scholarly journals Experimental and Numerical Investigation of a Method for Strengthening Cold-Formed Steel Profiles in Bending

2020 ◽  
Vol 10 (11) ◽  
pp. 3855 ◽  
Author(s):  
Ehsan Taheri ◽  
Ahmad Firouzianhaji ◽  
Peyman Mehrabi ◽  
Bahador Vosough Hosseini ◽  
Bijan Samali

Perforated cold-formed steel (CFS) beams subjected to different bending scenarios should be able to deal with different buckling modes. There is almost no simple way to address this significant concern. This paper investigates the bending capacity and flexural behavior of a novel-designed system using bolt and nut reinforcing system through both experimental and numerical approaches. For the experiential program, a total of eighteen specimens of three types were manufactured: a non-reinforced section, and two sections reinforced along the upright length at 200 mm and 300 mm pitches. Then, monotonic loading was applied to both the minor and major axes of the specimens. The finite element models were also generated and proved the accuracy of the test results. Using the proposed reinforcing system the flexural capacity of the upright sections was improved around either the major axis or minor axis. The 200 mm reinforcement type provided the best performance of the three types. The proposed reinforcing pattern enhanced flexural behavior and constrained irregular buckling and deformation. Thus, the proposed reinforcements can be a very useful and cost-effective method for strengthening all open CFS sections under flexural loading, considering the trade-off between flexural performance and the cost of using the method.

2012 ◽  
Vol 466-467 ◽  
pp. 225-228
Author(s):  
Kan Kang ◽  
Peng Zhang ◽  
Feng Tao Liu

Based on the the self-developed prestressed CFRP plate anchorage,the test specimens comprised 5 RC beams strengthened with the way the external prestressed CFRP plates,the research on the different prestressed tension and different span beam about the influence of the bending capacity , ultimate bearing capacity,cross section strain, CFRP strain and deflection of the test reinforced beams on the research. The test results showed that: the externally prestressed CFRP plate can obviously increase of the flexural performance of RC beams, and improve the utilization rate of the strength of the CFRP plate, through the external prestressed anchor of CFRP plate for a tension, reducing the RC beams crack, and improving the ductility of the RC beams.


2021 ◽  
Vol 26 (2) ◽  
pp. 163-173
Author(s):  
Maria Yasinta Menge Making ◽  
Ali Awaludin ◽  
Bambang Supriyadi

The capacity and behaviour of cold-formed steel built-up sections are affected by the arrangement of the connections. This study aims to determine the effect of the screw spacing to the bending capacity and behaviour of the cold-formed steel built-up box section which made from lipped-channel (1.0 mm thick, 81 mm web height, 8.5 mm lip height, upper and lower wing width 38 mm and 40 mm). A total of 19 beams with a length of 1200 mm each are subjected to pure bending moments by applying two point loads spaced 600 mm in the midspan. The screw spacing variations in the moment span are 100 mm, 150 mm, 200 mm, 250 mm, 300 mm, 328 mm, and 350 mm. The test results show the average of bending capacity of the beam test is increasing with the reduction in screw spacing while the screw configuration also affects the beam capacity. Analysis of the bending capacity using the effective width method and the direct strength method based on AISI S100-16 gives very conservative results. The failure mode of the built-up box sections were observed in the form of local buckling, distortion, and lateral-torsional buckling. 


The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.


2021 ◽  
Vol 624 (2) ◽  
pp. 16-24
Author(s):  
Yu. M. Pimenov ◽  
◽  
A. V. Ulit’ko ◽  
V. A. Sereda ◽  
◽  
...  

The cost-effective method of fuels and lubricants performance properties requirements management is proposed. Method ensures effectiveness enhancement of equipment and of fuels and lubricants life cycles; it includes requirements establishment (constructing of conceptual and empirical models of requirements), their quantitative expression through highly informative indicators of fuels and lubricants propensity for transformations, then approbation with the use of laboratory, bench and test stands tests, specification, assessment of realization in real world equipment operational conditions, effectiveness evaluation and modification of requirements. Some illustrations of application of the new method phases with regards to motor fuels and hydraulic fluid are provided.


2012 ◽  
Vol 166-169 ◽  
pp. 1797-1800
Author(s):  
Hong Chang Qu ◽  
Hong Yuan Li ◽  
Xuan Zhang

This paper investigates the flexural performance of FRP/FRC hybrid reinforcement system as well as FRP/plain concrete beams. Test results showed that the crack widths of FRP/FRC beams were smaller than those of FRP/plain concrete beams at the different corresponding load. With the increase of load, the crack spacing slightly decreased. The plain concrete beams failed in a more brittle mode than the FRC beams. Once they reached their ultimate moments, the load dropped fleetly. Compared to the companion beam, the addition of fibers improved the flexural behavior.


Author(s):  
Samuel L. Golinkin ◽  
Michael J. Lipski ◽  
John S. Loudon ◽  
Gennaro J. DiOrio ◽  
Timothy Ewer

Turbine blades with radial fasteners (T-shank, radial fir-tree, etc.) are commonly used in current steam turbomachinery, especially in power generation applications. However, this reliable and cost-effective design is limited by the strength of the axial pins which lock the closing part in the radial entry slot in the disc. In applications with high speed rotors or heavy blades, the centrifugal force of the blade exceeds the pin strength. In those applications, the airfoil portion of the closing blade is cut off leaving only the bottom portion which is located in the radial entry slot. Some original equipment manufactures (OEMs) also remove the airfoil of the blade 180 degrees opposite for better balancing. The absence of two airfoils is detrimental to efficiency and reliability of the entire row. Siemens Demag Delaval Turbomachinery, Inc. (SDDTI) developed a new locking arrangement which eliminates the above described shortcoming associated with standard radial entry blades. This paper presents the design of the new patented locking arrangement and mechanical stress calculations (FEA) of its major components. In order to verify the validity of the design and calculations, a full-scale row of modernized radial entry blades for an existing US Navy turbine with the new locking arrangement was tested. The testing was done over the full range of operating speeds in a vacuum bunker. The paper also describes the special test rotor, instrumentation used, and the test results which were compared with the stress calculations. The tests confirmed all the advantages of the new locking arrangement and showed acceptable correlation with the stress calculations. The patented design will expand applications for radial entry blades, modernize radial entry blades with missing blade airfoils, and provide a cost-effective method to repair localized cracks in the fastener area of the turbine discs.


2012 ◽  
Vol 535-537 ◽  
pp. 1985-1990
Author(s):  
Bao Ku Qi ◽  
Jing Ming Zhao ◽  
Yu Qu

Low-carbon building is the new building types under the background of low-carbon economy. Compared with traditional architectural form, the cost and benefit of the low-carbon building have changed a lot; therefore, it is necessary to analyze the low-carbon building from the perspective of cost and benefit. This paper structured an analysis mode through the cost-effective method, and also provided a new analysis idea and approach to value the low-carbon building, so it has an important referential value for the promotion and construction of low-carbon building in the whole society.


2020 ◽  
Author(s):  
Mónica Palmero Fernández

This article presents a cost-effective method for digitising photographic film for archival purposes using a DSLR camera, focussing on the widely used colour reversal Kodachrome film produced by Eastman Kodak between 1935 and 2009. I discuss the digitisation of an archive of 787 Kodachrome slides taken between 1988 and 1989 during the excavation of Jemdet Nasr, an archaeological site located in southern Iraq (Project website). I compare results obtained using a film scanner (Nikon Coolscan IV ED) with two different scanning software solutions (SilverFast and VueScan), a flatbed scanner (HP Scanjet 8300), and two DSLR cameras with macro lens (a Canon EOS KissX3 with 105mm lens and a Canon EOS 80D with 90mm lens). The results demonstrate the cost-effective value of the DSLR method for archives where time and resources are limited, but where digital photography equipment might be readily available, such as an archaeological unit or a university department. The method allows for high quality, fast and economical digitisation of excavation and collection archives that will enhance research. The method also offers superior results in rendering the high dynamic range of photographic film such as Kodachrome.


Author(s):  
Danielle M. Gillard ◽  
Jeffrey D. Sharon

Abstract Purpose of Review To summarize and critically review recent literature on the relative cost-effectiveness of hearing augmentation versus stapes surgery for the treatment of otosclerosis. Recent Findings Otosclerosis leads to reduced patient quality of life, which can be ameliorated by either stapes surgery, or hearing aid usage. The success of stapes surgery is high, and the risks of serious postoperative complications are low. Hearing aids don’t have the complications of surgery but are associated with long-term costs. Cost-effectiveness models have shown that stapes surgery is a cost-effective method for treating otosclerosis. Summary Both stapes surgery and hearing aids can improve patient-reported quality of life in otosclerosis. Stapes surgery has larger upfront costs and surgical risks, but hearing aids are associated with longer lifetime costs. Stapes surgery is cost-effective for the treatment of otosclerosis.


Author(s):  
Glenn A. Fager

During 1993 and 1994, the Kansas Department of Transportation constructed a 15.25-km full-depth asphalt-rubber project on I-135. Three test sections were finished in 1994 along with one control section in 1995. The test sections consisted of both a thick and thin asphalt-rubber section over rubblized portland cement concrete pavement (PCCP) and a completely reconstructed asphalt-rubber section. The control section was built over rubblized PCCP to the same thickness as the thick asphalt-rubber section. Approximately 172 000 metric tons of asphalt-rubber were produced using the wet (reacted) process. Data indicated that the asphalt-rubber mix cost approximately 50 percent more than the asphalt-only mix. Reducing the thickness of the asphalt-rubber from 225 mm to 180 mm would allow the cost to become equal to the asphalt-only control section. Equal performance of the reduced thickness section or longer performance from the 225-mm asphalt-rubber section would be a cost-effective method of using tire rubber in asphalt pavements. Test data indicate a stable mix and adequate thermal characteristics but high permeabilities. Performance after 6 winter months under traffic indicates no raveling, rutting, flushing, cracking, or moisture damage.


Sign in / Sign up

Export Citation Format

Share Document