A Mechanical Test Procedure for Avalanche Snow

AbstractThe design, construction, and testing of a portable constant strain-rate testing machine for determining the mechanical behavior of avalanche snow is described. The machine is intended for use in determining the stress strain time behavior of low-density natural snows in the field. A technique for making direct measurements of strain in the snow sample is described and stress-strain curves are presented for strain-rates ranging from 0.5 to 5.0 x 10-5s-1. The densities of the snow samples tested range from 186 to 335 kg m-3Ultimate-strength data and relaxation curves arc also presented.

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A Mechanical Test Procedure for Avalanche Snow

Journal of Glaciology ◽

10.3189/s0022143000215694 ◽

1977 ◽

Vol 19 (81) ◽

pp. 489-497 ◽

Cited By ~ 1

Author(s):

S. L. McCabe ◽

F. W. Smith

Keyword(s):

Mechanical Test ◽

Test Procedure ◽

Testing Machine ◽

Constant Strain Rate ◽

Time Behavior ◽

Stress Strain ◽

Direct Measurements ◽

Natural Snow ◽

Relaxation Curves ◽

Design Construction

AbstractThe design, construction and testing of a portable, constant strain-rate testing machine for determining the mechanical behavior of avalanche now is described. The machine is intended for use in determining the stress-strain-time behavior of low-density natural snow in the field. A technique for making direct measurements of strain in the snow sample is described and stress-strain curves are presented for strain-rates ranging from 0.5 to 5.0 × 10−5 s−1. The densities of the snow samples tested range from 186 to 335 kg m−3. Ultimate-strength data and relaxation curves are also presented.

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A Mechanical Test Procedure for Avalanche Snow

Journal of Glaciology ◽

10.3189/s0022143000215700 ◽

1977 ◽

Vol 19 (81) ◽

pp. 657-657

Author(s):

S. L. McCabe ◽

F. W. Smith

Keyword(s):

Mechanical Test ◽

Test Procedure ◽

Testing Machine ◽

Constant Strain Rate ◽

Time Behavior ◽

Stress Strain ◽

Direct Measurements ◽

Natural Snow ◽

Relaxation Curves ◽

Design Construction

AbstractThe design, construction and testing of a portable, constant strain-rate testing machine for determining the mechanical behavior of avalanche now is described. The machine is intended for use in determining the stress-strain-time behavior of low-density natural snow in the field. A technique for making direct measurements of strain in the snow sample is described and stress-strain curves are presented for strain-rates ranging from 0.5 to 5.0 × 10−5 s−1. The densities of the snow samples tested range from 186 to 335 kg m−3. Ultimate-strength data and relaxation curves are also presented.

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Stress–strain–time behavior of deep sea clays

Canadian Geotechnical Journal ◽

10.1139/t83-059 ◽

1983 ◽

Vol 20 (3) ◽

pp. 517-531 ◽

Cited By ~ 6

Author(s):

A. J. Silva ◽

K. Moran ◽

S. A. Akers

Keyword(s):

Deep Sea ◽

Triaxial Compression ◽

Constant Strain Rate ◽

Triaxial Tests ◽

Time Behavior ◽

Compression Tests ◽

Creep Tests ◽

Stress Strain ◽

The North ◽

Deep Sea Sediments

Summary results are presented of a comprehensive experimental study to investigate the strength, stress–strain properties, and creep behavior of fine-grained deep sea sediments. Isotropically (CIU) and anisotropically (CAU) consolidated undrained triaxial tests and drained triaxial creep tests were performed on undisturbed and reconstituted–reconsolidated (remolded) samples of smectite-rich and illite-rich deep sea clays from the North Central Pacific.The CIU Mohr–Coulomb parameters for remolded smectite [Formula: see text] were nearly identical to the undisturbed material [Formula: see text]. The parameters for remolded illite [Formula: see text] were also not significantly different than for the undisturbed material [Formula: see text].The undrained shear strength versus water content relationship (qf vs. wf) for remolded smectite is much lower than for the undisturbed material, whereas for illite the remolded strength is only slightly lower. Therefore it appears that smectite is much more sensitive than illite to the type of remolding used in these studies.The CAU tests showed that K0 agrees well with the Jaky equation, [Formula: see text]. The Mohr–Coulomb parameters were somewhat lower than the corresponding CIU results.Undisturbed and remolded samples were tested at stress levels of 10, 25, 40, and 65% of the Mohr–Coulomb strength for the determination of triaxial drained creep properties. Different relationships between stress level, strain, and time were determined for the two materials. A secondary state of creep, defined as a period of constant strain rate, was not consistently observed. Comparisons with terrestrial clays and near shore material display similar strengths of the deep sea sediments and greater deformation potential during long-term loading. Keywords: stress–strain behavior, creep, deep sea sediments, stress–strain–time behavior, triaxial compression tests.

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Measurement of the Constitutive Behavior of Underfill Encapsulants

2003 International Electronic Packaging Technical Conference and Exhibition, Volume 2 ◽

10.1115/ipack2003-35321 ◽

2003 ◽

Cited By ~ 1

Author(s):

M. Saiful Islam ◽

Jeffrey C. Suhling ◽

Pradeep Lall

Keyword(s):

Flip Chip ◽

Mechanical Response ◽

Capillary Flow ◽

Mechanical Test ◽

Testing Machine ◽

Production Equipment ◽

Uniaxial Tensile ◽

Stress Strain ◽

Strain Behavior ◽

Nonlinear Stress

Reliable, consistent, and comprehensive material property data are needed for microelectronic encapsulants for the purpose of mechanical design, reliability assessment, and process optimization of electronic packages. In our research efforts, the mechanical responses of several different capillary flow snap cure underfill encapsulants are being characterized. A microscale tension-torsion testing machine has been used to evaluate the uniaxial tensile stress-strain behavior of underfill materials as a function of temperature, strain rate, specimen dimensions, humidity, thermal cycling exposure, etc. A critical step to achieving accurate experimental results has been the development of a sample preparation procedure that produces mechanical test specimens that reflect the properties of true underfill encapsulant layers. In the developed method, 75–125 μm (3–5 mil) thick underfill uniaxial tension specimens are dispensed and cured using production equipment and the same processing conditions as those used with actual flip chip assemblies. Although several underfills have been examined, this work features results for the mechanical response of a single typical capillary flow snap cure underfill. A three parameter hyperbolic tangent empirical model has been shown to provide accurate fits to the observed underfill nonlinear stress-strain behavior over a range of temperatures and strain rates. In addition, typical creep data are presented.

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Use of a Durometer to Assess Onion Bulb Hardness

Experimental Agriculture ◽

10.1017/s0014479700008796 ◽

1978 ◽

Vol 14 (3) ◽

pp. 269-272 ◽

Cited By ~ 3

Author(s):

J. F. M. Fennell

Keyword(s):

Tensile Testing ◽

Test Procedure ◽

Testing Machine ◽

Onion Bulb ◽

Tensile Testing Machine ◽

Varietal Differences ◽

Onion Bulbs ◽

Non Destructive

SUMMARYThe use of a durometer to assess hardness of onion bulbs is described, and compared with the use of a tensile testing machine. Results from the two tests were closely correlated, and significant varietal differences were detected in bulb hardness by both machines. The durometer is of particular value because of the simplicity and non-destructive nature of the test procedure.

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An Experimental Study on the Effect of Prior Plastic Straining on Creep Behavior of 304 Stainless Steel

Journal of Engineering Materials and Technology ◽

10.1115/1.2904207 ◽

1993 ◽

Vol 115 (2) ◽

pp. 200-203 ◽

Cited By ~ 11

Author(s):

Z. Xia ◽

F. Ellyin

Keyword(s):

Stainless Steel ◽

Plastic Strain ◽

Strain Rate ◽

Creep Behavior ◽

Test Procedure ◽

Constant Strain Rate ◽

304 Stainless Steel ◽

Creep Model ◽

Plastic Strain Rate ◽

Creep Tests

Constant strain-rate plastic straining followed by creep tests were conducted to investigate the effect of prior plastic straining on the subsequent creep behavior of 304 stainless steel at room temperature. The effects of plastic strain and plastic strain-rate were delineated by a specially designed test procedure, and it is found that both factors have a strong influence on the subsequent creep deformation. A creep model combining the two factors is then developed. The predictions of the model are in good agreement with the test results.

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Stress Analysis of Pipeline Subjected to Differential Frost Heave

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2013-97726 ◽

2013 ◽

Author(s):

Yan Di ◽

Jian Shuai ◽

Lingzhen Kong ◽

Xiayi Zhou

Keyword(s):

Strain Analysis ◽

Element Model ◽

Frozen Soil ◽

Computational Method ◽

Frost Heave ◽

Safe Operation ◽

Stress Strain ◽

Segregation Potential ◽

Differential Frost Heave ◽

Design Construction

Frost heave must be considered in cases where pipelines are laid in permafrost in order to protect the pipelines from overstress and to maintain the safe operation. In this paper, a finite element model for stress/strain analysis in a pipeline subjected to differential frost heave was presented, in which the amount of frost heave is calculated using a segregation potential model and considering creep effects of the frozen soil. In addition, a computational method for the temperature field around a pipeline was proposed so that the frozen depth and temperature variation gradient could be obtained. Using the procedure proposed in this paper, stress/strain can be calculated according to the temperature on the surface of soil and in a pipeline. The result shows the characteristics of deformation and loading of a pipeline subjected to differential frost heave. In general, the methods and results in this paper can provide a reference for the design, construction and operation of pipelines in permafrost areas.

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Stress-strain curve of concretes with recycled concrete aggregates: analysis of the NBR 8522 methodology

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952017000300002 ◽

2017 ◽

Vol 10 (3) ◽

pp. 547-567 ◽

Cited By ~ 2

Author(s):

D. A. GUJEL ◽

C. S. KAZMIERCZAK ◽

J. R. MASUERO

Keyword(s):

Test Procedure ◽

Strain Curve ◽

Recycled Concrete ◽

Load Test ◽

Recycled Aggregates ◽

Elastic Behavior ◽

It Use ◽

Stress Strain Curve ◽

Stress Strain ◽

Brazilian Standard

ABSTRACT This work analyses the methodology "A" (item A.4) employed by the Brazilian Standard ABNT 8522 (ABNT, 2008) for determining the stress-strain behavior of cylindrical specimens of concrete, presenting considerations about possible enhancements aiming it use for concretes with recycled aggregates with automatic test equipment. The methodology specified by the Brazilian Standard presents methodological issues that brings distortions in obtaining the stress-strain curve, as the use of a very limited number of sampling points and by inducing micro cracks and fluency in the elastic behavior of the material due to the use of steady stress levels in the test. The use of a base stress of 0.5 MPa is too low for modern high load test machines designed do high strength concrete test. The work presents a discussion over these subjects, and a proposal of a modified test procedure to avoid such situations.

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Flexibility of K3 and ProTaper universal instruments

Brazilian Dental Journal ◽

10.1590/s0103-64402011000300007 ◽

2011 ◽

Vol 22 (3) ◽

pp. 218-222 ◽

Cited By ~ 6

Author(s):

Renata Grazziotin-Soares ◽

Flares Barato Filho ◽

José Roberto Vanni ◽

Susimara Almeida ◽

Elias Pandonor Motcy de Oliveira ◽

...

Keyword(s):

Mechanical Test ◽

Testing Machine ◽

Universal System ◽

Universal Testing Machine ◽

The Third ◽

Universal Testing ◽

Before And After ◽

Level Of Significance ◽

Flexible Instruments

This study used a mechanical test to evaluate the flexibility of instruments from the K3 (conicity 0.04) and the ProTaper Universal systems when they were new and after 5 uses in simulated canals. Five sets of instruments of each system were tested: K3 (15, 20, 25, 30, 35, 40 and 45) and ProTaper Universal (S1, S2, F1, F2, F3, F4 and F5). Each set of instruments was used to prepare a simulated canal and the same set of instruments was used 5 times (50 canals). The number of each subgroup represented the number of uses: 0 (control), 1, 3 and 5 uses. Before and after each use, the instruments were submitted to a mechanical flexibility test performed in a Versat 502 universal testing machine. Interactions between the instrument and the number of uses were analyzed by ANOVA and Tukey's test at a 5% level of significance. Instruments from both systems presented lower flexibility after the third use compared to the flexibility obtained after uses 0 and 1 (p<0.05), and maintained the same flexibility after the fifth use. The flexibility of instruments from the K3 system decreased with the increase of diameter, irrespective of the number of uses. Among the instruments from the ProTaper Universal system, the shaping files presented greater flexibility than the finishing files. F2 and F3 were the least flexible instruments, and F4 and F5 presented flexibility values similar to those of F1.

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