The effect of creep at elevated temperatures on internal friction and elastic modulus of metals

1959 ◽  
Vol 1 (12) ◽  
pp. 27-33
Author(s):  
I. A. Oding ◽  
M. G. Lozinskii ◽  
L. K. Gordienko
1985 ◽  
Vol 46 (C10) ◽  
pp. C10-395-C10-398
Author(s):  
S. PILECKI ◽  
J. KRÓLIKOWSKI ◽  
R. JEMIELNIAK

The analysis of the previous results of the study on concrete stress-strain behavior at elevated temperatures has been carried out. Based on the analysis, the main reasons for strength retrogression and elastic modulus reduction of concrete have been identified. Despite a significant amount of research in this area, there is a large spread in experimental data received, both as a result of compression and tension. In addition, the deformation characteristics of concrete are insufficiently studied: the coefficient of transverse deformation, the limiting relative compression deformation corresponding to the peak load and the almost complete absence of studies of complete deformation diagrams at elevated temperatures. The two testing chambers provided creating the necessary temperature conditions for conducting studies under bending compression and tension have been developed. On the basis of the obtained experimental data of physical and mechanical characteristics of concrete at different temperatures under conditions of axial compression and tensile bending, conclusions about the nature of changes in strength and deformation characteristics have been drawn. Compression tests conducted following the method of concrete deformation complete curves provided obtaining diagrams not only at normal temperature, but also at elevated temperature. Based on the experimental results, dependences of changes in prism strength and elastic modulus as well as an equation for determining the relative deformation and stresses at elevated temperatures at all stages of concrete deterioration have been suggested.


1981 ◽  
Vol 13 (11) ◽  
pp. 1393-1396
Author(s):  
T. G. Kovaleva ◽  
A. D. Shevchuk ◽  
P. I. Tereshchenko

1976 ◽  
Vol 33 (1) ◽  
pp. 338-344 ◽  
Author(s):  
J. M. Pelletier ◽  
R. Borrelly ◽  
P. F. Gobin

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1890
Author(s):  
Anton I. Tagiltsev ◽  
Elena Y. Panchenko ◽  
Ekaterina E. Timofeeva ◽  
Yuriy I. Chumlyakov ◽  
Ekaterina S. Marchenko ◽  
...  

This study investigated the effect of stress-induced martensite aging under tensile and compressive stresses on the functional and viscoelastic properties in Ni50.3Ti32.2Hf17.5 polycrystals containing dispersed H-phase particles up to 70 nm in size obtained by preliminary austenite aging at 873 K for 3 h. It was found that stress-induced martensite aging at 428 K for 12 h results in the appearance of a two-way shape memory effect of −0.5% in compression and +1.8% in tension. Moreover, a significant change in viscoelastic properties can be observed: an increase in internal friction (by 25%) and a change in elastic modulus in tensile samples. The increase in internal friction during martensitic transformation after stress-induced martensite aging is associated with the oriented growth of thermal-induced martensite. After stress-induced martensite aging, the elastic modulus of martensite (EM) increased by 8 GPa, and the elastic modulus of austenite (EA) decreased by 8 GPa. It was shown that stress-induced martensite aging strongly affects the functional and viscoelastic properties of material and can be used to control them.


2011 ◽  
Author(s):  
M. Freels ◽  
P. K. Liaw ◽  
E. Garlea ◽  
J. S. Morrell ◽  
M. Radiovic

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Qifang Xie ◽  
Lipeng Zhang ◽  
Shenghua Yin ◽  
Baozhuang Zhang ◽  
Yaopeng Wu

Fires are always known for seriously deteriorating concrete in structures, especially for those with certain carbonation due to long-time service. In this paper, 75 prism specimens were prepared and divided into four groups (three carbonated groups and one uncarbonated group). Specimens were tested under different temperatures (20, 300, 400, 500, 600, and 700°C), exposure times (3, 4, and 6 hours), and cooling methods (water and natural cooling). Surface characteristics, weight loss rate, and residual mechanical properties (strength, initial elastic modulus, peak, and ultimate compressive strains) of carbonated concrete specimens after elevated temperatures were investigated and compared with that of the uncarbonated ones. Results show that the weight loss rates of the carbonated concrete specimens are slightly lower than that of the uncarbonated ones and that the cracks are increased with raising of temperatures. Surface colors of carbonated concrete are significantly changed, but they are not sensitive to cooling methods. Surface cracks can be evidently observed on carbonated specimens when temperature reaches 400°C. Residual compressive strength and initial elastic modulus of carbonated concrete after natural cooling are generally larger than those cooled by water. The peak and ultimate compressive strains of both carbonated and uncarbonated concrete specimens increase after heating, but the values of the latter are greater than that of the former. Finally, the constitutive equation to predict the compressive behaviors of carbonated concrete after high temperatures was established and validated by tests.


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