scholarly journals Modeling for Distribution of Compressive Stress from Loading Platens in Diametrical Compression Test

2018 ◽  
Vol 250 ◽  
pp. 01009 ◽  
Author(s):  
Yukari Higashi ◽  
Shinnosuke Yoshinaga ◽  
Rini Asnida Abdullah ◽  
Takashi Tsutsumi
Keyword(s):  
Tensile Strength ◽  
Stress Distribution ◽  
Compressive Stress ◽  
Compression Test ◽  
Contact Area ◽  
Stress Function ◽  
Fourier Expansion ◽  
Complex Stress ◽  
Concentrated Loading ◽  
Indirect Tests

Diametrical Compression test is one of indirect tests to investigate the tensile strength of brittle materials. This test is spread because of easiness to perform. However, results from this test are not stable. Traditionally, calculations for this test are performed under a pair of opposite concentrated loading on the diameter of specimen. However, contact areas appear just before fracture of specimen in the fact and the stress distribution from loading platens is not obvious. It seems be one of reasons why the result from this test is not stable. In this study, the attempt to establish the modeling for distribution on loading platens in the diametrical compression test is shown. The aim of this modeling is to calculate stresses and displacement of specimen using complex stress function by Lekhnitskii. Therefore, this model is expanded in Fourier expansion. Accuracy of calculation using Fourier expansion depends on the number of terms. Therefore, the influence of contact area and number of terms to accuracy is also discussed.

scholarly journals Stress Distribution in Specimen for Diametrical Compression Test under Some Boundary Conditions

2018 ◽  
Vol 250 ◽  
pp. 01010
Author(s):  
Shinnosuke Yoshinaga ◽  
Yukari Higashi ◽  
Rini Asnida Abdullah ◽  
Takashi Tsutsumi
Keyword(s):  
Tensile Strength ◽  
Stress Distribution ◽  
Compression Test ◽  
Contact Area ◽  
Stress Distributions ◽  
Uniform Loading ◽  
Concentrated Load ◽  
Analytical Result ◽  
Indirect Tests ◽  
Theoretical Results

Diametrical Compression test is one of indirect tests to investigate the tensile strength of brittle materials. This test is spread because of easiness to perform. However, results from this test are not stable. Traditionally, calculations for diametrical compression test are performed under a pair of opposite concentrated load on the diameter of specimen. In the fact, contact areas are appears just before fracture of specimen and the stress distribution from loading platens is not obvious. It seems one of reasons why the result from this test is not stable. Several stress distributions between contact area and specimen have been proposed and stresses and strains have been calculated as theoretical results or analytical result in previous studies. In this study, the stress distribution that consists of uniform loading and cosine curve shaped loading is proposed and used for theoretical solution. Furthermore, results from this study are compared with results from previous studies.

The state of stress near the singularities created by a plane punch

1978 ◽  
Vol 13 (4) ◽  
pp. 231-236 ◽  
Author(s):  
N P Andrianopoulos ◽  
P S Theocaris
Keyword(s):  
Stress Distribution ◽  
Half Plane ◽  
Taylor Series ◽  
Stress Function ◽  
Complex Stress ◽  
The State ◽  
Singular Points ◽  
State Of Stress ◽  
Contact Surfaces ◽  
Complex Stress Function

An attempt is made to obtain photoelastically the stress distribution in the near vicinity of singular points, when a punch is indenting an elastic half-plane. The punch is to be assumed flat and rough so that friction is developed between the contact surfaces. By expanding the complex stress function into a Taylor series, an extrapolation law is obtained, which allows the calculation of stresses at the vicinity of the singular points by means of photoelastic measurements at positions remote from these points. The error limits of this technique are defined and, finally, a relation between the order of singularity and the parameters of the photoelastic pattern is established.

Size Effect on Mechanical Properties of LVL

2014 ◽  
Vol 887-888 ◽  
pp. 824-829
Author(s):  
Qing Fang Lv ◽  
Ji Hong Qin ◽  
Ran Zhu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Size Effect ◽  
Tensile Test ◽  
Compression Test ◽  
Test Results ◽  
Laminated Veneer Lumber ◽  
Object Of Study ◽  
The Relationship

Laminated veneer lumber is taken as an object of study, and use LVL specimens of different sizes for compression test and tensile test. The goal of the experiment is to investigate the size effect on compressive strength and tensile strength as well as the influence of the secondary glued laminated face, which appears in the secondary molding processes. The results show that both compressive strength and tensile strength have the size effect apparently and the existence of the secondary glued laminated face lower the compressive strength of LVL specimens. Afterwards, the relationship between compressive strength and volume along with tensile strength and area are obtained by the test results.

scholarly journals Studies on the Tensile Strength of Dental Amalgams by the Application of Diametral Compression Test

1970 ◽  
Vol 12 (1) ◽  
pp. 9-24
Author(s):  
Kazuo NAGAI ◽  
Masayoshi OHASHI ◽  
Hiroyoshi HABU ◽  
Masahiro UEMURA ◽  
Fujio KORENAGA ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Compression Test ◽  
Diametral Compression ◽  
Dental Amalgams ◽  
Diametral Compression Test

Adhesion of Wax Droplets to Porous Substrates

2012 ◽  
Author(s):  
Shima Dadvar ◽  
Sanjeev Chandra ◽  
Nasser Ashgriz ◽  
Stephan Drappel
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Impact Velocity ◽  
Analytical Model ◽  
Contact Area ◽  
Initial Temperature ◽  
Simple Analytical Model ◽  
Porous Polyethylene ◽  
Porous Surfaces ◽  
Strength Of Adhesion

The adhesion of solid wax ink droplets to porous polyethylene and Teflon substrates was studied experimentally. Wax droplets with a diameter of 3 mm and an initial temperature of 110°C were dropped onto test surfaces from heights varying from 20–50 mm. The Teflon surfaces had holes drilled in them to create idealized porous surfaces while the porous polyethylene sheets had mean pore sizes of either 35 or 70 μm. The force required to remove the wax splats from the substrates was measured by a pull test. The detachment force increased with droplet impact velocity. A simple analytical model is proposed to predict the force attaching the wax splat to the surface: it has an adhesive component, calculated by multiplying the contact area between the splat and substrate by the strength of adhesion; and a cohesive component, calculated by multiplying the area of the pores into which wax penetrates by the ultimate tensile strength of wax. Predictions from the model agreed reasonably well with measurements.

Analysis of Deep Beams

1951 ◽  
Vol 18 (2) ◽  
pp. 163-172
Author(s):  
H. D. Conway ◽  
L. Chow ◽  
G. W. Morgan
Keyword(s):  
Exact Solution ◽  
Approximate Solution ◽  
Stress Distribution ◽  
Finite Difference ◽  
Boundary Conditions ◽  
Normal Stress ◽  
Stress Function ◽  
Beam Theory ◽  
Deep Beam ◽  
Stress Functions

Abstract This paper presents a method of analyzing the stress distribution in a deep beam of finite length by superimposing two stress functions. The first stress function is chosen in the form of a trigonometric series which satisfies all but one of the boundary conditions—that of zero normal stress on the ends of the beam. The principle of least work is then used to obtain a second stress function giving the distribution of normal stress on the ends which is left by the first stress function. By superimposing the two solutions, all the boundary conditions are satisfied. Two particular cases of a given type of loading are solved in this way to investigate the stresses in a deep beam and their deviation from the ordinary beam theory. In addition, an approximate solution by the numerical method of finite difference is worked out for one of the two cases. Results from the two methods are compared and discussed. A method of obtaining an exact solution to the problem is given in an Appendix.

The Stresses in a Thick Cylinder Having a Square Hole Under Concentrated Loading

1958 ◽  
Vol 25 (4) ◽  
pp. 571-574
Author(s):  
Masaichiro Seika
Keyword(s):  
Stress Distribution ◽  
Complex Variable ◽  
Complex Variable Method ◽  
Variable Method ◽  
Numerical Examples ◽  
Concentrated Loading ◽  
Thick Cylinder ◽  
Square Hole

Abstract This paper contains a solution for the stress distribution in a thick cylinder having a square hole with rounded corners under the condition of concentrated loading. The problem is investigated by the complex-variable method, associated with the name of N. I. Muskhelishvili. The unknown coefficients included in the solution are determined by the method of perturbation. Numerical examples of the solution are worked out and compared with the results available.

Hertzian Contact and Adhesion of Elastomers

1969 ◽  
Vol 91 (4) ◽  
pp. 732-737 ◽  
Author(s):  
Richard C. Drutowski
Keyword(s):  
Stress Distribution ◽  
Tensile Stress ◽  
Contact Area ◽  
Hard Sphere ◽  
Continuous Measurement ◽  
Hertzian Contact ◽  
Initial Contact ◽  
Circular Zone ◽  
Outer Annulus ◽  
Contact Size

The contact of a hard sphere with a flat elastomer is examined both analytically and experimentally when adhesive stresses are present. Use of a transparent spherical indenter enables continuous measurement of contact size while the samples are pulled apart. For any combination of load and contact area, the superposition of a Hertz and a Boussinesq stress distribution separates the contact into a circular zone under compression and an outer annulus under tension. During separation, while the contact size decreases and the tensile annulus becomes a larger percentage of the total contact, the average tensile stress remains constant. This average adhesive is a material property which is easily measured and is shown to be invariant with respect to indenter radius and initial contact pressure. An application of this analysis to opaque indenters is described.

Contact Model of Sealing Surfaces for Flange and Metallic Gasket Based on Fractal Theory

2011 ◽  
Vol 308-310 ◽  
pp. 1571-1576 ◽  
Author(s):  
Xiu Feng ◽  
Feng Lu ◽  
Guo Liang Shen
Keyword(s):  
Compressive Stress ◽  
Contact Area ◽  
Fractal Theory ◽  
Pressure Vessels ◽  
Contact Model ◽  
Major Influence ◽  
Compressive Stresses ◽  
Bolted Flange ◽  
The Relationship ◽  
Scale Coefficient

Metallic gasket seals are widely used in pressure vessels and piping. The failure of sealing systems is mostly caused not by the strength of flanges or bolts but by the leakage of the connections. The contact area of sealing surface has a major influence on the leakage of the bolted flange connections. The contact model of sealing surfaces of the flange and the metallic gasket was established on the basis of the modified M-B model, and the relationship between the contact area and the compressive stress is obtained. It’s found that the bigger the compressive stress, the bigger the contact area. When the compressive stresses are identical, the bigger fractal dimension and the less scale coefficient, the bigger the contact area. These can be used in the evaluation of sealing behavior of metallic gaskets.

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