Maximum Stress at Intersecting Bores of Pressurized Blocks

1994 ◽  
Author(s):  
Ajay Garg
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Tensile Stress ◽  
Element Model ◽  
Maximum Tensile Stress ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Empirical Methods ◽  
Element Analysis ◽  
Matched Design

Abstract In high pressure applications, rectangular blocks of steel are used instead of cylinders as pressure vessels. Bores are drilled in these blocks for fluid flow. Intersecting bores with axes normal to each other and of almost equal diameters, produce stresses which can be many times higher than the internal pressure. Experimental results for the magnitude of maximum tensile stress along the intersection contour were available. A parametric finite element model simulated the experimental set up, followed by correlation between finite element analysis and experimental results. Finally, empirical methods are applied to generate models for the maximum tensile stress σ11 at cross bores of open and close ended blocks. Results from finite element analysis and empirical methods are further matched. Design optimization of cross bores is discussed.

A Study on Bursting Pressure of Thin-Walled Cylinders

2008 ◽  
Author(s):  
Yang-Chun Deng ◽  
Gang Chen ◽  
Liang Sun ◽  
Tong Xu
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Failure Criterion ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Bursting Pressure ◽  
Element Analysis ◽  
Instability Strain ◽  
Thin Walled

In this paper, we investigated the bursting pressure of thin-walled cylinders. Considering the strain hardening behavior of materials and the geometry deformation of pressure vessels, we derived the instability strain of thin-walled cylinders with a Swift-type stress-strain relationship, and used it as a failure criterion. Consequently, the instability stress was obtained and used to determine the maximum load-bearing capacity of thin-walled cylinders, that is, bursting pressure. The analytical solutions were compared with finite element analysis and bursting experimental results on different size thin-walled cylindrical pressure vessels manufactured from three different materials. It was turned out that it is reasonable to adopt instability strain as a failure criterion and use instability pressure as burst pressure. In the finite element analysis, the material parameters used were from raw experimental data or fitted values of experimental data. For both cases, finite element predications on instability strain and bursting pressure gave around the same values, close to experimental results. Therefore, based on finite element analyses, the instability strain and bursting pressure can be calculated by using true stress-strain curves directly measured from experiments, without the need to assume any specific material type.

Stress Classification Plane and Its Application in Finite Element Analysis

2009 ◽  
Author(s):  
Jianfeng Yang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cross Section ◽  
Element Model ◽  
Pressure Vessels ◽  
Design Code ◽  
Entire Cross Section ◽  
Element Analysis ◽  
Component Design ◽  
Stress Classification

The stresses within pressure vessels and internals, etc. are categorized into membrane, bending, and peak stresses in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code, as well as many other design codes of different countries. The total stress results calculated from a finite element analysis, which is the most commonly utilized tool in the component design, have to be classified into these categories to be compared to the design code criteria. The stress classification line (SCL) method has been developed to linearize the stresses along a line cutting through the thickness of the component. However, the SCL method tends to overestimate or underestimate the linearized stresses if the stress distribution of the cross-section is not axisymmetric. Since the design code criteria are given over a cross-section, this article proposes a stress classification plane (SCP) method in stress linearization. An SCP is defined as a cross-section that cuts through a solid 3-D finite element model. The element nodes do not need to lie on the SCP. The stresses are linearized over the entire cross-section that defines the SCP. Therefore, the linearized stresses obtained using this method are consistent with the design code definitions. The SCP approach provides an accurate and convenient tool when comparing the finite element results to the Code criteria during the component design and analysis process. As an example, the applications of the SCP method using ANSYS® are also given in this article.

scholarly journals Analysis of the Static Behavior of a Single Tree on a Finite Element Model

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1284
Author(s):  
Ľuboš Moravčík ◽  
Radko Vincúr ◽  
Zdenka Rózová
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Analysis ◽  
Tensile Stress ◽  
Finite Element Model ◽  
Cross Section ◽  
Element Model ◽  
Tree Structure ◽  
Element Analysis ◽  
Whole Tree

This work deals with the innovated complex process of tree risk assessment, from precise geometrical tree shape acquisition to building and analyzing a finite element model under specified load. The acquisition of the 3D geometry of the tree was performed by means of terrestrial laser scanning. Obtained point cloud was optimized and additionally converted to a 3D CAD model, representing the bearing skeleton compound of trunk and main branches. For structural analysis purposes, a finite element model (FEM) was built in the form of beam structure fixed to the ground. Particular beams were defined by geometry, material properties of wood, and cross sections. An acoustic tomography was applied for determination of the precise cross section on investigated locations of an analysis model. Finite element analysis performed on the computational model shows the bearing capacity and deformations of the whole tree structure caused by combinations of load cases like self-weight and static equivalent of wind load. The results of the structural analysis called attention to potentially dangerous places within the tree structure with extreme node displacements or tensile stresses on beams. Thus, we observed a maximal horizontal displacement of 280.4 mm in node N34 and dangerous tensile stress in node N26, where it reaches +23.6 MPa. After filtering some beams with an abnormal cross section geometry, the finite element analysis of the whole tree structure showed the highest tensile stress of +8.8 MPa and highest compressive stress of −8.9 MPa. The suggested method can be applied generally for the prediction of potentially risky tree suspected of breakage and especially for monumental trees, where the presented method can be mostly applicable.

Finite Element Analysis of Fretting Stresses

1997 ◽  
Vol 119 (4) ◽  
pp. 797-801 ◽  
Author(s):  
P. A. McVeigh ◽  
T. N. Farris
Keyword(s):  
Finite Element ◽  
Tensile Stress ◽  
Element Model ◽  
Fretting Fatigue ◽  
Maximum Tensile Stress ◽  
Multiaxial Fatigue ◽  
Fretting Wear ◽  
Symmetric Distribution ◽  
Element Analysis ◽  
Riveted Joints

Clamped contacts subjected to vibratory loading undergo cyclic relative tangential motion or micro-slip near the edges of contact. This cyclic micro-slip, known as fretting, leads to removal of material through a mechanism known as fretting wear and formation and growth of cracks through a mechanism known as fretting fatigue. In aircraft, fretting fatigue occurs at the rivet/hole interface leading to multisite damage which is a potential failure mechanism for aging aircraft. A finite element model of a current fretting fatigue experiment aimed at characterizing fretting in riveted joints is detailed. A non-symmetric bulk tension is applied to the specimen in addition to the loads transferred from the fretting pad. The model is verified through comparison to the Mindlin solution for a reduced loading configuration, in which the bulk tension is not applied. Results from the model with the bulk tension show that the distribution of micro-slip in the contact is not symmetric and that for some loads reversed micro-slip occurs. Finite element results are given for the effects that four different sets of loading parameters have on the maximum tensile stress induced by fretting at the trailing edge of contact. It can be shown using multiaxial fatigue theory that this stress controls fretting fatigue crack formation. This maximum tensile stress is compared to that of the Mindlin solution for a symmetric distribution of micro-slip. This stress is also compared to that of a variation based on the Mindlin solution for the cases with a non-symmetric distribution of micro-slip. It is concluded that the solution based on the Mindlin variation and the full finite element solution lead to similar predictions of the maximum tensile stress, even when the shear traction solutions differ significantly.

Development of Design Rules for Nozzles in Pressure Vessels for the ASME B&PV Code, Section VIII, Division 2

2011 ◽  
Author(s):  
Zhenning Cao ◽  
Les Bildy ◽  
David A. Osage ◽  
J. C. Sowinski
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessels ◽  
Experimental Results ◽  
Working Pressure ◽  
Element Analysis ◽  
Design Rules ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

The theory behind the pressure-area method that is incorporated in the ASME B&PV Code, Section VIII-2 is presented in this paper. Background and insight to the nozzle rules of ASME B&PV Code, Section VIII, Division 2, Part 4, paragraph 4.5 are also provided. Recommendations for modifying the current nozzles rules, those published in ASME B&PV Code, Section VIII, Division 2, 2010 Edition, is given based on continuing research and development efforts. A comparison between experimental results, results derived from detailed finite element analysis (FEA), the rules prior to the VIII-2 Rewrite (2004 Edition), and the rules in VIII-2 are provided in terms of a design margin and permissible maximum allowable working pressure (MAWP) computed with the design rules. A complete description of the theory including a commentary and comparison to experimental results is provided in WRC529 [1].

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Tire Cornering Simulation Using an Explicit Finite Element Analysis Code

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Test System ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Element Method

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.

scholarly journals Comparison of Tooth- and Bone-Borne Appliances on the Stress Distributions and Displacement Patterns in the Facial Skeleton in Surgically Assisted Rapid Maxillary Expansion—A Finite Element Analysis (FEA) Study

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1152
Author(s):  
Rafał Nowak ◽  
Anna Olejnik ◽  
Hanna Gerber ◽  
Roman Frątczak ◽  
Ewa Zawiślak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Rapid Maxillary Expansion ◽  
Stress Distributions ◽  
Maxillary Expansion ◽  
Facial Skeleton ◽  
Element Analysis ◽  
Maxillary Constriction

The aim of this study was to compare the reduced stresses according to Huber’s hypothesis and the displacement pattern in the region of the facial skeleton using a tooth- or bone-borne appliance in surgically assisted rapid maxillary expansion (SARME). In the current literature, the lack of updated reports about biomechanical effects in bone-borne appliances used in SARME is noticeable. Finite element analysis (FEA) was used for this study. Six facial skeleton models were created, five with various variants of osteotomy and one without osteotomy. Two different appliances for maxillary expansion were used for each model. The three-dimensional (3D) model of the facial skeleton was created on the basis of spiral computed tomography (CT) scans of a 32-year-old patient with maxillary constriction. The finite element model was built using ANSYS 15.0 software, in which the computations were carried out. Stress distributions and displacement values along the 3D axes were found for each osteotomy variant with the expansion of the tooth- and the bone-borne devices at a level of 0.5 mm. The investigation showed that in the case of a full osteotomy of the maxilla, as described by Bell and Epker in 1976, the method of fixing the appliance for maxillary expansion had no impact on the distribution of the reduced stresses according to Huber’s hypothesis in the facial skeleton. In the case of the bone-borne appliance, the load on the teeth, which may lead to periodontal and orthodontic complications, was eliminated. In the case of a full osteotomy of the maxilla, displacements in the buccolingual direction for all the variables of the bone-borne appliance were slightly bigger than for the tooth-borne appliance.

Finite Element Analysis and Optimization of Long-Span Gantry NC Machining Center Structure

2011 ◽  
Vol 346 ◽  
pp. 379-384
Author(s):  
Shu Bo Xu ◽  
Yang Xi ◽  
Cai Nian Jing ◽  
Ke Ke Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Design Method ◽  
Dynamic Performance ◽  
Plate Thickness ◽  
Element Model ◽  
Wall Structure ◽  
Characteristic Analysis ◽  
Element Analysis ◽  
Dynamic Performance Analysis

The use of finite element theory and modal analysis theory, the structure of the machine static and dynamic performance analysis and prediction using optimal design method for optimization, the new machine to improve job performance, improve processing accuracy, shorten the development cycle and enhance the competitiveness of products is very important. Selected for three-dimensional CAD modeling software-UG NX4.0 and finite element analysis software-ANSYS to set up the structure of the beam finite element model, and then post on the overall structure of the static and dynamic characteristic analysis, on the basis of optimized static and dynamic performance is more superior double wall structure of the beam. And by changing the wall thickness and the thickness of the inner wall, as well as the reinforcement plate thickness overall sensitivity analysis shows that changes in these three parameters on the dynamic characteristics of post impact. Application of topology optimization methods, determine the optimal structure of the beam ultimately.

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