The Deformation Analysis and Control of Large Steel Structures Based on Non-Slide Construction Site

2011 ◽  
Vol 255-260 ◽  
pp. 649-653
Author(s):  
Yan Guo ◽  
Qing Zhang ◽  
Xiang Qiang Bai ◽  
Shen Hong Pan

The layered construction technique is the common method of large steel structures in the non-slide construction. In process of the former three-tier construction, the structure is prone to forming large deformation because of great span, large weight of interlayer equipments and other various factors. In this article, to obtain high dimensional accuracy and good deformation control data, the positions of temporary support points of the 3M201 that is a module of large steel structure in a project are optimized successfully with the ANSYS optimization of finite element.

2012 ◽  
Vol 157-158 ◽  
pp. 1632-1635
Author(s):  
Gong Sheng Yang

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.


2021 ◽  
Vol 13 (12) ◽  
pp. 2263
Author(s):  
Dongfeng Jia ◽  
Weiping Zhang ◽  
Yuhao Wang ◽  
Yanping Liu

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.


2013 ◽  
Vol 444-445 ◽  
pp. 971-975
Author(s):  
Zhan Sheng Liu ◽  
Xiao Feng Wu ◽  
Rui Long Xu

Prestressed steel structure is the common form of space structure. BIM technology is used to every field of the construction industry. In order to apply BIM technology to the design and construction of prestressed steel structures, Xuzhou stadium prestressed structure was took as an example with BIM technology. Firstly, development standards of the family are created. Secondly, three-dimensional positioning technology and then establishing three-dimensional models of BIM are designed. Finally, the construction process of Xuzhou stadium is dynamically simulated.


2012 ◽  
Vol 155-156 ◽  
pp. 1061-1065
Author(s):  
Gang Wang ◽  
Li Na Feng ◽  
Xiao Ming Zhang

Basing on the original mechanical structure of arc-submerging welder for flat fillet seams, this article designs an arc-submerging welder control system for large steel structures flat fillet seams, such as blast furnaces, oil tanks, and so on, and expatiates on the working principle by circuit designing and testing in detail. This control system has been used greatly in DongYing, DaGang and other construction site for large steel structure.


2021 ◽  
Vol 40 (3) ◽  
Author(s):  
Paul Dario Toasa Caiza ◽  
Rüdiger Schwendemann ◽  
Paola Calero ◽  
Thomas Ummenhofer

AbstractThe demand of non-destructive methods to detect cracks caused by fatigue or brittle behavior in large steel structures has increased in the last years. Thermography based on electromagnetic induction is a promising method to detect cracks in weld seams and notches. This paper presents a portable experimental setup, which allows to perform in situ crack detection tests on large steel structures. The success of this configuration is based on the use of a highly efficient switched H-Bridge circuit, which can generate a square-wave output voltage with a fundamental frequency up to 100 kHz. Due to the low losses and the low necessary DC-link voltage, the circuit can be supplied by a lithium-ion battery, which allows a small and light setup. The generated square-wave output voltage supplies an air coil resulting in a high frequent triangle current. The induced electromagnetic field caused by the current signal generates eddy currents in the steel structure. Due to an increased current density of the eddy currents in the crack area, there is a measurable temperature increase near the crack. The resulting temperature field is visualized and recorded with an infrared (IR) camera, which shows in real time the occurrence of cracks.


Author(s):  
Lačezar Ličev ◽  
Jakub Hendrych ◽  
Jan Tomeček ◽  
Radim Čajka ◽  
Martin Krejsa

Reliability and security of a power transmission depends on the state of the power grid and mainly on the state of the Extra-High Voltage pylons. The paper deals with deformation analysis of existing steel structure of selected Extra-High Voltage pylons which showed excessive differences comparing to the original design. In the assessment of the situation, geodetic survey of selected pylons of power grid that showed the greatest deformation was performed. On taken images, deformation of steel structures by using the FOTOMNG system was also analyzed. The proposed method allows a modeling of the structure of the object based on precisely obtained photographic documentation of the current state. It also represents a very effective method which allows to quickly and efficiently analyze the deformation in the structure of Extra-High Voltage pylons in the critical position of the power grid. Other benefits include the possibility of repeatable and safe measurement.


2018 ◽  
Vol 28 (1) ◽  
pp. 137-141
Author(s):  
Petya Yordanova – Dinova

This paper explores the comparative analysis of the financial controlling, who is a result from the common controlling concept and the financial management. In the specialized literature, financial controlling is seen as an innovative approach to financial management. It is often presented as the most promising instrument of financial diagnostics. Generally speaking, financial controlling is seen as a process of managing the company`s assets which are valued in monetary measures. The difference between the financial management and the financial controlling is that the second covers all functions of management, analysis and control of finances, aiming at maximizing their effective use and increasing the value of the enterprise. Financial controlling is often seen as a function of the common practice of financial management. Its objective is to preserve the financial stability and financial sustainability of enterprises operating in a highly aggressive business environment.


2011 ◽  
Vol 255-260 ◽  
pp. 2341-2344
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Ali Jahanshahi

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.


2020 ◽  
pp. 120347542098255
Author(s):  
Kayadri Ratnarajah ◽  
Michelle Le ◽  
Anastasiya Muntyanu ◽  
Steve Mathieu ◽  
Simon Nigen ◽  
...  

Dupilumab, a monoclonal antibody against the common receptor of interleukin (IL)-4 and IL-13, was the first biologic therapy approved in Canada for treatment of moderate-to-severe atopic dermatitis (AD). While it is considered safe and effective, dupilumab is not universally effective and 8%-38% of patients develop conjunctivitis, while some patients develop head and neck dermatitis. Thus, new therapeutic options are warranted. While both IL-4 and IL-13 play important roles in the pathogenesis of AD, it has been recently demonstrated that IL-13 is the primary upregulated cytokine in AD skin biopsy samples. A placebo-controlled phase 2b clinical trial evaluating the efficacy and safety of lebrikizumab, an IL-13 inhibitor, in AD demonstrated that, at 16 weeks, Eczema Area and Severity Index (EASI) 75 and Investigator’s Global Assessment (IGA) 0/1 were achieved by 60.6% and 44.6% of patients taking lebrikizumab at its highest dose (vs 24.3% and 15.3% of patients taking placebo, respectively). Moreover, treatment with lebrikizumab was associated with rapid improvement of pruritus and low rates of conjunctivitis (1.4%-3.8%). Another IL-13 monoclonal antibody, tralokinumab, was evaluated for safety and efficacy in moderate-to-severe AD. By week 12, among adults receiving 300 mg tralokinumab, 42.5% achieved EASI-75 and 26.7% achieved IGA 0/1 score (vs 15.5% and 11.8% in the placebo group, respectively). Both lebrikizumab and tralokinumab demonstrated acceptable safety profiles in AD (and non-AD) trials with adverse events often being comparable between treatment and control groups. Thus, IL-13 inhibitors may provide a safe and effective treatment alternative for patients with moderate-to-severe AD.


Author(s):  
Haigen Cheng ◽  
Cong Hu ◽  
Yong Jiang

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.


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