scholarly journals Numerical Study on the Local Buckling Behaviour of Bolted Steel Plates in Steel Jacketing

2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
Xiao-liang Xu ◽  
Zhou-dao Lu ◽  
Ling-zhi Li ◽  
Chang-jiu Jiang

A numerical simulation was conducted to investigate the local buckling behaviour of the bolted steel plates in steel jacketing technique. The numerical model was firstly validated by the results of a previous experimental study. Then a parametric study was conducted to investigate the influence of different restraint measures on the local buckling behaviour and the sensitivity of the buckling behaviour to the initial imperfection. Fitted formulae were developed to calculate the structural field capacity of the bolted steel plates, and recommended values of stiffener size were also provided to facilitate the strengthening design of steel jacketing.

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3623
Author(s):  
Jyh-Haw Tang ◽  
Aisyah Dwi Puspasari

Scouring is one of the most common potential causes of bridge pile foundation failure, with loss of life, economic and environmental impacts. Comprehensive studies on the numerical simulation of local scour around pile groups are still limited. This paper presents a numerical simulation using Flow-3D software to calculate the maximum sediment scour depth and investigate the mechanism around the groups of three cylinders in a tandem arrangement. A validation using the experimental study was carried out to confirm the reliability of the present numerical model. By using the Van Rijn transport rate equation and RNG k-ε turbulence model, the results of time evolution of scour depth and bed elevation contour show good agreement with the experimental study. The numerical simulation of three cylinders in a tandem arrangement were conducted with pile spacing ratios, G/D of 2 and 3. The local scour is affected by the horseshoe vortex from the downflow driven by the downward pressure gradient and rotates in front of the pile and the high bed shear stress, triggered by flow acceleration. The deepest maximum local scour depth is always obtained by the front pile as a shield pile, followed by the piles behind. The trend of the maximum local scour depth in a tandem arrangement is in accordance with the experimental studies and has a better agreement than previous numerical studies with the same model setup. This means that the numerical model used to simulate pile groups is accurate and capable of calculating the depth of sediment scour.


Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 141
Author(s):  
Yahui Shi ◽  
Ang Hu ◽  
Taisheng Du ◽  
Xinke Xiao ◽  
Bin Jia

To demonstrate the importance of incorporating Lode angle into fracture criterion in predicting the penetration resistance of high-strength steel plates, ballistic tests of blunt-nosed projectiles with a diameter of 5.95 mm impacted 4 mm thick Weldox 900 E steel plates were conducted. Impacting velocity range was 136.63~381.42 m/s. The fracture behavior and the ballistic limit velocities (BLVs) were obtained by fitting the initial-residual velocities of the projectiles. Subsequently, axisymmetric finite element (FE) models parallel to the tests were built by using Abaqus/Explicit software, and the Lode-independent Johnson–Cook (JC) and the Lode-dependent ASCE fracture criterion were incorporated into the finite element model for numerical simulation. Meanwhile, to verify the sensitivity of the mesh size in the numerical simulation, different mesh sizes were used in the shear plug area of the target. It can be found that Weldox 900 E steel has obvious mesh size sensitivity by comparing the experimental results and numerical simulation, and the JC fracture criterion and the ASCE fracture criterion predicted similar BLV for the same mesh size.


2021 ◽  
Author(s):  
Soufiane el Ogri ◽  
Charles-Darwin Annan ◽  
Pampa Dey

<p>This article concerns the behaviour of two blind bolt types, Ajax One side and Blind Oversize Mechanically (BOM), used to connect a multi-void aluminum bridge deck on its supporting steel girders. An extensive numerical simulation by FEM was performed to evaluate the connection behaviour against the Canadian Highway Bridge Design standard CSA S6-19. The main objective was to examine the assembly against fretting and quantify its impact at the contact zone over several load cycles. A special numerical model was developed for the prediction of fretting, and validated with analytical results and other observations reported in the literature. The model was used to analyze the fretting for each bolt at the surface of contact between the bolt head and the aluminum plate. Results of the study revealed that the blind bolts will lead to a few micrometers of wear, while for the standard bolt, a probable crack developments associated with minor wear may occur at the contact area.</p>


2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Ker Shin Mu ◽  
Poi Ngian Shek ◽  
Arizu Sulaiman ◽  
Boon Cheik Tan

This paper presents a parametric study on compound cold-formed steel sections as flexural members. The compound members are used to sustain higher load and solve the problems of local buckling and lateral torsional buckling. The aim of this study is to investigate the strength of compound cold-formed steel section subjected to pure bending. Moment capacity of the compound section is calculated in accordance to Eurocode 3. The compound cold-formed steel sections proposed in this study are made up of two cold-formed steel C-section and hot-rolled plates. Steel plates with thickness of 3 mm to 8 mm are added to the cold-formed double C-section with the purpose to increase the bending capacity. From the comparison, moment capacity of compound sections give higher value as compared to cold-formed steel C-section with the comparison ratios range between 1.15 and 3.30. Results from the study show that compound cold-formed steel sections able to enhance the strength in resisting pure bending by adding steel plate at the flanges and web of the section. On the other hand, finite element modeling using ANSYS is carried out on two of the selected compound cold-formed steel sections and the results show good agreement with analytical results.


2021 ◽  
Vol 39 (5) ◽  
pp. 1575-1582
Author(s):  
Mohammed Salah Belalem ◽  
Mohammed Elmir ◽  
Mohammed Tamali ◽  
Razli Mehdaoui ◽  
Abdelkrim Missoum ◽  
...  

In this work, we propose to experimentally and numerically study the natural convection in laminar regime in an agricultural greenhouse located in South West of Algeria and more precisely in the Adrar area. The numerical study is two-dimensional and was carried out on a tunnel greenhouse with an area of 180m2 located in Adrar in the southwest of Algeria (Latitude: 27°52′27″N, longitude: 0°17′37″W, the laltitude above sea level is 257 m), with polyethylene cover and houses two rows of tomato plants. The experimental study was made during the winter or flowering period of tomato plants (February) when the temperature difference outside the greenhouse is maximum: T min = 3℃ at night and T max = 20℃ the day. We used a calculate code based on the finite element method to numerically simulate the phenomenon of heat transfer inside the greenhouse. The results of the numerical simulation are in the form of isotherms, streamlines and variations in temperature and speed in the greenhouse. The value of the temperature calculated by numerical simulation at the position where the sensor has been placed will be compared with that measured by the sensor. It was concluded that to have a favorable environment for the growth of tomatoes, we must keep the openings closed especially during the night without needing a heating system, especially in this region characterized by a hyper arid climate.


2019 ◽  
Vol 12 (4) ◽  
Author(s):  
Sajida Kadhem Al-Jasmi ◽  
Haitham Al-Thairy

This paper presents a numerical simulation of the structural response of reinforced concrete (RC) beams under elevated temperature using the commercial finite element package ABAQUS. A numerical model is firstly suggested by selecting the appropriate geometrical and material properties of the RC beam model at elevated temperature. Thereafter, the suggested numerical model was validated against the experimental tests conducted in this study. The validation results in terms of temperatures- time histories; load-mid span deflection of the RC beams have confirmed the accuracy of the suggested numerical model. The validated numerical model was implemented in conducting a parametric study to investigate the effects of two important parameters on the behavior and failure of RC beams under elevated temperature. These parameters are the effect of the high ranges of elevated temperatures; and the effect of heating rate. The parametric study results have revealed that the failure load and the ductility of RC beams under elevated temperature are not considerably influenced by changing the heating rate. It has also been concluded that the ultimate load capacities of RC beams have considerably decreased by 55.49%, 74.72%, and 81.31% comparing with the control RC beam when they exposed to temperature values of 600 ºC, 700 ºC, and 800ºC respectively. These conclusions may be used in the design of RC beams subjected to fire induced temperature. Numerical model


Author(s):  
Jingru Zhang ◽  
Yogesh Jaluria ◽  
Tiantian Zhang ◽  
Li Jia

Multiple microchannel heat sinks for potential use for electronic chip cooling are studied experimentally and numerically to characterize their thermal performance. The numerical simulation is driven by experimental data, which are obtained concurrently, to obtain realistic, accurate and validated numerical models. The ultimate goal is to design and optimize thermal systems. The experimental setup was established and liquid flow in the multiple microchannels was studied under different flow rates and heat influx. The temperature variation versus time was recorded by thermocouples, from which the time needed to reach steady state was determined. Temperature variations under steady state conditions were compared with three-dimensional steady state numerical simulation for the same boundary and initial conditions. The experimental data served as input parameters for the validation of the numerical model. In case of discrepancy, the numerical model was improved. A fairly good agreement between the experimental and simulation results was obtained. The numerical model also served to provide input that could be employed to improve and modify the experimental arrangement.


Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1608
Author(s):  
Eduardo Nuñez ◽  
Nwar Boainy ◽  
Freddy González ◽  
Ronald Torres ◽  
Ricardo Picón ◽  
...  

Steel buildings with tubular columns showed a satisfactory performance during the Honshu (2011) earthquake, unlike steel buildings in the 1994 Northridge and 1995 Kobe earthquakes, where welded moment connections showed damage in their joints. In this research, a lateral joint using a hollow structural section (HSS)-beam and HSS-column subjected to cyclic displacement was performed. Three large-scale specimens were tested and a numerical model was calibrated, reaching a good adjustment. Later, several configurations of beams and columns were evaluated using finite element (FE) models from the numerical model previously calibrated. A flexural resistance higher 0.80 Mp at 0.04 [rad] was obtained for all cases studied. The ductility factor in the 3 specimens was lower than 2.5, therefore a non-ductile behavior was controlled in the connection. This aspect is very important although a 0.8 Mp at 0.04 [rad] was achieved. Finally, the typical welded moment connection can be improved using the bolted moment connection, which allows the concentration of inelastic incursion in the beam compared with the welded solution. However, a non-ductile behavior derived from local buckling in flanges of a tubular beam can affect the seismic performance.


2019 ◽  
Vol 11 (S1) ◽  
pp. 1-8
Author(s):  
P. Manikandan ◽  
A. Ezhilan

Abstract The objective of this study is to make the experimental and finite element simulations of buckling behaviour of cold-formed steel (CFS) built-up hat-shaped closed section under simply supported end condition subjected to two-point loading. Numerical simulation is carried out using the software ABAQUS. The test result is compared with numerical results and good correlation is achieved. Next, for validation, a series of parametric studies are carried out using the validated numerical model, such as the effect of length, depth, width, thickness and angle of the inclined element. The local buckling and the interaction of local and flexural buckling are studied. To end with, a design equation is proposed in accordance with the direct strength method specification for CFS structure.


2010 ◽  
Vol 168-170 ◽  
pp. 1921-1933
Author(s):  
Yuan Qing Wang ◽  
Huan Xin Yuan ◽  
Yong Jiu Shi ◽  
Ming Cheng

Low elastic modulus of aluminum alloy gives prominence to lateral and local buckling of members, especially when thin walled sections are adopted to save material usage. Under certain conditions of loads and constraint, local buckling would occur in aluminum beams. A numerical study to assess the local stability of aluminum I section beams is presented in this paper. The study focused on two aspects: the local buckling of aluminum flange plate under compression, the local buckling of aluminum web plate under bending and shear. An extensive parameter analysis including width-to-thickness ratio, initial imperfection, material constitutive relation and restriction effect from adjacent plates was carried out with the purpose of extracting several governing parameters and investigating their effects on the local buckling of aluminum plate. Based upon the results of finite element analysis (FEA), a new design method in connection with the local stability of aluminum I section beams has been developed. By virtue of the proposed design method, three key indicators that include the critical value of width-to-thickness ratio to prevent local buckling of aluminum flange plate under compression, the local stability of aluminum web plate under bending/shear and the bearing capacity of aluminum I section beams under the condition that the post buckling strength of web is taken into account, could be obtained to provide more rational and efficient designs. The proposed design method is different from the current Eurocode but acts in accordance with Chinese code for design of steel structures (Chinese steel code) in order to satisfy applicability.


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