Determination of two key parameters of a cohesive zone model for pipeline steels based on uniaxial stress-strain curve

2016 ◽  
Vol 163 ◽  
pp. 55-65 ◽  
Author(s):  
Y.J. Wang ◽  
C.Q. Ru
1986 ◽  
Vol 18 (5) ◽  
pp. 664-668
Author(s):  
M. V. Shakhmatov ◽  
V. V. Erofeev ◽  
V. A. Lupin ◽  
A. A. Ostsemin

2016 ◽  
Vol 258 ◽  
pp. 157-160 ◽  
Author(s):  
Jiří Vala

Computational modelling of the crack growth in brittle and quasi-brittle materials used in mechanical, civil, etc. engineering applies the cohesive zone model with various traction separation laws; determination of micro-mechanical parameters comes then from static tests, microscopic observation and numerical calibration. Although most authors refer to ill-possedness and need of artificial regularization in inverse problems (identification of material parameters), some difficulties originate even in nonlinear formulations of direct and sensitivity problems. This paper demonstrates the possibility of proper analysis of the existence of a weak solution and of the convergence of a corresponding numerical algorithm for such model problem, avoiding non-physical assumptions.


1950 ◽  
Vol 23 (3) ◽  
pp. 576-580 ◽  
Author(s):  
Thomas G. Fox ◽  
Paul J. Flory ◽  
Robert E. Marshall

Abstract Experimental determination of the elongation at which crystallization commences in vulcanized rubber has been attempted through measurement of density changes by a hydrostatic method. The critical elongation for incipient crystallization appears to depend on the temperature, in approximate accordance with theoretical prediction. Crystallization sets in at an elongation well below that at which the stress-strain curve assumes a steep slope.


2004 ◽  
Vol 841 ◽  
Author(s):  
Karsten Durst ◽  
Björn Backes ◽  
Mathias Göken

ABSTRACTThe determination of plastic properties of metallic materials by nanoindentation requires the analysis of the indentation process and the evaluation methods. Particular effects on the nanoscale, like the indentation size effect or piling up of the material around the indentation, need to be considered. Nanoindentation experiments were performed on conventional grain sized (CG) as well as on ultrafine-grained (UFG) copper and brass. The indentation experiments were complemented with finite element simulations using the monotonic stress-strain curve as input data. All indentation tests were carried out using cube-corner and Berkovich geometry and thus different amount of plastic strain was applied to the material, according to Tabors theory. We find an excellent agreement between simulations and experiments for the UFG materials from which a representative strain of εB ≈ 0.1 and εcc ≈ 0.2 is determined. With these data, the slope of the stress-strain curve is predicted for all materials down to an indentation depth of 800 nm.


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