Reliability of thin-walled cylinder tests for elastic properties of anisotropic rocks

1996 ◽  
Vol 33 (6) ◽  
pp. 1008-1014 ◽  
Author(s):  
M L Talesnick
Keyword(s):  
Elastic Properties ◽  
Hollow Cylinder ◽  
Testing Procedure ◽  
Test Method ◽  
Material Parameters ◽  
Transverse Isotropic ◽  
Anisotropic Rocks ◽  
Hollow Cylinders ◽  
Thin Walled

Elastic properties of transverse isotropic rocks may be theoretically determined by subjecting a single hollow cylinder specimen to a set of two simple stress conditions. The reliability of the methodology is considered by testing both thin-walled hollow cylinders and thick-walled hollow cylinders. The results indicate that the testing procedure produces consistent material parameters, sample preparation does not seem to induce changes in the specimen behaviour, and that the assumptions implemented in the determination of the material parameters are reasonable. Key words: hollow cylinder, anisotropy, elasticity, test method.

Hoop-Stress Loading - A New Method of Determining the Tensile Strength of Rock

1972 ◽  
Vol 12 (03) ◽  
pp. 246-252 ◽  
Author(s):  
H. Reginald Hardy ◽  
Natesa I. Jayaraman
Keyword(s):  
Tensile Strength ◽  
Hoop Stress ◽  
Test Method ◽  
Experimental Results ◽  
Mining Operations ◽  
Test Technique ◽  
Rock Types ◽  
Hollow Cylinders ◽  
Strong Candidate

Abstract Although it is well known that rock commonly fails in tension under numerous field conditions, a satisfactory standard procedure for determination of the tensile strength of such materials has not as yet been established. With suitable precautions, direct-pull tests may be used; however, precise specimen preparation and extremely uniform and concentric loading must be utilized if meaningful results are to be obtained using this method. Recently, the authors completed a 3-year study in which a variety of methods for determining tensile strength were evaluated. One method, involving the hoop-stress loading of thick-walled hollow cylinders, was found to be particularly attractive. This paper describes the theory, apparatus, and test technique associated with this method. In evaluating this new technique a number of specimens of Barre granite, Lauders and Indiana limestone, and Berea and Tennessee sandstone were tested. Reproducibility for each rock type was fund to be excellent, with the percentage standard deviation ranging from a maximum of 10.9 percent for Lauders limestone down to 0.9 percent for Berea sandstone. Values of tensile strength determined from hoop-stress tests were found to correspond closely to those determined by direct pull, provided the former were analyzed in terms of pull, provided the former were analyzed in terms of an equation based on a suitable elastic-plastic analysis. Under these conditions the ratio of hoop-stress to direct-pull tensile strength values ranged from 0.86 to 1.10 for the five rocks tested. Although studies on additional rock types are required, it appears that the hoop-stress loading method would be a strong candidate as a standard test for determination of the tensile strength of rock. Introduction Although it is well known that tensile stresses play an important role in the behavior of underground play an important role in the behavior of underground openings associated with petroleum, natural gas and mining operations, suitable techniques for the determination of the tensile strength of rock are limited. A detailed study of the literature relating to the measurement of the tensile strength of rock has been presented by Jayaraman. This study indicated that, although rock mechanics literature includes numerous papers dealing with the measurement of the tensile strength of various rock types, relatively little attention has been focused on the development of meaningful techniques for the determination of this parameter. Experimental difficulties and poor results encountered in carrying out direct tensile tests have led a number of workers to investigate a variety of indirect methods. Unfortunately, many of these studies have been carried out on rocklike materials rather than on actual rocks. Furthermore, in many cases an insufficient number of tests have been conducted to evaluate accurately the test procedures employed. procedures employed. Recently the authors completed an extensive study in which a variety of methods for determining the tensile strength of rock were evaluated. During this investigation the apparent tensile strength of a number of rock types was determined using four different methods, namely:direct-pull of solid cylinders,diametric compression of solid-discs,diametric compression of hollow-discs, andhoop-stress loading of hollow cylinders. An outline of this study and details of the experimental results obtained have been presented in a recent paper. One test method, involving the hoop-stress loading of thick-walled hollow cylinders, was found to be particularly attractive. Based on the experimental results obtained to date, it appears that the hoop-stress method would be a strong candidate as a standard for determination of the tensile strength of rock. The present paper describes the theory, apparatus and test technique associated with this method. Tensile strength data are presented for five different rock types; two limestones, two sandstones and a granite. SPEJ P. 246

On the determination of the stress-strain curve of clay from the undrained plane-strain expansion of hollow cylinders: a long-forgotten method

1998 ◽  
Vol 35 (2) ◽  
pp. 360-363 ◽  
Author(s):  
V Silvestri
Keyword(s):  
Shear Stress ◽  
Plane Strain ◽  
Hollow Cylinder ◽  
Strain Curve ◽  
Outer Radius ◽  
Triaxial Tests ◽  
Inner Radius ◽  
Stress Curve ◽  
Hollow Cylinders

This paper presents the method to obtain the shear stress curve of clay from the undrained plane-strain expansion of hollow cylinder triaxial tests. No prior knowledge of the constitutive properties of the material is required. The theory also indicates that when the outer radius of the cylinder is very large compared with the inner radius, the equation used to interpret pressuremeter tests in clay is recovered.Key words: hollow cylinder, expansion tests, clays, plane strain, undrained condition, shear stress curve.

Tire Treadwear — A Comprehensive Evaluation of the Factors: Generic Type, Aspect Ratio, Tread Pattern, and Tread Composition Part I: Introduction and Details on the Organization of the Program

1986 ◽  
Vol 14 (4) ◽  
pp. 201-218 ◽  
Author(s):  
A. G. Veith
Keyword(s):  
Aspect Ratio ◽  
Comprehensive Evaluation ◽  
Test Method ◽  
Interactive Effects ◽  
Data Analyses ◽  
Main Effect ◽  
Systematic Determination ◽  
Relationship Of ◽  
The Relationship

Abstract This four-part series of papers addresses the problem of systematic determination of the influence of several tire factors on tire treadwear. Both the main effect of each factor and some of their interactive effects are included. The program was also structured to evaluate the influence of some external-to-tire conditions on the relationship of tire factors to treadwear. Part I describes the experimental design used to evaluate the effects on treadwear of generic tire type, aspect ratio, tread pattern (groove or void level), type of pattern (straight rib or block), and tread compound. Construction procedures and precautions used to obtain a valid and functional test method are included. Two guiding principles to be used in the data analyses of Parts II and III are discussed. These are the fractional groove and void concept, to characterize tread pattern geometry, and a demonstration of the equivalence of wear rate for identical compounds on whole tread or multi-section tread tires.

Sign in / Sign up

Export Citation Format

Share Document