Thermal Ratcheting of a Beam Element Having an Idealized Bauschinger Effect

1976 ◽  
Vol 98 (3) ◽  
pp. 264-271 ◽  
Author(s):  
T. M. Mulcahy
Keyword(s):  
Strain Hardening ◽  
Temperature Variation ◽  
Bauschinger Effect ◽  
Rectangular Cross Section ◽  
Beam Element ◽  
Operating Conditions ◽  
Hardening Material ◽  
Linear Temperature ◽  
Thermal Ratcheting ◽  
Breeder Reactors

Thermal ratcheting has been analytically investigated for a beam element subjected to a linear temperature variation across its solid rectangular cross section. A linear strain-hardening material response exhibiting an idealized Bauschinger effect was assumed. Formulas are given for the associated strain accumulation which are valid over a large range of strain hardening, temperature variation, temperature cycles, and axial load. Specific results are tabulated for the materials and operating conditions typically associated with liquid metal breeder reactors.

ELASTO-PLASTIC BUCKLING OF PRESTRESSED ARCHES

2002 ◽  
Vol 02 (03) ◽  
pp. 295-313
Author(s):  
AMIR MIRMIRAN ◽  
AMDE M. AMDE ◽  
ZEFANG XU
Keyword(s):  
Yield Strength ◽  
Strain Hardening ◽  
Beam Element ◽  
Fabrication Technique ◽  
Linear Strain ◽  
Plastic Buckling ◽  
Buckling Mode ◽  
Hardening Material ◽  
Straight Beam ◽  
Support Conditions

Intentional buckling as a fabrication technique for arch frameworks results in prestrains at every section of the arch, which in turn affect its strength and stability. A nonlinear corotational straight beam element with elastic, linear strain hardening material has been developed to study the elasto-plastic buckling of prestressed arches. The study indicates that for prestressed arches there is an interdependence between the slenderness and steepness ratios of the arch with the ratio of prestresses to the yield strength of the material, all of which control the magnitude and shape of buckling mode. While steeper arches are generally more stable in their elastic range, the effect of steepness ratio is reduced as the prestress exceeds 55% of the yield strength. Effects of loading and support conditions have also been considered. Although fixed supports result in more stable arches, their effectiveness depends on the steepness ratio and the level of prestresses. Finally, the effect of strain hardening on the plastic buckling of the arch is more pronounced for lower values of the plastic tangent modulus.

MANUFACTURE INVESTIGATION OF CARTRIDGE WITH BOTTOM-MOST PART FLANGE BY DIRECT EXTRUSION WITH COUNTERPUNCH. REPORT 18. EXPERIMENTAL CHECK OF THEORETICAL RESULTS FOR DIFFERENT HOLLOW RADIUSES AND BOTTOM-MOST PART THICKNESSES

2020 ◽  
Vol 0 (9) ◽  
pp. 16-23
Author(s):  
A. L. Vorontsov ◽  
◽  
I. A. Nikiforov ◽  
Keyword(s):  
Strain Hardening ◽  
Theoretical Calculations ◽  
High Accuracy ◽  
Geometric Parameters ◽  
Strength Characteristics ◽  
Experimental Check ◽  
Hardening Material ◽  
Direct Extrusion ◽  
Theoretical Results

The results of an experimental check of the obtained theoretical formulae allowing us to determine the most important parameters of extrusion cartridges with a counterpunch for different hollow radiuses and bottom-most part thicknesses are presented. Characteristics of used tools, geometric parameters of extrusion experiments, strength characteristics of deformed materials and lubricants are described in detail. Both strain-hardening material and strain-unhardening material were studied. Methodology of the theoretical calculations is demonstrated in detail. High accuracy of the obtained design formulae was confirmed.

scholarly journals On Computational Modelling Of Strain-Hardening Material Dynamics

2012 ◽  
Vol 11 (5) ◽  
pp. 1525-1546 ◽  
Author(s):  
Philip Barton ◽  
Evgeniy Romenski
Keyword(s):  
Relaxation Time ◽  
Stress Relaxation ◽  
Plastic Strain ◽  
Strain Hardening ◽  
Three Dimensional ◽  
Computational Modelling ◽  
Constitutive Models ◽  
Successful Implementation ◽  
Hardening Material ◽  
Dislocation Mechanics

AbstractIn this paper we show that entropy can be used within a functional for the stress relaxation time of solid materials to parametrise finite viscoplastic strain-hardening deformations. Through doing so the classical empirical recovery of a suitable irreversible scalar measure of work-hardening from the three-dimensional state parameters is avoided. The success of the proposed approach centres on determination of a rate-independent relation between plastic strain and entropy, which is found to be suitably simplistic such to not add any significant complexity to the final model. The result is sufficiently general to be used in combination with existing constitutive models for inelastic deformations parametrised by one-dimensional plastic strain provided the constitutive models are thermodynamically consistent. Here a model for the tangential stress relaxation time based upon established dislocation mechanics theory is calibrated for OFHC copper and subsequently integrated within a two-dimensional moving-mesh scheme. We address some of the numerical challenges that are faced in order to ensure successful implementation of the proposedmodel within a hydrocode. The approach is demonstrated through simulations of flyer-plate and cylinder impacts.

Torsion of a conical rod made of a strain-hardening material

1985 ◽  
Vol 17 (6) ◽  
pp. 801-805 ◽  
Author(s):  
A. A. Ostsemin ◽  
V. A. Lupin
Keyword(s):  
Strain Hardening ◽  
Hardening Material ◽  
Conical Rod

Solution to the Rolling Problem for a Strain-Hardening Material by the Method of Discontinuities

1951 ◽  
Vol 18 (1) ◽  
pp. 90-94
Author(s):  
Alice Winzer
Keyword(s):  
Strain Hardening ◽  
Method Of Characteristics ◽  
Continuous Solution ◽  
Discontinuous Solution ◽  
Yield Condition ◽  
Hardening Material ◽  
Discontinuity Surfaces ◽  
Plane Plastic ◽  
Thin Plastic ◽  
Good Agreement

Abstract The problem of drawing and rolling of a thin plastic sheet between cylindrical guides was investigated recently by H. I. Ansoff, under the assumption that the material is in a state of plane plastic flow and obeys the Saint Venant-Mises yield condition (1, 2). He determined the stress distribution along the sheet by the method of characteristics and also by the method of discontinuity surfaces and found good agreement between these results as well as with experimental data. Since the computations required for the discontinuous solution are considerably less laborious than those necessary for the continuous solution, the same type of problem, but now under the assumption that the material displays strain-hardening, will be analyzed by the method of discontinuities. It seems reasonable to expect that the results so found constitute a close approximation to results based upon a continuous solution.

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