drive systems are developed in order to obtain a cost-effective design. A 0.5×0.5 m2 demonstration unit will be constructed. Tests of the unit are carried out with a high-precision artificial sun unit that imitates the sun’s path with an accuracy of less than 0.5 mrad and creates a beam of parallel light with a divergence of less than 4 mrad.

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