Drilling-Hole-Loading Method for Measuring Tensile Strength of Irregular Small Stones

2012 ◽  
Vol 239-240 ◽  
pp. 649-653
Author(s):  
Jin Chen ◽  
Ming Liu ◽  
Jie Min Liu
Keyword(s):  
Tensile Strength ◽  
Circular Hole ◽  
Standard Specimen ◽  
Hole Drilling ◽  
Theoretical Formula ◽  
Test Device ◽  
Drilling Hole ◽  
Loading Method ◽  
Set Up ◽  
Theoretical Stress

Drilling-Hole-Loading method is applied to predicting and measuring the tensile strength of irregular small-size stones. According to this method, a circular-hole must be drilled at the center of the irregular small-size stone. The mechanical model of the stone with a circular-hole and subjected to a pair of equivalent collinear pull forces is set up. The normal stress strain distributions on the critical section are anlyzed. Theoretical stress concentrated factor equation related to the hole diameter is calculated. Based on the static equilibrium theory, the theoretical formula of predicting the tensile strength of irregular small-size stones is established. Based on the theoretical formula, the test device for measurement of the tensile strength of the stone was designed. The tensile strength of a kind of bluestone was measured. The results show that the tensile strength predicted by Drilling-Hole-Loading method is a little lower than that of the standard specimen of stone without hole. Drilling-Hole-Loading method can be used to predict the tensile strength of brittle material and irregular small-size stones.

Research on Mill Longitudinal Stiffness Calculation of Wide Hot Strip Mills

2011 ◽  
Vol 211-212 ◽  
pp. 240-245
Author(s):  
Lian Sheng Wang ◽  
Quan Yang ◽  
An Rui He ◽  
Tian Wu Liu ◽  
De Fu Guo ◽  
...  
Keyword(s):  
Hydraulic System ◽  
Functional Relationship ◽  
Theoretical Formula ◽  
Strip Line ◽  
Geometric Accuracy ◽  
Parallel Connection ◽  
Hot Strip ◽  
Longitudinal Stiffness ◽  
Hot Strip Mills ◽  
Set Up

Mill is always weighed by its longitudinal stiffness. The prediction precision of longitudinal stiffness related strip geometric accuracy. Taking 1700mm hot strip line as research object, stiffness of housing, bearing wall and roll was calculated by finite elements method(FEM), hydraulic system stiffness was obtained by theoretical formula. Analyzing vertical system and structural symmetry of mill, functional relationship between longitudinal stiffness and its components stiffness was derived according to series or parallel connection with various components. Longitudinal stiffness was the basis on thickness set-up model. Calculation result was verified by practical test.

scholarly journals Relations between indirect tensile and flexural strengths for dry and plastic concretes

2013 ◽  
Vol 6 (6) ◽  
pp. 854-874 ◽  
Author(s):  
J. T. Balbo
Keyword(s):  
Tensile Strength ◽  
Concrete Slab ◽  
Plane Stress State ◽  
Concrete Mixtures ◽  
Technological Control ◽  
Strength Tests ◽  
Indirect Tensile ◽  
Actual Strength ◽  
Basic Concepts ◽  
Set Up

Indirect tensile strength is not usually used for concrete mixtures proportioning and its technological control; flexural strength tests under third point loads arrangement are the pattern for such goals. Indeed, neither of such tests have the capability to set up the actual strength of a concrete slab since its response is under plane stress state. A critical review of the basic concepts on both kinds of tests allows foreseeing its limitations as well as how to overcome such shortcomings. At last correlations between the two kinds of tensile strength are presented considering dry and plastic concretes typically applied on paving, corroborating to former results achieved for plastic concretes.

scholarly journals A Study on the Entanglement and High-Strength Mechanism of Spunlaced Nonwoven Fabric of Hydrophilic PET Fibers

2013 ◽  
Vol 8 (4) ◽  
pp. 155892501300800 ◽  
Author(s):  
Hong Wang ◽  
Jingjing Zhu ◽  
Xiangyu Jin ◽  
Haibo Wu
Keyword(s):  
Tensile Strength ◽  
High Strength ◽  
Nonwoven Fabric ◽  
Fiber Content ◽  
Nonwoven Fabrics ◽  
Pull Out ◽  
Fundamental Research ◽  
Pet Fibers ◽  
Set Up

Spunlaced nonwoven fabrics have been widely used recently, but fundamental research on the spunlaced nonwoven process is relatively weak. It is inexplicit until now how fibers are entangled with each other during the hydroentangling process. In this paper, a pull-out experiment designed to study the entanglement properties of spunlaced nonwoven fabrics using common and hydrophilic PET fibers as objects is described. It was found that the broken fiber content can be used to represent the entanglement intensity of the spunlaced nonwoven fabrics. In addition, a formula was set up to calculate the tensile strength of the spunlaced nonwoven fabric based on its pull-out behavior.

Versatile Work Holding Device for Hole Drilling in Small-Scale Production Workshops

2007 ◽  
Vol 18-19 ◽  
pp. 481-486
Author(s):  
John U. Okoli ◽  
Tamuno K. Jinyemiema
Keyword(s):  
Steel Plates ◽  
Hole Drilling ◽  
Small Scale ◽  
Work Piece ◽  
Scale Production ◽  
Production Operation ◽  
Irregular Shapes ◽  
Holding Device ◽  
Drilling Operations ◽  
Set Up

This devise addresses the inadequacies of providing a quick means of holding jobs of irregular shapes such as are encountered in small scale fabrication workshops. The conventional bench vise often does not provide the adequate grip for such shapes so that attachments in the form of V blocks are usually provided to enhance the grip before drilling operations are carried out. This versatile work holding device enables fabricators to perform drilling and other production operations on a work piece. This device produced from mild steel plates uses the toggle principle to provide rapid grip. Comparative tests on time span in the use of this device and the bench vice for job set up, production operation and then disassembly showed that time is gained with use of the device.

scholarly journals Investigation of Interlaminar Defects and their Influence on Interlaminar Strength

1996 ◽  
Vol 5 (4) ◽  
pp. 096369359600500
Author(s):  
J Ziao ◽  
J Tao
Keyword(s):  
Tensile Strength ◽  
Large Scale ◽  
Peel Strength ◽  
Test Method ◽  
Bending Test ◽  
Four Point Bending ◽  
Transverse Tensile ◽  
Interlaminar Shear ◽  
Transverse Tensile Strength ◽  
Set Up

In this paper, we directed our attention to the interlaminar defects and their influence on the interlaminar strengths. With the aid of a S-570 scanning electron microscope, the morphology and distribution of interlaminar defects were inspected and documented. According to their shape, size and cause of formation, the defects were classified into five types: flakiness void, irregular shaped debond, local imperfectly cured resin, debond in two multi-directional plies, and inhomogeneous fibers and the large scale debond by these fibers. The cause of defects formation was discussed by analyzing the manufacturing process of composites. The influence of defects on the interlaminar strength and its mechanism was analyzed experimentally and theoretically. The results indicate that these defects, with different effects, decrease the interlaminar strength because they form interlaminar cracks, and the interlaminar shear strength is less affected than interlaminar tensile strength, which is measured according to GB4944 test method. To comprehend defects distribution effect, a four-point-bending test method was introduced to measure the interlaminar peel strength, and a discussion was made on the correlation between the interlaminar tensile strength, interlaminar peel strength and in-plane transverse tensile strength. Finally the concept of interlaminar defect coefficient, which can be used to characterize the defects, was set up and the formula to calculate it was proposed.

Measurement of Residual Stress in Water Pipe Welds Using the Hole-Drilling Technique

2007 ◽  
Vol 353-358 ◽  
pp. 2419-2422
Author(s):  
Jung Hun Choi ◽  
Jong Hyun Baek ◽  
Dae Jin Kim ◽  
Jae Mean Koo ◽  
Chang Sung Seok
Keyword(s):  
Residual Stress ◽  
Size Effect ◽  
Standard Specimen ◽  
Weld Zone ◽  
Hole Drilling ◽  
Test Results ◽  
Water Pipe ◽  
Fatigue Load ◽  
Drilling Technique ◽  
Fatigue Characteristics

In case of large steel water pipe, it have been observed that its fracture mostly occurs due to the complicated outside fatigue load on the pipe in the underground. It is also well known that its damage and leakage happen mainly in a weld zone. In this study we evaluated the fatigue characteristics based on size effect and residual stress by comparing the test results on the standard specimen collected from real pipe with those on full scale pipe.

A Measurement Method of Tensile Strength for Irregular Small Stones

2014 ◽  
Vol 507 ◽  
pp. 281-285 ◽  
Author(s):  
Jin He Gao ◽  
Shou Long Zhang ◽  
Yan Bin Huang
Keyword(s):  
Tensile Strength ◽  
Failure Load ◽  
Round Hole ◽  
Mechanics Model ◽  
Measuring Devices ◽  
Loading Method ◽  
Distribution Rule ◽  
Small Stone ◽  
Porous Strip ◽  
The Impact

This article studied the drilling loading method for the tensile strength of irregular small-stone, designed the measuring devices, and addressed the measurement problems of irregular small-stone tensile strength. Based on static equilibrium theory, it analyzed the distribution rule of tensile stress in dangerous section, and established the mechanics model of drilling loading method. In considering the impact rules of characteristic destruction size and round-hole size on the hole-edge stress concentration, on this basis it established the theoretical formulas of measuring the tensile strength of brittle materials. It practically measured the failure load of small drilling bluestone, introduced the failure load into the theoretical measurement formula of brittle material tensile strength, and then obtained the tensile strength of stones, while it measured the tensile strength of non-porous strip specimen. The tensile strength of irregular stones measured by the drilling loading method is basically consistent with the tensile strength obtained from the tensile test of non-porous strip specimen, and therefore the drilling loading method is able to reasonably measure the tensile strength of small stones.

Experimental Research on Calculation Parameters of GFRP Bars Tensile Strength

2014 ◽  
Vol 1049-1050 ◽  
pp. 272-275
Author(s):  
Qing Ping Jin ◽  
Zu Jia Zheng ◽  
Liang Li Xiao
Keyword(s):  
Tensile Strength ◽  
Composite Material ◽  
Tensile Test ◽  
Experimental Research ◽  
Intensity Distribution ◽  
Distribution Model ◽  
Theoretical Formula ◽  
Failure Strength ◽  
Gfrp Bars ◽  
Fiber Materials

A tensile test on the 18mm diameter (φ18) and 25mm (φ25) GFRP bars was conducted to observe the tensile apparent characteristics and failure strength. The value calculated by failure strength fomula and the experimental value were ,contrasted to study the parameters and value of the strength calculating formula,, and drawn the conclusions as follows: The φ18 and φ25 GFRP bars' failure strength is effected by fiber materials, enhance materials itself and interface performance. The φ18 bars’ failure strength is about 10% higher than φ25 bars’. The deviation between the calculated value and the actual value is more than 30%. k is the correction parameter in theoretical formula, kφ18=0.76, kφ25 = 0.68 is appropriate. Based on statistical intensity distribution model of GFRP bars’ failure strength, reference stresses value of the φ18 and φ25 GFRP bars are different and the diameters of GFRP bars increases to weaken the strength of the composite material. The reducing rate of the reference stresses is significantly affected by the diameters. The diameters effect is greater than the fiber content effect.

scholarly journals Using the Mathematical Criterion of Gas Pipeline Failure to Determine the Remaining Operation Life

2021 ◽  
Vol 248 ◽  
pp. 04021
Author(s):  
Minsariya Bayburova ◽  
Zulfiya Ismagilova
Keyword(s):  
Tensile Strength ◽  
Cyclic Loading ◽  
Main Pipeline ◽  
Strength Criteria ◽  
Loading Method ◽  
Underground Pipelines ◽  
Strength Tests ◽  
Pipeline Failure ◽  
Pipeline Route ◽  
Wear Damage

During the years of operation, underground pipelines deteriorate because of aging, wear, damage, and destruction. A comprehensive inspection of the main pipeline revealed various defects on a certain pipeline route section. To identify the remaining operation life of the pipeline, a number of hydraulic tensile strength tests were performed using the cyclic loading method. The authors propose to calculate the minimum allowable wall thickness capable of withstanding the maximum internal pressure, as an alternative to cyclic hydraulic tests. The strength calculations were performed using the well-known mathematical strength criteria proposed by K.V. Zakharov and I.I. Goldenblatt and V.A. Kopnov.

scholarly journals Compositionally Graded Hydrophobic UV-Cured Coatings for the Prevention of Glass Stress Corrosion

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 424 ◽  
Author(s):  
Sara Dalle Vacche ◽  
Gregorio Mariggiò ◽  
Alessandra Vitale ◽  
Roberta Bongiovanni ◽  
Mauro Corrado
Keyword(s):  
Tensile Strength ◽  
Stress Corrosion ◽  
Mechanical Load ◽  
Load Test ◽  
Good Adhesion ◽  
Compositional Profile ◽  
Double Ring ◽  
Structural Applications ◽  
Graded Coating ◽  
Set Up

The use of glass in architecture is growing and is moving towards structural applications. However, the tensile strength of glass cannot be fully exploited because of stress corrosion. This is a corrosion triggered by stress applied to the material and dependent on environmental factors such as humidity and temperature. To protect glass from stress corrosion, we developed a UV-cured coating, characterized by hydrophobicity, barrier to water vapor properties, and good adhesion to glass, thanks to a compositional profile. The coating was obtained by combining a cycloaliphatic diacrylate resin with a very low amount of a perfluoropolyether methacrylate co-monomer, which migrated to the free surface, creating a compositionally graded coating. The adhesion to glass was improved, using as a primer an acrylated silane able to co-react with the resins. With a mechanical load test using the coaxial double ring set-up, we proved that the coating is effective in the inhibition of stress corrosion of glass plates, with an increase of 76% of tensile strength.

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