A Global Energy Approach for Analysis of a Propagating Buckle in Submarine Pipelines

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Mingqiao Tang ◽  
Jianghong Xue ◽  
Renhuai Liu
Keyword(s):  
Steady State ◽  
Transition Zone ◽  
Plastic Material ◽  
External Pressure ◽  
Thick Wall ◽  
Yield Coefficient ◽  
Rigid Plastic ◽  
Stretching Factor ◽  
Buckle Propagation ◽  
Membrane Stretching

This paper presents a unique approach to analyze the steady-state buckle propagation phenomenon in underwater pipelines. In previous work, we restudied the buckling of a very long pipeline subjected to external pressure and found that buckling happens only over a certain length of the pipeline. In this paper, the collapse mode of the pipeline obtained in previous studies is taken as the transition zone during steady-state buckle propagation. Kinematics in the transition zone is analyzed based on von Kármán–Donnell type of nonlinearity. Assuming linear elastic rigid plastic material properties, the mechanical responses in the transition zone are examined using the deformation theory. Two parameters, the yield coefficient and the membrane stretching factor, are introduced to depict the effects of transversal bending and the membrane stretching, respectively. Analytical solution of buckle propagation pressure is derived by considering the energy conversation calculated from shell theory. It is found that the buckle propagation performance is governed by the transversal bending, including the circumferential bending and longitudinal bending. The membrane stretching is significant only for thick wall pipeline, in particular when the ratio of radius-to thickness is small than ten. The analysis is in effect by comparing the obtained solutions with the well-established predictions and the experimental results.

Buckle Propagation Analysis of Deep-Water Petroleum Transmission Pipelines with Axial Tension

2014 ◽  
Vol 1008-1009 ◽  
pp. 1134-1143 ◽  
Author(s):  
Sun Ting Yan ◽  
Yin Fa Zhu ◽  
Zhi Jiang Jin ◽  
Hao Ye
Keyword(s):  
Plastic Hinge ◽  
External Pressure ◽  
Isotropic Hardening ◽  
Rigid Plastic ◽  
Perfectly Plastic ◽  
Fitting Procedure ◽  
Plastic Materials ◽  
Buckle Propagation ◽  
Elastic Perfectly Plastic ◽  
Hinge Model

Quasi-static finite element simulation is carried out on buckle propagation phenomenon of offshore pipelines under external pressure. Arc-length method and volume-controlled static analysis by employing hydrostatic fluid element F3D4 are employed to calculate the steady buckle propagation pressure. After verifying the validity of numerical model, emphasis is on the influence of tension on propagation pressure considering isotropic hardening elastoplastic and elastic-perfectly plastic materials. Parametric study is conducted to include the effect of diameter-thickness ratio, after which two empirical equations are derived by curve fitting procedure. Finally, some comments on the results obtained through rigid-plastic hinge model are presented and a modified plastic hinge model including effect of material anisotropy is derived. The results can serve as a reference for more reasonable design of buckle arrestors.

On the Propagation of Bulges and Buckles

1984 ◽  
Vol 51 (2) ◽  
pp. 269-277 ◽  
Author(s):  
E. Chater ◽  
J. W. Hutchinson
Keyword(s):  
Steady State ◽  
Critical Pressure ◽  
External Pressure ◽  
Instability Mode ◽  
Instability Modes ◽  
Buckle Propagation ◽  
State Propagation

Two examples illustrate the propagation of instability modes under quasi-static, steady-state conditions. The first is the inflation of a long cylindrical party balloon in which a bulge propagates down the length of the balloon. The second is the collapse of a long pipe under external pressure as a result of buckle propagation. In each example, there is a substantial barrier to the initiation of the instability mode. Once initiated, however, the mode will not arrest if the pressure is in excess of the quasi-static, steady-state propagation pressure. It is this critical pressure that is determined in this paper for each of the two examples.

Stamping Rectangular Plates into Doubly-Curved Dies

1984 ◽  
Vol 198 (2) ◽  
pp. 109-125 ◽  
Author(s):  
T X Yu ◽  
W Johnson ◽  
W J Stronge
Keyword(s):  
Plastic Material ◽  
Rectangular Plates ◽  
Rigid Plastic ◽  
Punch Force ◽  
Plate Buckling ◽  
Rigid Plastic Material ◽  
Force Contact ◽  
Curvature Distribution ◽  
Doubly Curved ◽  
Deformation Modes

Shallow spheroidal shell segments have been press formed from rectangular plates by stamping between a die and matching punch that have two degrees of curvature. Experiments on mild steel, copper and aluminium plates that were not clamped in the die have measured the punch force, contact regions and final curvature distribution; and have observed plate buckling for a range of die curvature ratios and plate sizes. An analysis based on a rigid/plastic material idealization and decoupled in-plane forces and bending moments has been correlated with these experiments. The sequence of deformation modes has been identified; initially these are bending but in later stages, in-plane forces predominate.

Places and Causes of Mismanaged Plastic Materials in the Life Cycle of Flexible Plastic Packaging Based on Mechanical Recycling Context

2021 ◽  
Vol 888 ◽  
pp. 129-138
Author(s):  
Munzir Hadengganan ◽  
Djoko Sihono Gabriel
Keyword(s):  
Life Cycle ◽  
Plastic Material ◽  
Life Cycles ◽  
Plastic Waste ◽  
Production Cycle ◽  
Mechanical Recycling ◽  
Rigid Plastic ◽  
Plastic Packaging ◽  
Quality Degradation ◽  
Plastic Materials

Plastic waste has become a big issue in the world for its large amount of plastic waste in the sea. Most of the plastic waste is plastic packaging which consists of flexible and rigid plastic packaging. This research discusses flexible plastic packaging. Until now, most researches on the loss of plastic materials discuss how to manage plastic waste disposal once it has been used by community: only a few discuss production cycle: while none of them discusses flexible plastic packaging area. This research aims to examine the number of mismanaged materials throughout flexible plastic packaging life cycle using a combination of Material Flow Analysis (MFA) and Life Cycle Analysis (LCA). Based on the literature review, interviews and observations conducted by the author to all stakeholders in the life cycle of flexible plastic packaging, mismanagement of plastic material occurred in each cycle, mostly caused by quality degradation of flexible plastic that could cause plastic waste was not acceptable in the mechanical recycle. The results of this study show that: (1) mismanaged material occurred in all cycles throughout the life cycles of flexible plastic packaging, (2) quality degradation is the main caused of mismanaged material in several cycles, and (3) the mismanaged materials in the life cycle of flexible plastic packaging were 98.29%.

Theory of compression of a compressible rigid-plastic material

1974 ◽  
Vol 10 (3) ◽  
pp. 323-326
Author(s):  
I. S. Degtyarev ◽  
V. L. Kolgomorov
Keyword(s):  
Plastic Material ◽  
Rigid Plastic ◽  
Rigid Plastic Material

Rigid-Plastic Collapse of Cylindrical Shells

1973 ◽  
Vol 95 (1) ◽  
pp. 215-218 ◽  
Author(s):  
H. M. Haydl ◽  
A. N. Sherbourne
Keyword(s):  
Limit Analysis ◽  
Cylindrical Shells ◽  
Numerical Approach ◽  
External Pressure ◽  
Plastic Collapse ◽  
Rigid Plastic ◽  
Limit Loads ◽  
Complex Problems ◽  
Safe Side ◽  
Von Mises

This paper suggests a simple numerical approach to the limit analysis of cantilever cylindrical shells. The loads considered are external pressure and external pressure combined with a moment at the free shell end. It is shown that the collapse loads are within 4.5 percent on the safe side of the exact von Mises limit loads. The extension of the method of analysis to more complex problems is suggested.

scholarly journals Effective Utilization of Limonitic Nickel Laterite via Pressurized Densification Process and Its Relevant Mechanism

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 750
Author(s):  
Yuxiao Xue ◽  
Deqing Zhu ◽  
Jian Pan ◽  
Zhengqi Guo ◽  
Congcong Yang ◽  
...  
Keyword(s):  
Industrial Application ◽  
External Pressure ◽  
Front Velocity ◽  
Thick Wall ◽  
Thin Wall ◽  
Sintering Process ◽  
Effective Utilization ◽  
New Process ◽  
Fuel Rate ◽  
Mineral Compositions

Limonitic laterite contains low iron and nickel grades and much high smelting minerals and loss on ignition (LOI), identified as refractory iron ore for sintering. Thus, sinter pot tests of limonitic laterite via pressurized densification sintering and its intensification mechanism were conducted, and the industrial application prospect was explored. The results indicate that the sintering performance of the limonitic laterite of the new process is significantly improved with the tumble index and productivity increased by 19.2% and 18.6%, respectively, and solid fuel rate lowered by 10.3%. The external pressure field promotes the synchronization of heat front velocity and combustion front velocity for better sintering heat and mass transfer conditions, which also greatly improves the mineral compositions and microstructure of the product sinter. The microstructure is converted from large thin-wall pores into small thin-wall or large thick-wall pores with the sinter porosity decreased by 42.4%. Much close interlocking texture between hercynite and silico-ferrite of calcium and alumina (SFCA) is formed with hercynite grains aggregation and growth, and SFCA amount substantially increased. The better sintering performance will bring about a remarkable economic benefit of 282.78 million RMB/a if the industrial application is implemented. The pressurized densification sintering process is considered as one of the effective technologies for improving limonitic laterite sintering.

Sign in / Sign up

Export Citation Format

Share Document