Improvement in the mechanical properties of steel N18K9M5T under the influence of applied stress during aging

1978 ◽  
Vol 20 (12) ◽  
pp. 984-988
Author(s):  
L. E. Alekseeva ◽  
M. D. Perkas ◽  
V. I. Sarrak
Keyword(s):  
Mechanical Properties ◽  
Applied Stress ◽  
Steel N18k9m5t

Friction and Bearing Loads on Buried Pipes

1973 ◽  
Vol 13 (03) ◽  
pp. 163-174
Author(s):  
Alexander Blake ◽  
Maurice Zaslawsky
Keyword(s):  
Mechanical Properties ◽  
Internal Friction ◽  
Applied Stress ◽  
Phase Difference ◽  
Poisson’S Ratio ◽  
Soil Mechanics ◽  
Poisson's Ratio ◽  
Stress Strain ◽  
Physical Constants ◽  
Design Analyses

Abstract Presented here are results of experimental and theoretical investigations of the behavior of downhole pipe, surrounded by Overton sand or gravel, when subjected to shock from nuclear explosion. The principal effects investigated arelongitudinal friction between the pipe and the stemming material andresistance offered by the stemming material to transverse motion of the pipe. Introduction Stemming materials such as Overton sand and pea gravel are widely used in underground nuclear pea gravel are widely used in underground nuclear testing to ensure containment of the explosion. Present-day theories of mechanics suitable for predicting stresses and displacements within an predicting stresses and displacements within an array of particles of such materials are rather limited because of the stress-strain-time behavior and complicated boundary conditions involved. Thus, measurements representing gross effects only and linearized models of analysis must be relied upon in making the majority of engineering decisions where soil-structure interactions are encountered. Furthermore, because of the number of variables and hardware constraints present in designing deep-hole emplacement systems, the emphasis should be on obtaining experimental data on fullscale or nearly full-scale structural components in association with stemming materials of actual field quality. The experiment discussed in this paper was directed toward the development of basic mechanical properties such as modulus of elasticity, friction characteristics during axial (longitudinal) pipe motion through stemming materials, resistance pipe motion through stemming materials, resistance of stemming materials to transverse pipe displacement, and related physical phenomena that may have further bearing on the usual mechanical properties employed in various design analyses. properties employed in various design analyses. During evaluation of the basic mechanical properties, an attempt was made to develop a properties, an attempt was made to develop a Poisson's ratio type of data for the stemming Poisson's ratio type of data for the stemming materials at hand by using both specialized equipment and standard test equipment normally employed in soil mechanics. The results of the study, however, should be interpreted with due regard to the particulate nature of stemming materials, which do not represent a continuum with well defined stress-strain relationships. To obtain meaningful data on friction and transverse resistance characteristics, a special test rig was designed with particular emphasis on minimizing the scale effects and experimental errors usually encountered. In mechanics the term "friction" is the resistance to motion of two moving objects or surfaces that touch. In this paper we speak of several different types of micron, and therefore some clarification is needed. The friction between sand or gravel and the down-hole pipe as we attempt to move the pipe is one type of friction. A similar type is the friction developed between sand or gravel and the steel block it rubs against in the direct shear test apparatus. Those two examples of friction are rather straightforward, however, the following two present some confusion because they are both referred to as internal friction:Internal friction as used by engineering scientists, physicists, and metallurgists may be defined as the conversion of the mechanical energy of a vibrating solid into heat. This is also referred to as the damping capacity and corresponds to a phase difference between the applied stress and phase difference between the applied stress and its resultant strain.b soil mechanics the concept of internal friction corresponds to friction between the surfaces of individual grains of sand or gravel. In granular materials, both kinds of internal friction occur. In this paper the term "internal friction" is referred to extensively and is used exclusively in the sense of friction between particles. particles. FUNDAMENTALS OF SOIL MECHANICS The mechanical behavior of earth materials such as sand or gravel can be described by suitable physical constants reflecting certain physical constants reflecting certain stress-deformation relations that may then be applied in customary engineering predictions. In dealing with the rigidity of rocks, Young's modulus, E, and Poisson's ratio, are commonly used, and soil Poisson's ratio, are commonly used, and soil mechanics utilizes basic concepts of the theory of elasticity. By analogy to this well established practice, related concepts utilizing elastic practice, related concepts utilizing elastic constants in loading and unloading can be made applicable to stemming materials. SPEJ P. 163

Contribution of intermediate filaments to cell stiffness, stiffening, and growth

2000 ◽  
Vol 279 (1) ◽  
pp. C188-C194 ◽  
Author(s):  
Ning Wang ◽  
Dimitrije Stamenović
Keyword(s):  
Mechanical Properties ◽  
Applied Stress ◽  
Extended Period ◽  
Direct Consequence ◽  
Cell Stiffness ◽  
Cell Integrity ◽  
Wild Type ◽  
The Difference ◽  
High Degree

It has been shown previously that intermediate filament (IF) gels in vitro exhibit stiffening at high-applied stress, and it was suggested that this stiffening property of IFs might be important for maintaining cell integrity at large deformations (Janmey PA, Evtenever V, Traub P, and Schliwa M, J Cell Biol 113: 155–160, 1991). In this study, the contribution of IFs to cell mechanical behavior was investigated by measuring cell stiffness in response to applied stress in adherent wild-type and vimentin-deficient fibroblasts using magnetic twisting cytometry. It was found that vimentin-deficient cells were less stiff and exhibited less stiffening than wild-type cells, except at the lowest applied stress (10 dyn/cm2) where the difference in the stiffness was not significant. Similar results were obtained from measurements on wild-type fibroblasts and endothelial cells after vimentin IFs were disrupted by acrylamide. If, however, cells were plated over an extended period of time (16 h), they exhibited a significantly greater stiffness before than after acrylamide, even at the lowest applied stress. A possible reason could be that the initially slack IFs became fully extended due to a high degree of cell spreading and thus contributed to the transmission of mechanical stress across the cell. Taken together, these findings were consistent with the notion that IFs play important roles in the mechanical properties of the cell during large deformation. The experimental data also showed that depleting or disrupting IFs reduced, but did not entirely abolish, cell stiffening. This residual stiffening might be attributed to the effect of geometrical realignment of cytoskeletal filaments in the direction of applied load. It was also found that vimentin-deficient cells exhibited a slower rate of proliferation and DNA synthesis than wild-type cells. This could be a direct consequence of the absence of the intracellular IFs that may be necessary for efficient mediation of mechanical signals within the cell. Taken together, results of this study suggest that IFs play important roles in the mechanical properties of cells and in cell growth.

Mechanical properties of plates of maraging steel N18K9M5T

1970 ◽  
Vol 12 (2) ◽  
pp. 147-149 ◽  
Author(s):  
G. A. Beresnev ◽  
L. D. Pilikina ◽  
Yu. I. Kataev
Keyword(s):  
Mechanical Properties ◽  
Maraging Steel ◽  
Steel N18k9m5t ◽  
Maraging Steel N18k9m5t

Effects of Static Stress on the Mechanical Properties of Cultured Collagen Fascicles From the Rabbit Patellar Tendon

2001 ◽  
Vol 124 (1) ◽  
pp. 85-93 ◽  
Author(s):  
Ei Yamamoto ◽  
Wataru Iwanaga ◽  
Hiroshi Miyazaki ◽  
Kozaburo Hayashi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Applied Stress ◽  
Patellar Tendon ◽  
Control Level ◽  
Peak Stress ◽  
Static Stress ◽  
Tangent Modulus

In-vitro tissue culture experiments were performed to study the effects of static stress on the mechanical properties of collagen fascicles obtained from the rabbit patellar tendon. After collagen fascicles having the diameter of approximately 300 μm were cultured for 1 and 2 wk under static stress between 0 and 3 MPa, their mechanical properties and crimp morphology were determined using a micro-tensile tester and a light microscope, respectively. The tensile strength and tangent modulus of the fascicles were significantly decreased by culture under no load compared to control fascicles. A statistically significant correlation, which was described by a quadratic curve, was observed between applied stress and tensile strength. The maximum tensile strength (16.7 MPa) was obtained at the applied stress of 1.2 MPa; the strength was within a range of control values. There was a similar correlation between applied stress and tangent modulus, and the modulus was maintained at control level under 1.3 MPa stress. The stress of 1.2 to 1.3 MPa is equivalent to approximately 50 percent of the peak stress developed in the intact rabbit patellar tendon by running. Strain at failure of cultured collagen fascicles was negatively correlated with applied stress, and that at 1.2 to 1.3 MPa stress was almost the same as the control value. Crimp morphology in the fascicles cultured under about 1.2 MPa stress was similar to that in control fascicles. These results indicate that cultured collagen fascicles change the mechanical properties and structure in response to static tensile stress. In addition, their mechanical properties and structure are maintained at control level if the static stress of 50 percent of in-vivo peak stress is applied.

Effect of carbon on the mechanical properties of maraging steel N18K9M5T

1972 ◽  
Vol 14 (3) ◽  
pp. 195-196
Author(s):  
N. I. Popova ◽  
S. Ya. Reznikova ◽  
V. A. Kharitonov ◽  
V. F. Shishov
Keyword(s):  
Mechanical Properties ◽  
Maraging Steel ◽  
Steel N18k9m5t ◽  
Maraging Steel N18k9m5t

Effect of silicon and titanium on the mechanical properties of steel N18K9M5T

1984 ◽  
Vol 26 (3) ◽  
pp. 232-234
Author(s):  
V. A. Kharitonov ◽  
N. I. Popova ◽  
V. F. Shishov
Keyword(s):  
Mechanical Properties ◽  
Steel N18k9m5t

Study on the Mechanical Properties and Creep Behaviour of Carbon Fiber Nano-Composites

2011 ◽  
Vol 284-286 ◽  
pp. 557-564 ◽  
Author(s):  
Yi Luen Li ◽  
Wei Jen Chen ◽  
Ming Yuan Shen ◽  
Chin Lung Chiang ◽  
Ming Chuen Yip
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Carbon Fiber ◽  
Epoxy Resin ◽  
Creep Strain ◽  
Applied Stress ◽  
Room Temperature ◽  
Electrical Conductivities ◽  
The Matrix ◽  
Creep Time

The surface modification of carbon nanotubes（CNTs）has been recently observed to influence the distribution of CNTs in epoxy resin and the mechanical properties and electrical conductivities of these CNTs. Accordingly, the treatment of CNTs to with organic acids to oxidize them generates functional groups on the surface of CNTs. This investigation studies the consequent enhancement of the mechanical properties and electrical conductivities of CNTs. The influence of adding various proportions of CNTs to the epoxy resin on the mechanical properties and electrical conductivities of the composites thus formed is investigated, and the strength of the material is tested at different temperatures. Moreover, the creep behavior of carbon fiber（CF）/epoxy resin thermosetting composites was tested analyzed at different stresses, orientations of fiber, temperatures and humidities. The creep exhibits only two stages- primary creep and steady-state creep. The effects of creep stress, creep time, and humidity on the creep of composites that contain various proportion of CNTs were investigated at various temperatures. However, increasing the number of cycles in cyclic creep tests at room temperature resulted in a decrease in creep strain even at a high temperature of 55°C. Possible room temperature creep mechanisms have been proposed and discussed. Creep strain is believed to increase with applied stress, creep time, humidity, temperature and degree of the angle θ between the orientation of fiber and the direction of the applied stress. The test results also indicate that mechanical strength and electrical conductivity increase with the amount of CNTs added to the composites. Different coefficients of expansion of the matrix, fiber and CNTs, are such that overexpansion of the matrix at high temperature results in cracking in it. An SEM image of the fracture surface reveals debonding and the pulling out of longitudinal fibers because of poor interfacial bonding between fiber and matrix, which reduce overall strength.

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