Determination of collapse moment of different angled pipe bends with initial geometric imperfection subjected to in-plane bending moments

2021 ◽  
pp. 095440622199640
Author(s):  
Manish Kumar ◽  
Pronab Roy ◽  
Kallol Khan
Keyword(s):  
Finite Element ◽  
Cross Section ◽  
Circular Cross Section ◽  
Initial Imperfection ◽  
Bend Angle ◽  
Bending Moments ◽  
Element Analysis ◽  
Geometric Imperfection ◽  
Initial Geometric Imperfection

From the recent literature, it is revealed that pipe bend geometry deviates from the circular cross-section due to pipe bending process for any bend angle, and this deviation in the cross-section is defined as the initial geometric imperfection. This paper focuses on the determination of collapse moment of different angled pipe bends incorporated with initial geometric imperfection subjected to in-plane closing and opening bending moments. The three-dimensional finite element analysis is accounted for geometric as well as material nonlinearities. Python scripting is implemented for modeling the pipe bends with initial geometry imperfection. The twice-elastic-slope method is adopted to determine the collapse moments. From the results, it is observed that initial imperfection has significant impact on the collapse moment of pipe bends. It can be concluded that the effect of initial imperfection decreases with the decrease in bend angle from 150∘ to 45∘. Based on the finite element results, a simple collapse moment equation is proposed to predict the collapse moment for more accurate cross-section of the different angled pipe bends.

Finite Element Analysis on the Blast Resistant Performance of Multibarrel Tube-Confined Concrete Column in Different Cross-Sections

2013 ◽  
Vol 721 ◽  
pp. 545-550
Author(s):  
Sai Wu ◽  
Jun Hai Zhao ◽  
Er Gang Xiong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Detonation Wave ◽  
Cross Section ◽  
Cross Sections ◽  
Failure Modes ◽  
Circular Cross Section ◽  
Blast Load ◽  
Element Analysis ◽  
The Impact

Based on the finite element analysis software ANSYS/LS-DYNA, this paper numerically analyzed the dynamic performance of MTCCCs with different cross sections under blast load, followed by the study and comparison on the differences of the detonation wave propagation and failure modes between the columns in circular cross section and square cross section. The results show: The blast resistant performance of the circular component is more superior than the square component for its better aerodynamic shape that can greatly reduce the impact of the detonation wave on the column; The main difference of the failure modes between the circular and square cross-sectional components under blast load lies in the different failure mode of the outer steel tube. The simulation results in this paper can provide some references for the blast resisting design of MTCCCs.

scholarly journals Numerical Studies on the Stiffness of Arc Elliptical Cross-section Helical Spring Subjected to Circumference Force

Mechanika ◽  
2021 ◽  
Vol 27 (4) ◽  
pp. 327-334
Author(s):  
Yuan WANG ◽  
Qingchun WANG ◽  
Zehao SU
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Circular Cross Section ◽  
Elliptical Cross Section ◽  
Helical Spring ◽  
Element Analysis ◽  
Elliptical Cross ◽  
Stiffness Property ◽  
Regression Formula

 Due to its excellent properties, elliptical cross-section helical spring has been widely used in automobile industry, such as valve spring, arc spring used in Dual Mass Flywheel and so on. Existing stiffness formulae of helical spring remain to be tested, and stiffness property of elliptical cross-section arc spring has been little studied. Hence, study on the stiffness of elliptical cross-section helical spring is significant in the development of elliptical cross-section helical spring. This paper proposes a method to study the stiffness property of elliptical cross-section helical spring that the experiment design method is adopted with finite element analysis. Firstly, the finite element analysis method was used to verify the cylindrical (circular cross-section and elliptical cross-section) springs. Then, the regression formula was designed and derived compared with the reference springs’ stiffness formulae by experimental design. Last, regression formula was verified with existing experiment data. The novelty in this paper is that simulation technology of arc spring was investigated and a stiffness regression equation of arc elliptical cross-section spring was obtained using orthogonal regression design, with significance in wide use of the arc elliptical cross-section helical spring promotion. 

Evaluation of collapse moment of pressurized 30°–180° bend pipes subjected to out-of-plane bending moment

2021 ◽  
pp. 095440622110614
Author(s):  
Manish Kumar ◽  
Pronab Roy ◽  
Kallol Khan
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Plastic Material ◽  
Bending Moment ◽  
Bend Angle ◽  
Pipe Bend ◽  
Geometric Imperfection ◽  
Initial Geometric Imperfection ◽  
Out Of Plane ◽  
Plane Bending

The present paper determines collapse moments of pressurized 30°–180° pipe bends incorporated with initial geometric imperfection under out-of-plane bending moment. Extensive finite element analyses are carried out considering material as well as geometric nonlinearity. The twice-elastic-slope method is used to determine collapse moment. The results show that initial imperfection produces significant change in collapse moment for unpressurized pipe bends and pipe bends applied to higher internal pressure. The application of internal pressure produces stiffening effect to pipe bends which increases collapse moment up to a certain limit and with further increase in pressure, collapse moment decreases. The bend angle effect on collapse moment reduces with the increase in internal pressure and bend radius. Based on finite element results, collapse moment equations are formed as a function of the pipe bend geometry parameters, initial geometric imperfection, bend angle, and internal pressure for elastic-perfectly plastic material models.

Simulation of Sealing Performance of Elastomeric O-Ring Gasket Including Metal Skeleton

2014 ◽  
Vol 556-562 ◽  
pp. 615-619
Author(s):  
Guo Liang Zhang ◽  
Zhi Bin Zeng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Normal Force ◽  
Circular Cross Section ◽  
Contact Stresses ◽  
Element Analysis ◽  
Sealing Performance ◽  
And Performance ◽  
Maximum Contact

In the hydraulic and pneumatic equipments, the elastomeric O-ring gaskets are widely used to ensure their sealing. The sealing capability of an elastomeric O-ring gasket depends upon the contact stresses that develop between the O-ring and the surfaces with which it comes into contact. In order to increase the strength and service life of the general elastomeric O-ring gasket, this gasket including metal skeleton is gradually applied to the actual product in recent years. In spite of the sealing performance of the elastomeric O-ring gasket has been investigated in many literatures, few information of it is known about the elastomeric O-ring gasket including metal skeleton. If any gasket degrades or fails, the overall operation and performance of the production will be affected. This paper aims to study the contact stresses occurred on the metal skeleton seal structure under the various interference fits with three sectional forms (trapezoid cross section, square cross section and circular cross section). Finite element analysis is used to predict sealing performance of an installed metal skeleton seal, providing a normal force against the sealing surface. Results gained show that the contact stresses occurred on the metal skeleton seal is larger than it generated on the general elastomeric O-ring gasket. Furthermore, the metal skeleton seal possessed trapezoid cross section can produce the maximum contact stress, which will show the best sealing performance among three sectional forms.

Effects of Initial Geometric Imperfection on Stability of Single-Layer Reticulated Shell

2011 ◽  
Vol 368-373 ◽  
pp. 276-279
Author(s):  
Fei Hua Zheng ◽  
Jin Song Lei ◽  
Wen Zhi Yin
Keyword(s):  
Finite Element ◽  
Shell Structure ◽  
Single Layer ◽  
Initial Imperfection ◽  
Limited Capacity ◽  
Geometric Imperfection ◽  
Finite Element Software ◽  
Initial Geometric Imperfection ◽  
Overall Stability ◽  
The Stability

The stability of reticulated shell is a key issue for single-layer reticulated shell. In the paper, a single-layer arch-supported shell structure was analyzed by finite element software MIDAS. The eigenvalue buckling analysis and the geometric nonlinear overall stability analysis with initial imperfection of the model which carried two different load combinations were studied too. At the same time, the influences on the stability of the shell structure were researched. The results showed that the shell structure was sensitive to the initial imperfection. Under different load combinations, the instability of modes and limited capacity of stability are different in the shell structure.

Determination of Stress Concentration Around an Oblique Hole by a Finite-Element Technique

1983 ◽  
Vol 105 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Hua-Ping Li ◽  
F. Ellyin
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Maximum Stress ◽  
Plate Thickness ◽  
Two Dimensional ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Parametric Studies ◽  
Element Technique

A plate weakened by an oblique penetration of a circular cylindrical hole has been investigated. The stress concentration around the hole is determined by a finite-element method. The results are compared with experimental data and other analytical works. Parametric studies of effects of angle of inclination, plate thickness, and width are performed. The maximum stress concentration factor (SCF) obtained from the finite-element analysis is higher than experimental results, and this deviation increases with the increase of angle of skewness. The major reason for this difference is attributed to the shear-action between layers parallel to the plate surface which cannot be directly included in the two-dimensional elements. An empirical formula is derived which accounts for the shear-action and renders the finite-element predictions in line with experimentally observed data.

scholarly journals Validation of Welding Simulations Using Thermal Strains Measured with DIC

2011 ◽  
Vol 70 ◽  
pp. 129-134 ◽  
Author(s):  
Maarten De Strycker ◽  
Pascal Lava ◽  
Wim Van Paepegem ◽  
Luc Schueremans ◽  
Dimitri Debruyne
Keyword(s):  
Residual Stresses ◽  
Cross Section ◽  
Circular Cross Section ◽  
Welding Process ◽  
Weld Bead ◽  
Image Correlation ◽  
Steel Tubes ◽  
Element Analysis ◽  
Strain Evolution ◽  
The Cross

Residual stresses can affect the performance of steel tubes in many ways and as a result their magnitude and distribution is of particular interest to many applications. Residual stresses in cold-rolled steel tubes mainly originate from the rolling of a flat plate into a circular cross section (involving plastic deformations) and the weld bead that closes the cross section (involving non-uniform heating and cooling). Focus in this contribution is on the longitudinal weld bead that closes the cross section. To reveal the residual stresses in the tubes under consideration, a finite element analysis (FEA) of the welding step in the production process is made. The FEA of the welding process is validated with the temperature evolution of the thermal simulation and the strain evolution for the mechanical part of the analysis. Several methods for measuring the strain evolution are available and in this contribution it is investigated if the Digital Image Correlation (DIC) technique can record the strain evolution during welding. It is shown that the strain evolution obtained with DIC is in agreement with that found by electrical resistance strain gauges. The results of these experimental measuring methods are compared with numerical results from a FEA of the welding process.

Finite Element Analysis for the Collapse Accident of a 110kV Transmission Tower

2014 ◽  
Vol 986-987 ◽  
pp. 927-930
Author(s):  
Yi Zhu ◽  
Bo Li ◽  
Hao Wang ◽  
Kun Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Strong Wind ◽  
Transmission Tower ◽  
Element Analysis ◽  
Straight Line ◽  
The Finite Element Analysis

Put the finite element analysis of line tower coupling modeling to the collapse of a 110 kV line straight-line tower, study the effect of strong wind on transmission tower and wire. The results show that under the action of strong wind, the material specification selected by the part of the rods on the type of tower is lower, cross section is smaller, the principal material of tower will be instable and flexional under the compression, resulting in tower collapsed.

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