scholarly journals Effect of Initial Backfill Temperature on the Deformation Behavior of Early Age Cemented Paste Backfill That Contains Sodium Silicate

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Aixiang Wu ◽  
Yong Wang ◽  
Bo Zhou ◽  
Jiahua Shen

Enhancing the knowledge on the deformation behavior of cemented paste backfill (CPB) in terms of stress-strain relations and modulus of elasticity is significant for economic and safety reasons. In this paper, the effect of the initial backfill temperature on the CPB’s stress-strain behavior and modulus of elasticity is investigated. Results show that the stress-strain relationship and the modulus of elasticity behavior of CPB are significantly affected by the curing time and initial temperature of CPB. Additionally, the relationship between the modulus of elasticity and unconfined compressive strength (UCS) and the degree of hydration was evaluated and discussed. The increase of UCS and hydration degree leads to an increase in the modulus of elasticity, which is not significantly affected by the initial temperature.

1970 ◽  
Vol 7 (1) ◽  
pp. 99-110
Author(s):  
Prajwal Lal Pradhan ◽  
C.V. R. Murty ◽  
Karl Vincent Hoiseth ◽  
Mohan Prasad Aryal

This paper puts forward an idealization of stress-strain curve of structural materials like bricks, and mortar. In this model, below yield limit, the pattern of the stress-strain relationship is assumed to be linear i.e. modulus of elasticity remains unchanged, whereas beyond the limit, the relationship is supposed to be curvilinear. A quadratic stress function is assumed to formulate the stress-strain curve passing through the points of yield stress sy and ultimate stress su. Experimental investigation on the cube-tests of specimen for brick samples and mortar cubes are also presented for the verification of idealized stress-strain relationships.Journal of the Institute of Engineering, Vol. 7, No. 1, July, 2009 pp. 99-110doi: 10.3126/jie.v7i1.2067


2001 ◽  
Vol 695 ◽  
Author(s):  
Vincent D. Jardret ◽  
Pierre Morel ◽  
Nicolas Conté

ABSTRACTContact mechanics for indentation testing with spherical indenter is very attractive. Numerous projects have established equations to define strain and stress distribution in order to obtain stress-strain relationship from a single indentation experiment. Also a large number of studies have focused on metallic materials with the objective of estimating the yield point.The subject of this work is to analyze the behavior of various polymeric materials during spherical indentation testing at various temperature in order to observe the relationship between the indentation behavior and compression stress-strain behavior of the same materials as a function of temperature. Thermal effects on the indentation data are used to understand the actual effects of the mechanical properties on the indentation behavior. In addition to the load, displacement, and frequency specific stiffness information, topographic analysis of the residual indentation print is used to accurately estimate the contact area, therefore, validate the indentation models for contact depth calculations using spherical indentation. Results presented in this article include spherical indentation data obtained on PMMA and Polycarbonate over a range of temperature from 5°C to l00°C.


1991 ◽  
Vol 64 (2) ◽  
pp. 234-242
Author(s):  
R. F. Bauer ◽  
A. H. Crossland

Abstract Properties of the individual phases in a 70/30 carbon-black-loaded BR/NR blend could be successfully resolved using large deformation stress-strain modelling. Since the dispersed NR phase of the example had a lower modulus than the continuous BR phase, the interaction between the blend phases could be modelled by a simple parallel coupling arrangement. The stress behavior of each individual carbon-black-loaded polymer phase was then determined with respect to strain using a specially derived stress-strain relationship. The blend components also have to be characterized with respect to state-of-cure by empirically establishing how the parameters in the stress-strain relationship vary with respect to cure. The properties of the phases in the blend are then determined by finding the combination of component parameters which precisely reproduce the stress-strain behavior of the blend. In the demonstration example of this paper, there was evidence of a significant amount of curative migration between phases during the vulcanization process.


1957 ◽  
Vol 30 (4) ◽  
pp. 1027-1044 ◽  
Author(s):  
F. Horst Müller

Abstract This treatment of the stress-strain behavior of natural rubber is based upon experimental and theoretical data on the cold stretching of high polymers gathered from work being in progress for some time at Marburg. These investigations indicate that deformation processes of matter should not be treated exclusively as purely mechanical phenomena though this is still being done. Especially in the case of natural rubber there exist very thorough analyses of these heat effects caused by deformation. Their theoretical evaluation furnished the basis for the thermodynamic-statistical theory of rubber elasticity. This created the picture of a molecular mechanism which with new additions permitted the description of a host of details including those for stress-strain behavior. However the relationship between the shape of the stress-strain diagrams and any particular deformation condition can only be explained if the actions of the deformational heat effects upon the course of the deformation are considered. In the following an attempt will be made to discuss the actions of the heat effects, in other words to examine the deformation processes as mechanical-thermal ones. Although there are, at present, no experimental results on hand, the expected consequences for the deformational behavior of rubber will be surveyed. Experimental work is in progress.


2019 ◽  
Vol 141 (4) ◽  
Author(s):  
N. K. Sharma ◽  
M. D. Sarker ◽  
Saman Naghieh ◽  
Daniel X. B. Chen

Bone is a complex material that exhibits an amount of plasticity before bone fracture takes place, where the nonlinear relationship between stress and strain is of importance to understand the mechanism behind the fracture. This brief presents our study on the examination of the stress–strain relationship of bovine femoral cortical bone and the relationship representation by employing the Ramberg–Osgood (R–O) equation. Samples were taken and prepared from different locations (upper, middle, and lower) of bone diaphysis and were then subjected to the uniaxial tensile tests under longitudinal and transverse loading conditions, respectively. The stress–strain curves obtained from tests were analyzed via linear regression analysis based on the R–O equation. Our results illustrated that the R–O equation is appropriate to describe the nonlinear stress–strain behavior of cortical bone, while the values of equation parameters vary with the sample locations (upper, middle, and lower) and loading conditions (longitudinal and transverse).


1999 ◽  
Vol 15 (4) ◽  
pp. 177-184
Author(s):  
Ming-Lou Liu

AbstractThe stress-strain relationship of the sand and asphalt concrete materials is one of the most important research subjects in the past, and many conctitutive laws for these materials have been proposed in the last two decades. In this study, the Vermeer plasticity model is modified and used to predict the behavior of the sand and asphalt concrete materials under different stress path conditions. The results show that the predictions and test results agree well under different stress path conditions. However, the orignal Vermeer model can not predict the stress-strain behavior of the asphalt concrete. Finally, the modified Vermeer plasticity model is incorporated with the pavement rutting model to predict the rut depth of pavement structure under traffic loadings.


1969 ◽  
Vol 39 (2) ◽  
pp. 121-140 ◽  
Author(s):  
J. D. Collins ◽  
M. Chaikin

The general wool-type three-region behavior (i.e., Hookean, yield, and post-yield regions) is examined both theoretically and experimentally. In order to account for the influence of structural variation, the concept of effective area is introduced and it is shown that this effective area may differ according to the region in which the fiber is being extended. The general effects of effective-area variation on the regions of the stress-strain curve are derived and these are applied to a number of theoretical situations to demonstrate the stress-strain possibilities. It is shown that the relationship between the stress-strain curves for different sets of conditions can be quite complex since the nonuniformity relationships for the various regions of the curves and between curves may vary according to the conditions of testing. Two examples are given of the application of the theory in practice. The behavior of fibers in water and hydrochloric acid are compared and it is shown that there are variations in the effect of the acid within the fiber. The behavior of abraded fibers is examined and it is found that differences previously attributed by other workers to differences between the ortho and para components of the fibers are actually due to variable bond breakdown within the fiber material.


1990 ◽  
Vol 63 (5) ◽  
pp. 779-791 ◽  
Author(s):  
R. F. Bauer ◽  
A. H. Crossland

Abstract The unique stress-strain behavior of a carbon-black-loaded elastomer is due to the presence of a rigid, particulate phase, but also to the interaction of the elastomer chains with the filler. It is postulated that this interaction takes the form of adsorption on the filler-particle surface, which results in trapped entanglements. Upon deformation, the trapped chains are aligned parallel to the axis of stress. Thus, a practical stress-strain relationship could be developed which is capable to model the stress-strain behavior of compounds over the full range of extensions up to break. The analysis of a highly prestrained carbon-black-loaded NR compound in which the entanglement effect had been mechanically destroyed, demonstrated that the “sea-island” (SIP) coupling arrangement is most suitable for accounting for the interaction effect of the elastomer and carbon black. For moderately prestrained carbon-black-loaded NR and BR compounds a good fit of theory to experiment is obtained for a combination of the SIP coupling arrangement and the specially derived stress-strain relationship. Thus, a practical method is available for describing the deformation of carbon-black-loaded elastomers and for the modelling of carbon-black-loaded elastomer blends.


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