In-situ Determination of Undrained Stress-strain Behavior of Sensitive Clays with the Pressuremeter

1972 ◽  
Vol 9 (3) ◽  
pp. 313-319 ◽  
Author(s):  
B. Ladanyi
Keyword(s):  
Direct Determination ◽  
Strain Curve ◽  
Strength Properties ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behavior ◽  
Expansion Curve ◽  
Laboratory Test Results

A theory originally proposed by Gibson and Anderson (1961) has been extended to enable a direct determination of the whole undrained stress-strain curve of the clay from the pressure-expansion curve obtained in a conventional pressuremeter test.When applied to some pressuremeter tests carried out in Leda clay in the Ottawa area, the method enabled us to determine the undrained stress-strain behavior of the clay up to axial strains of about 20%. It is thought that, when properly performed, the test is able to furnish the data on the undrained stress-strain and strength properties of sensitive clays comparable to the laboratory test results obtained on block samples. Its particular feature is that it also furnishes a true picture of the post-peak strength decrease in terms of shear strain which is usually difficult to obtain by any other type of test.

scholarly journals Stress-Strain Behavior of Cementitious Materials with Different Sizes

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jikai Zhou ◽  
Pingping Qian ◽  
Xudong Chen
Keyword(s):  
Flexural Strength ◽  
Size Effect ◽  
Cement Mortar ◽  
Strain Curve ◽  
Cementitious Materials ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behavior ◽  
Modified Equation ◽  
Good Agreement

The size dependence of flexural properties of cement mortar and concrete beams is investigated. Bazant’s size effect law and modified size effect law by Kim and Eo give a very good fit to the flexural strength of both cement mortar and concrete. As observed in the test results, a strong size effect in flexural strength is found in cement mortar than in concrete. A modification has been suggested to Li’s equation for describing the stress-strain curve of cement mortar and concrete by incorporating two different correction factors, the factors contained in the modified equation being established empirically as a function of specimen size. A comparison of the predictions of this equation with test data generated in this study shows good agreement.

Evaluation of Microindentation Test Results Using FEM Simulations for the Determination of the Mechanical Properties of Various Ferrous or Non Ferrous Materials

2005 ◽  
Author(s):  
K.-D. Bouzakis ◽  
A. Lontos
Keyword(s):  
Mechanical Properties ◽  
Strain Curve ◽  
Constitutive Law ◽  
Test Results ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Analytical Methodology ◽  
Ball Diameter ◽  
Steel Balls

The determination of the mechanical properties using the nano or macroindentation test results was developed in order to predict the mechanical properties of materials such as thin or thick coatings [1]. In the present paper a new method using a continuous FEM supported simulation of the microindentation results through a special tester, is proposed in order to predict the stress–strain curve of various ferrous or non ferrous materials that are being used as constructive materials in several machines or devices. The elasticity modulus is determined using a large spherical indenter tip and the stress strain curve using smaller steel balls. In the case of three deferent ball diameter indenter tips, the adopted experimental-analytical methodology present similar results regarding the constitutive law of the examined steel or aluminum specimens.

scholarly journals Stress-Strain Relationship of Ca(OH)2-Activated Hwangtoh Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Keun-Hyeok Yang ◽  
Ju-Hyun Mun ◽  
Hey-Zoo Hwang
Keyword(s):  
Compressive Strength ◽  
Strain Curve ◽  
Peak Stress ◽  
Actual Behavior ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behavior ◽  
Strain Relationship ◽  
Relationship Of ◽  
Strain Model

This study examined the stress-strain behavior of 10 calcium hydroxide (Ca(OH)2)-activated Hwangtoh concrete mixes. The volumetric ratio of the coarse aggregate (Vagg) and the water-to-binder (W/B) ratio were selected as the main test variables. TwoW/Bratios (25% and 40%) were used and the value ofVaggvaried between 0% and 40.0%, and 0% and 46.5% forW/Bratios of 25% and 40%, respectively. The test results demonstrated that the slope of the ascending branch of the stress-strain curve of Ca(OH)2-activated Hwangtoh concrete was smaller, and it displayed a steeper drop in stress in the descending branch, compared with those of ordinary Portland cement (OPC) concrete with the same compressive strength. This trend was more pronounced with the increase in theW/Bratio and decrease inVagg. Based on the experimental observations, a simple and rational stress-strain model was established mathematically. Furthermore, the modulus of elasticity and strain at peak stress of the Ca(OH)2-activated Hwangtoh concrete were formulated as a function of its compressive strength andVagg. The proposed stress-strain model predicted the actual behavior accurately, whereas the previous models formulated using OPC concrete data were limited in their applicability to Ca(OH)2-activated Hwangtoh concrete.

Determination of creep properties of frozen soils by means of the borehole stress relaxation test

1993 ◽  
Vol 30 (1) ◽  
pp. 170-186 ◽  
Author(s):  
B. Ladanyi ◽  
M. Melouki
Keyword(s):  
Stress Relaxation ◽  
Strength Properties ◽  
Frozen Soil ◽  
Relaxation Test ◽  
Test Results ◽  
Stress Relaxation Test ◽  
Frozen Soils ◽  
Frozen Sand

The objective of this investigation was to evaluate the potential use of the borehole stress relaxation test to determine the creep and strength properties of frozen soils in situ. The paper presents the results of a series of laboratory pressuremeter relaxation tests performed in frozen sand and compares three possible interpretation methods for deducing from the test results the creep and strength parameters of frozen soils. Key words : borehole relaxation, pressuremeter, in situ testing, creep and strength properties, frozen soil.

Determination of plastic stress-strain behavior by digital-image-processing techniques

1987 ◽  
Vol 27 (4) ◽  
pp. 414-422 ◽  
Author(s):  
S. M. Metwalli ◽  
A. R. Ragab ◽  
A. H. Kamel ◽  
A. Abdul Saheb
Keyword(s):  
Image Processing ◽  
Digital Image Processing ◽  
Digital Image ◽  
Stress Strain ◽  
Image Processing Techniques ◽  
Strain Behavior ◽  
Processing Techniques ◽  
Plastic Stress

Understanding Dynamic Recrystallization Behavior through a Delay Differential Equation Approach

2007 ◽  
Vol 558-559 ◽  
pp. 441-448 ◽  
Author(s):  
Jong K. Lee
Keyword(s):  
Differential Equation ◽  
Strain Rate ◽  
Critical Strain ◽  
Strain Curve ◽  
Single Peak ◽  
Strain Rates ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Strain Behavior ◽  
Delay Differential

During hot working, deformation of metals such as copper or austenitic steels involves features of both diffusional flow and dislocation motion. As such, the true stress-true strain relationship depends on the strain rate. At low strain rates (or high temperatures), the stress-strain curve displays an oscillatory behavior with multiple peaks. As the strain rate increases (or as the temperature is reduced), the number of peaks on the stress-strain curve decreases, and at high strain rates, the stress rises to a single peak before settling at a steady-state value. It is understood that dynamic recovery is responsible for the stress-strain behavior with zero or a single peak, whereas dynamic recrystallization causes the oscillatory nature. In the past, most predictive models are based on either modified Johnson-Mehl-Avrami kinetic equations or probabilistic approaches. In this work, a delay differential equation is utilized for modeling such a stress-strain behavior. The approach takes into account for a delay time due to diffusion, which is expressed as the critical strain for nucleation for recrystallization. The solution shows that the oscillatory nature depends on the ratio of the critical strain for nucleation to the critical strain for completion for recrystallization. As the strain ratio increases, the stress-strain curve changes from a monotonic rise to a single peak, then to a multiple peak behavior. The model also predicts transient flow curves resulting from strain rate changes.

Determination of the critical opening of a concentrator of finite radius from a stress-strain curve

1986 ◽  
Vol 18 (5) ◽  
pp. 664-668
Author(s):  
M. V. Shakhmatov ◽  
V. V. Erofeev ◽  
V. A. Lupin ◽  
A. A. Ostsemin
Keyword(s):  
Strain Curve ◽  
Stress Strain Curve ◽  
Finite Radius ◽  
Stress Strain ◽  
Critical Opening

scholarly journals Preparation and stress-strain behavior of in-situ epoxidized natural rubber/SiO2 hybrid through a sol-gel method

2018 ◽  
Vol 12 (2) ◽  
pp. 180-185 ◽  
Author(s):  
S. M. Li ◽  
T. W. Xu ◽  
Z. X. Jia ◽  
B. C. Zhong ◽  
Y. F. Luo ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Sol Gel ◽  
Epoxidized Natural Rubber ◽  
Stress Strain ◽  
Gel Method ◽  
Sol Gel Method ◽  
Strain Behavior
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