Effect of Material Properties on the Strain to Failure of Thick-Walled Cylinders Subjected to Internal Pressure

1994 ◽  
Vol 116 (2) ◽  
pp. 96-104 ◽  
Author(s):  
D. P. Roach ◽  
T. G. Priddy
Keyword(s):  
Internal Pressure ◽  
Material Properties ◽  
Maximum Pressure ◽  
Plastic Response ◽  
Empirical Formulas ◽  
Stress Strain Relation ◽  
Simple Tension ◽  
Bursting Pressures ◽  
Versus Strain

The determination of the fully plastic response and pressure limit of a pressure vessel is of considerable importance in design, especially in autofrettage considerations. This paper presents the results of an experimental study which measured the maximum internal pressure which can be applied to thick-walled cylindrical vessels. Both aluminum and steel, with material properties ranging from ductile to brittle, were tested at stress levels through plastic and strain hardening ranges to fracture. From these tests, the pressure-expansion and through-thickness yielding characteristics were determined for these specimens. It is shown that a strain-to-failure criterion, based on the triaxiality of stress in the critical region, can be used to predict the complete pressure versus strain relations and maximum pressure for these cylinders. A simple tension-true stress-strain relation of the material is employed to analytically predict the response of the cylinder into the plastic regime. Finally, simplified theoretical and empirical formulas for bursting pressures are checked against the experimental results.

Determination of non-linear, large, equal biaxial stresses and strains in thin elastomeric sheets by bubble inflation

2002 ◽  
Vol 216 (4) ◽  
pp. 233-243 ◽  
Author(s):  
R Johannknecht ◽  
G Clauss ◽  
S Jerrams
Keyword(s):  
Internal Pressure ◽  
Experimental Method ◽  
Material Properties ◽  
Local Stress ◽  
Measuring System ◽  
Stress And Strain ◽  
Material Models ◽  
Biaxial Deformation ◽  
On Line

This paper presents a method for investigating the axisymmetric bubble inflation of elastomers by an optical measuring system and determining local stress and strain properties in biaxial deformation. In particular, the local stretch ratios on the bubble shell are evaluated by an element grid [1,2]. Both the pattern and the bubble contour are observed optically on-line during a continuous inflation process. The relations between internal pressure, bubble height and local shell stresses and strains are analysed. Additionally, free and tube-guided inflation using hydraulic and pneumatic pressure systems are compared. As stresses toward the pole of the bubble gradually increase during the inflation process, the experimental method permits an investigation into material properties at high equibiaxial loadings and the determination of constants for different material models. The conclusion of this investigation is that simple assumptions that relate local stress and strain levels to the bubble inflation height cannot be made.

Strength of Thick-Walled Pressure Vessels for Materials With Directional Properties

1962 ◽  
Vol 84 (2) ◽  
pp. 197-202
Author(s):  
A. E. Dapprich ◽  
Joseph Marin ◽  
Tu-Lung Weng
Keyword(s):  
Tensile Stress ◽  
Pressure Vessel ◽  
Anisotropic Material ◽  
Pressure Vessels ◽  
Maximum Pressure ◽  
Closed Solution ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Cylindrical Pressure Vessel

This paper develops a theory for the determination of the plastic pressure-deformation relation in a thick-walled cylindrical pressure vessel subjected to internal pressure and made of an anisotropic material. In this theory, large or finite strains are considered and a closed solution is found for the pressure-strain relation based on a modified log-log tensile stress-strain relation. Theory is also developed for predicting the maximum pressure which the vessel can withstand.

Determination of Charge Coefficient of Piezoelectric Films Using a Combined Finite Element Model and Dynamic Loading Technique

2020 ◽  
Vol 835 ◽  
pp. 229-242
Author(s):  
Oboso P. Bernard ◽  
Nagih M. Shaalan ◽  
Mohab Hossam ◽  
Mohsen A. Hassan
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Material Properties ◽  
Accurate Determination ◽  
Substrate Material ◽  
Experimental Results ◽  
Piezoelectric Composite ◽  
Piezoelectric Film ◽  
Piezoelectric Charge

Accurate determination of piezoelectric properties such as piezoelectric charge coefficients (d33) is an essential step in the design process of sensors and actuators using piezoelectric effect. In this study, a cost-effective and accurate method based on dynamic loading technique was proposed to determine the piezoelectric charge coefficient d33. Finite element analysis (FEA) model was developed in order to estimate d33 and validate the obtained values with experimental results. The experiment was conducted on a piezoelectric disc with a known d33 value. The effect of measuring boundary conditions, substrate material properties and specimen geometry on measured d33 value were conducted. The experimental results reveal that the determined d33 coefficient by this technique is accurate as it falls within the manufactures tolerance specifications of PZT-5A piezoelectric film d33. Further, obtained simulation results on fibre reinforced and particle reinforced piezoelectric composite were found to be similar to those that have been obtained using more advanced techniques. FE-results showed that the measured d33 coefficients depend on measuring boundary condition, piezoelectric film thickness, and substrate material properties. This method was proved to be suitable for determination of d33 coefficient effectively for piezoelectric samples of any arbitrary geometry without compromising on the accuracy of measured d33.

Deformation Behavior Prediction of X80 Steel Line Pipe and Implication on High Strain Pipe Specification

2008 ◽  
Author(s):  
Hongyuan Chen ◽  
Lingkang Ji ◽  
Shaotao Gong ◽  
Huilin Gao
Keyword(s):  
Internal Pressure ◽  
Material Properties ◽  
High Strain ◽  
Behavior Prediction ◽  
Buckling Mode ◽  
Line Pipe ◽  
Geometric Imperfection ◽  
China National Petroleum Corporation ◽  
Scale Test ◽  
Pipe Size

The use of strain based design in pipeline technology has been widely discussed during the last decade for pipelines in harsh environment. In such cases pipelines should be designed based on strain criterion. Strain based design poses a number of challenges, particularly on pipe size and material properties. This paper presents preliminary studies on prediction of buckling strain and buckling mode for X80 high-strain line pipe by finite element methods based on full-scale test. The effects of several parameters such as internal pressure, material properties pipe size and geometric imperfection, were investigated to predict the critical strain for 48″ diameter line pipe under compression and pure bending with 12MPa internal pressure. Material parameters of a specification for high strain line pipe were analyzed to promote its application in the 2nd West-East pipeline of China National Petroleum Corporation.

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