A Benchmark Study of Bending Limit Load Finite Element Analysis for Locally Wall Thinned Pipes

2013 ◽  
Author(s):  
Phuong H. Hoang ◽  
Bostjan Bezensek ◽  
Howard J. Rathbun
Keyword(s):  
Finite Element ◽  
Limit Load ◽  
Benchmark Problems ◽  
Square Root ◽  
Bending Moments ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Benchmark Analysis ◽  
Benchmark Study ◽  
Computer Codes

Finite element analyses (FEA) have been used to study the effects of multi-axial loadings on bending limit load of local wall thinned pipes. It has been shown by investigators that torsion can be combined with bending moments using SRSS (Square Root of the Sum of the Squares) method for planar flaws with a limited axial extent. The treatment of torsion for non-planar flaws, which exceed the axial extent limit, will be a subject for future investigations. Since the reported FEA results are for various pipe sizes, flaw shapes with different mesh sizes, element types and computer codes, a set of benchmark problems was proposed and analyzed by participating investigators. The benchmark analysis results are presented in this paper.

Simplified Limit Load Determination Using the mα-Tangent Method

2008 ◽  
Author(s):  
R. Seshadri ◽  
M. M. Hossain
Keyword(s):  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Limit Loads ◽  
Linear Elastic ◽  
Tangent Method ◽  
Mechanical Components

Limit load determination of mechanical components and structures by the mα-tangent method is proposed herein. The proposed technique is a simplified method that enables rapid determination of limit loads for a general class of mechanical components and structures. The method makes use of statically admissible stress field based on a linear elastic finite element analysis to estimate the limit loads. The method is applied to a number of mechanical component configurations and the results compare well with those obtained by the corresponding elastic-plastic finite element analyses results.

Full Scale Burst Test and Finite Element Analysis on Corroded Gas Pipeline

2002 ◽  
Author(s):  
Woo-Sik Kim ◽  
Young-Pyo Kim ◽  
Young-Tai Kho ◽  
Jae-Boong Choi
Keyword(s):  
Finite Element ◽  
Limit Load ◽  
Failure Criteria ◽  
Finite Element Analyses ◽  
Gas Pipelines ◽  
Element Analysis ◽  
Burst Test ◽  
Element Simulation ◽  
X65 Steel ◽  
Corrosion Defects

Pipelines have the highest capacity and are the safest and least environmentally disruptive way for gas or oil transmission. Recently, failures due to corrosion defects became of major concern in maintaining pipeline integrity. A number of solutions have been developed for the assessment of remaining strength of corroded pipelines. However, these solutions are known to be dependent on material properties and pipeline geometries. In this paper, a Fitness-For-Purpose (FFP) type limit load solution for corroded gas pipelines made of X65 steel is proposed based on experimental results and finite element analyses. For this purpose, a series of burst tests with various types of corrosion defects was performed. Finite element simulation was carried out on burst test to derive failure criteria. And then, a series of finite element analyses were performed to obtain a limit load solution for a single corrosion defect on the basis of burst test simulation. As a result, an FFP type limit load solution for corroded X65 gas pipelines was proposed.

Simplified Limit Load Determination Using the mα-Tangent Method

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
R. Seshadri ◽  
M. M. Hossain
Keyword(s):  
Finite Element ◽  
Rapid Determination ◽  
Limit Load ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Limit Loads ◽  
Linear Elastic ◽  
Tangent Method ◽  
Mechanical Components

Limit load determination of mechanical components and structures by the mα-tangent method is proposed herein. The proposed technique is a simplified method that enables rapid determination of limit loads for a general class of mechanical components and structures. The method makes use of statically admissible stress field based on a linear elastic finite element analysis to estimate the limit loads. The method is applied to a number of mechanical component configurations and the results compare well with those obtained by the corresponding elastic-plastic finite element analyses results.

Buckling characteristics of cut-out borne composite stiffened hyperbolic paraboloid shell panel

2021 ◽  
pp. 146442072110058
Author(s):  
Sarmila Sahoo
Keyword(s):  
Finite Element ◽  
Orientation Angle ◽  
Buckling Load ◽  
Benchmark Problems ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Load Effect ◽  
Global Buckling ◽  
Fiber Orientation Angle ◽  
Shell Panel

The present study investigates buckling characteristics of cut-out borne stiffened hyperbolic paraboloid shell panel made of laminated composites using finite element analysis to evaluate the governing differential equations of global buckling of the structure. The finite element code is validated by solving benchmark problems from literature. Different parametric variations are studied to find the optimum panel buckling load. Laminations, boundary conditions, depth of stiffener and arrangement of stiffeners are found to influence the panel buckling load. Effect of different parameters like cut-out size, shell width to thickness ratio, degree of orthotropy and fiber orientation angle of the composite layers on buckling load are also studied. Parametric and comparative studies are conducted to analyze the buckling strength of composite hyperbolic paraboloid shell panel with cut-out.

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.

Investigation on endurance evaluation of a portal crane: experimental, theoretical and finite element analysis

2020 ◽  
Vol 62 (4) ◽  
pp. 357-364
Author(s):  
Yusuf Aytaç Onur ◽  
Hakan Gelen
Keyword(s):  
Finite Element ◽  
Critical Points ◽  
Maximum Stress ◽  
Strain Gages ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Element Simulation ◽  
Main Girder ◽  
Stressed Component ◽  
Portal Crane

Abstract In this study, the stress on portal crane components at various payloads has been investigated theoretically, numerically and experimentally. The portal crane was computer-aided modeled and finite element analyses were performed so that the most stressed points at the each trolley position investigated on the main girder could be determined. In addition, the critical points were marked on the portal crane, and strain gages were attached to the those critical points so that stress values could be experimentally determined. The safety factor values at different payloads were determined by using finite element simulation. Results indicate that the most stressed component in the examined portal crane is the main girder. Experimental results indicate that the maximum stress value on the main girder is 3.05 times greater than the support legs and 8.99 times larger than the rail.

scholarly journals Effect of Ovality in Inlet Pigtail Pipe Bends Under Combined Internal Pressure and In-Plane Bending for Ni-Fe-Cr B407 Material

2017 ◽  
Vol 62 (3) ◽  
pp. 1881-1887
Author(s):  
P. Ramaswami ◽  
P. Senthil Velmurugan ◽  
R. Rajasekar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Internal Pressure ◽  
Limit Load ◽  
Outer Radius ◽  
Factor H ◽  
Geometrical Shape ◽  
Element Analysis ◽  
Pipe Bend ◽  
Plane Bending

Abstract The present paper makes an attempt to depict the effect of ovality in the inlet pigtail pipe bend of a reformer under combined internal pressure and in-plane bending. Finite element analysis (FEA) and experiments have been used. An incoloy Ni-Fe-Cr B407 alloy material was considered for study and assumed to be elastic-perfectly plastic in behavior. The design of pipe bend is based on ASME B31.3 standard and during manufacturing process, it is challenging to avoid thickening on the inner radius and thinning on the outer radius of pipe bend. This geometrical shape imperfection is known as ovality and its effect needs investigation which is considered for the study. The finite element analysis (ANSYS-workbench) results showed that ovality affects the load carrying capacity of the pipe bend and it was varying with bend factor (h). By data fitting of finite element results, an empirical formula for the limit load of inlet pigtail pipe bend with ovality has been proposed, which is validated by experiments.

J-Integral Analysis of Surface Cracks in Round Bars under Bending Moments

2011 ◽  
Vol 52-54 ◽  
pp. 43-48 ◽  
Author(s):  
Al Emran Ismail ◽  
Ahmad Kamal Ariffin ◽  
Shahrum Abdullah ◽  
Mariyam Jameelah Ghazali ◽  
Ruslizam Daud
Keyword(s):  
Finite Element ◽  
Crack Depth ◽  
Crack Tip ◽  
Bending Moment ◽  
Limit Load ◽  
Fe Model ◽  
Surface Cracks ◽  
Element Analysis ◽  
Reference Stress ◽  
Proposed Model

This paper presents a non-linear numerical investigation of surface cracks in round bars under bending moment by using ANSYS finite element analysis (FEA). Due to the symmetrical analysis, only quarter finite element (FE) model was constructed and special attention was given at the crack tip of the cracks. The surface cracks were characterized by the dimensionless crack aspect ratio, a/b = 0.6, 0.8, 1.0 and 1.2, while the dimensionless relative crack depth, a/D = 0.1, 0.2 and 0.3. The square-root singularity of stresses and strains was modeled by shifting the mid-point nodes to the quarter-point locations close to the crack tip. The proposed model was validated with the existing model before any further analysis. The elastic-plastic analysis under remotely applied bending moment was assumed to follow the Ramberg-Osgood relation with n = 5 and 10. J values were determined for all positions along the crack front and then, the limit load was predicted using the J values obtained from FEA through the reference stress method.

scholarly journals Simulating sauropod manus-only trackway formation using finite-element analysis

2010 ◽  
Vol 7 (1) ◽  
pp. 142-145 ◽  
Author(s):  
P. L. Falkingham ◽  
K. T. Bates ◽  
L. Margetts ◽  
P. L. Manning
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surface Area ◽  
Fossil Record ◽  
Temporal Correlation ◽  
Finite Element Analyses ◽  
Centre Of Mass ◽  
Element Analysis ◽  
Mass Distributions ◽  
Track Formation

The occurrence of sauropod manus-only trackways in the fossil record is poorly understood, limiting their potential for understanding locomotor mechanics and behaviour. To elucidate possible causative mechanisms for these traces, finite-element analyses were conducted to model the indentation of substrate by the feet of Diplodocus and Brachiosaurus . Loading was accomplished by applying mass, centre of mass and foot surface area predictions to a range of substrates to model track formation. Experimental results show that when pressure differs between manus and pes, as determined by the distribution of weight and size of respective autopodia, there is a range of substrate shear strengths for which only the manus (or pes) produce enough pressure to deform the substrate, generating a track. If existing reconstructions of sauropod feet and mass distributions are correct, then different taxa will produce either manus- or pes-only trackways in specific substrates. As a result of this work, it is predicted that the occurrence of manus- or pes-only trackways may show geo-temporal correlation with the occurrence of body fossils of specific taxa.

Large elastic deformation of micromorphic shells. Part II. Isogeometric analysis

2019 ◽  
Vol 24 (12) ◽  
pp. 3753-3778 ◽  
Author(s):  
Amir Norouzzadeh ◽  
Reza Ansari ◽  
Mansour Darvizeh
Keyword(s):  
Finite Element ◽  
Elastic Deformation ◽  
Isogeometric Analysis ◽  
Constitutive Relations ◽  
Kinematic Model ◽  
Benchmark Problems ◽  
Element Analysis ◽  
Deformation Problem ◽  
Macro Scale ◽  
Large Elastic Deformation

In Part I of this study, a variational formulation was presented for the large elastic deformation problem of micromorphic shells. Using the novel matrix-vector format presented for the kinematic model, constitutive relations, and energy functions, an isogeometric analysis (IGA)-based solution strategy is developed, which appropriately estimates the macro- and micro-deformation field components. Due to the capability of constructing exact geometries and the powerful mesh refinement tools, IGA can be successfully applied to solve the equilibrium equations with dominant nonlinear terms. It is known that different types of locking phenomena take place in the conventional finite element analysis of thin shells based on low-order elements. Non-standard finite element models with mixed interpolation schemes and additional degrees of freedom (DOFs) or the ones used the high-order Lagrangian shell elements which require high computational costs, are the available solutions to tackle locking issues. The present 16-DOFs IGA is found to be efficient because of possessing a good rate of convergence and providing locking-free stable responses for micromorphic shells. Such a conclusion is found from several comparative studies with available data in the well-known macro-scale benchmark problems based on the classical elasticity as well as the corresponding numerical examples studied in nano-scale beam-, plate-, cylindrical shell- and spherical shell-type structures on the basis of the micromorphic continuum theory.

Sign in / Sign up

Export Citation Format

Share Document