scholarly journals Bending-induced local buckling during offshore installation of multi-layered FRP pipelines

2021 ◽  
Vol 1201 (1) ◽  
pp. 012042
Author(s):  
D Pavlou ◽  
N D Adasooriya
Keyword(s):  
Pipe Wall ◽  
Local Buckling ◽  
High Strength ◽  
Oil Industry ◽  
Specific Weight ◽  
Bending Moments ◽  
Glass Fiber Reinforced ◽  
Bending Stresses ◽  
Lamination Theory ◽  
The Cost

Abstract In the last two decades FRP pipelines have attracted the attention of the oil industry because of their high strength, excellent fatigue performance and low specific weight. On the other hand, the final cost of installation of FRP pipelines is comparable to the cost of carbon steel ones. Therefore, their implementation in offshore applications seems to be advantageous. During offshore installation, the curvatures of the pipes during the S-lay or J-lay installation processes cause high bending stresses and risk for bending-induced local buckling. Since the pipe wall is multi-layered and the laminae are anisotropic, the calculation of critical bending moments is difficult. In the present work, an analytical solution of critical bending moments for bending-induced local buckling is provided. The proposed method uses the classical lamination theory of multi-layered anisotropic materials and Flügge’s assumption for local buckling analysis of pipelines. Results for E-Glass fiber reinforced polymeric pipelines are provided and discussed.

Thermal Expansion by Lateral Buckling: Structural Reliability Analysis for the Penguins Flowline

2004 ◽  
Author(s):  
Ralf Peek ◽  
Ian Matheson ◽  
Malcolm Carr ◽  
Paul Saunders ◽  
Nigel George
Keyword(s):  
Thermal Expansion ◽  
Reliability Analysis ◽  
Structural Reliability ◽  
Pipe Wall ◽  
Local Buckling ◽  
Companion Paper ◽  
Bending Moments ◽  
Global Response ◽  
Structural Reliability Analysis ◽  
Full Scale Tests

The Penguins pipeline is a 60 km PIP system designed to buckle laterally on the seabed. This is an effective way to accommodate thermal expansion. However excessive bending could lead to local buckling or wrinkling of the pipe wall. Existing design criteria based on load-controlled or displacement-controlled conditions are not directly applicable here, because the actual conditions fall somewhere in between. For this reason a structural reliability analysis has been performed for the Penguins flowline, to demonstrate that it is safe to allow the flowline to buckle laterally. Thereby the uncertainties that can affect the peak bending moments and curvatures at the buckles are addressed explicitly i.e. one does not rely on an assumption of load- or displacement control. This paper describes how describes how the various uncertainties are combined to assess the structural reliability. Details of the various inputs, including full-scale tests and finite element analyses addressing both global response and local buckling or wrinkling to develop the capacity and response functions are reported in a companion paper.

Tax maneuver in the oil industry: Provisional results and risks for further implementation

2020 ◽  
pp. 28-43
Author(s):  
A. S. Kaukin ◽  
E. М. Miller
Keyword(s):  
Oil Industry ◽  
Oil Products ◽  
Oil Refining ◽  
State Budget ◽  
Tax Rate ◽  
Oil Companies ◽  
Reform Plan ◽  
Alternative Variant ◽  
Calculation Results ◽  
The Cost

The paper analyzes the consequences of the abolition of the export duty on oil and oil products as a necessary step to stimulate energy efficiency of Russia’s economy and eliminate underdevelopment provoked by a long-term subsidizing of inefficient oil refining sector in Russia. The calculation results have shown that even taking into account several deviations from the planned scenarios of changing the parameters of tax regulation of the oil industry in 2014— 2019, the tax maneuver brought over 3.5 trillion rubles (in 2019 — 148 billion rubles) to the state budget in 2014—2017, mainly due to an increase in the base mineral extraction tax rate, and contributed to an increase in the depth of oil refining from 72% to 85%. In addition, the article analyzes possible risks associated with the current plan for reforming the taxation of the industry until 2024 and proposes an alternative that could level some of them. A comparative analysis of the effects of the tax maneuver under the current reform plan and the alternative variant suggests that the latter will allow to achieve a greater total budgetary effect in four years, reduce the cost of subsidizing domestic oil refining, increase the efficiency of Russian vertically integrated oil companies, and reduce the growth rate of oil products prices in the retail market.

scholarly journals Materials for Automotive Lightweighting

2019 ◽  
Vol 49 (1) ◽  
pp. 327-359 ◽  
Author(s):  
Alan Taub ◽  
Emmanuel De Moor ◽  
Alan Luo ◽  
David K. Matlock ◽  
John G. Speer ◽  
...  
Keyword(s):  
Galvanic Corrosion ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
New Materials ◽  
Specific Strength ◽  
Advanced High Strength Steels ◽  
Strength And Stiffness ◽  
The Cost

Reducing the weight of automobiles is a major contributor to increased fuel economy. The baseline materials for vehicle construction, low-carbon steel and cast iron, are being replaced by materials with higher specific strength and stiffness: advanced high-strength steels, aluminum, magnesium, and polymer composites. The key challenge is to reduce the cost of manufacturing structures with these new materials. Maximizing the weight reduction requires optimized designs utilizing multimaterials in various forms. This use of mixed materials presents additional challenges in joining and preventing galvanic corrosion.

Study on the Local Buckling Behavior of Steel Equal Angle Members under Axial Compression with the Steel Strength Variation

2011 ◽  
Vol 374-377 ◽  
pp. 2430-2436
Author(s):  
Gang Shi ◽  
Zhao Liu ◽  
Yong Zhang ◽  
Yong Jiu Shi ◽  
Yuan Qing Wang
Keyword(s):  
Finite Element ◽  
Axial Compression ◽  
High Strength Steel ◽  
Local Buckling ◽  
Steel Structures ◽  
High Strength ◽  
Element Analysis ◽  
Equal Angle ◽  
Buckling Behavior ◽  
Steel Strength

High strength steel sections have been increasingly used in buildings and bridges, and steel angles have also been widely used in many steel structures, especially in transmission towers and long span trusses. However, high strength steel exhibits mechanical properties that are quite different from ordinary strength steel, and hence, the local buckling behavior of steel equal angle members under axial compression varies with the steel strength. However, there is a lack of research on the relationship of the local buckling behavior of steel equal angle members under axial compression with the steel strength. A finite element model is developed in this paper to analyze the local buckling behavior of steel equal angle members under axial compression, and study its relationship with the steel strength and the width-to-thickness ratio of the angle leg. The finite element analysis (FEA) results are compared with the corresponding design method in the American code AISC 360-05, which provides a reference for the related design.

Generation of Cyclic Stress-Strain Curves for Sheet Metals

2000 ◽  
Author(s):  
K. M. Zhao ◽  
J. K. Lee
Keyword(s):  
Constitutive Model ◽  
Kinematic Hardening ◽  
Optimization Procedure ◽  
High Strength ◽  
Cyclic Stress ◽  
Bending Moments ◽  
Sheet Metals ◽  
Stress Strain ◽  
Normal Anisotropy ◽  
Material Parameters

Abstract The main objective of this paper is to generate cyclic stress-strain curves for sheet metals so that the springback can be simulated accurately. Material parameters are identified by an inverse method within a selected constitutive model that represents the hardening behavior of materials subjected to a cyclic loading. Three-point bending tests are conducted on sheet steels (mild steel and high strength steel). Punch stroke, punch load, bending strain and bending angle are measured directly during the tests. Bending moments are then computed from these measured data. Bending moments are also calculated based on a constitutive model. Normal anisotropy and nonlinear isotropic/kinematic hardening are considered. Material parameters are identified by minimizing the normalized error between two bending moments. Micro genetic algorithm is used in the optimization procedure. Stress-strain curves are generated with the material parameters found in this way, which can be used with other plastic models.

Steady and transient state tests on local buckling of high strength Q690 steel stub columns

2021 ◽  
Vol 167 ◽  
pp. 108214
Author(s):  
Ahmed Sharhan ◽  
Weiyong Wang ◽  
Xiang Li ◽  
Hisham Al-azzani
Keyword(s):  
Local Buckling ◽  
Transient State ◽  
High Strength ◽  
State Tests ◽  
Stub Columns

Local buckling behaviour of high strength steel welded box-section columns under axial compression

2022 ◽  
Vol 171 ◽  
pp. 108677
Author(s):  
Bing Li ◽  
Chao Cheng ◽  
Zhimin Song ◽  
Xianlei Cao ◽  
Zhengyi Kong
Keyword(s):  
Axial Compression ◽  
High Strength Steel ◽  
Local Buckling ◽  
High Strength ◽  
Box Section

CHANGES IN THE TECHNICAL AND TECHNOLOGICAL LEVEL OF STEAM CULTIVATORS IN THE XXI CENTURY

2021 ◽  
Vol 2 (143) ◽  
pp. 174-183
Author(s):  
Andrey Yu. Nesmiyan ◽  
◽  
Anastasiya S. Kaymakova ◽  
Yuliya S. Tsench ◽  
Keyword(s):  
Weighted Average ◽  
Specific Weight ◽  
Research Purpose ◽  
Utilization Rate ◽  
Average Value ◽  
Technological Level ◽  
Short Test ◽  
Specific Material ◽  
The Cost

Most modern agricultural machines and tools consist of components, the main parameters, design features of which were justified in the first half of the twentieth century. Slowly and evolutionarily, these technical means are developing. (Research purpose) The research purpose is in identifying general trends in the technical and technological level of steam cultivators in the first quarter of the XXI century. (Materials and Methods) For the study there was analyzed the data of the short test reports of the selected machines. The production of steam cultivators in the Russian Federation is gradually increasing. (Results and discussion) For ten years of the beginning of the XXI century, only 27 machines were provided for testing, and from 2014 to 2017 – more than 40, while for "old" cultivators, the weighted average value of the tractor traction class was 2.8, for new ones it is about of four. For the study period (on average 10 years) the quality of soil cultivation in terms of such parameters as deviation from the specified depth of cultivation, crumbling and combing of the field surface has not changed much. The productivity of cultivator units increased by 7-21 percents, which is explained not only by an increase in the power of tractors, but also by an increase in the utilization rate of charge time on average from 0.72 to 0.77. The specific weight of the "new" cultivators was on average 22 kilogram-meters less than that of the "old" analogues, which can be explained by the evolution of their designs. (Conclusions) Increasing the class of tractors by one "level" the specific material consumption of the cultivators aggregated with them increases by about 58 kilogram-meters for both "old" and " new " cultivators. With an increase in the width of the tools from 4 to 16 meters, their weight will increase by 8 times, which affects the cost and operational and environmental characteristics of wide-reach cultivators.

On the presence of bending stresses in inflated thin-walled structures

1997 ◽  
Vol 211 (5) ◽  
pp. 341-348 ◽  
Author(s):  
G G Chew ◽  
I C Howard ◽  
E A Patterson
Keyword(s):  
Thin Sheet ◽  
Large Change ◽  
Radius Of Curvature ◽  
Finite Element Models ◽  
Bending Moments ◽  
Membrane Structures ◽  
Thin Walled Structures ◽  
Sheet Structure ◽  
Bending Stresses ◽  
Single Radius

It is proposed that, in appropriate circumstances, membrane structures can experience bending moments. On uniformly inflating a thin sheet structure, which has a shape consisting of multiple curvatures, the structure will deform in such a way that the final shape will have a single radius of curvature, assuming that failure does not occur. It is the large change of shape from a multicurvature surface to a single curvature surface that causes bending moments to exist within a membrane. The validity of the hypothesis has been demonstrated using four finite element models, including an elliptical cylinder, an ellipsoid, a ‘double’ cone and a trileaflet heart valve.

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