Tension—compression behaviour of annealed oxygen-free high-conductivity copper after strain cycling in the plastic range

1975 ◽  
Vol 10 (1) ◽  
pp. 10-18 ◽  
Author(s):  
P W J Oldroyd

When copper is cycled between fixed limits of strain it ends towards a settled cyclic state. The two curves which form the tension-compression stress-strain loop will have the same shape but, no matter what point is chosen on the loop for the return to zero stress, the material will not be left with symmetrical tension-compression properties. This is because of the Bauschinger effect. It is demonstrated that the Bauschinger effect can be eliminated by cycling down to zero stress and zero strain using progressively decreasing strain amplitudes. Relatively few cycles suffice and, when the strain range is small, the structural strain-hardening effect is not noticeably reduced. Even with the largest range investigated (± 1 per cent plastic strain) the structural resoftening is slight. The significance of the subsequent tension and compression stress-strain curves is discussed.

2004 ◽  
Vol 1-2 ◽  
pp. 133-138 ◽  
Author(s):  
G. Urriolagoitia-Sosa ◽  
J.F. Durodola ◽  
N.A. Fellows

A new inverse method has been developed for the simultaneous derivation of tensile and compressive stress strain behaviour from bending tests only. This new procedure can be applied to materials having asymmetric tensile and compressive stress strain behaviour and also materials that have been previously strain hardened (Bauschinger Effect). This paper presents results obtained using the new method and compares them with experimentally obtained tensile and compressive stress strain curves. The agreement of the derived stress strain data in tension and compression is encouraging.


2011 ◽  
Vol 314-316 ◽  
pp. 1377-1382
Author(s):  
David Torres Franco ◽  
Guillermo Urriolagoitia-Sosa ◽  
Guillermo Urriolagoitia-Calderón ◽  
Luis Hector Hernandez Gomez ◽  
Beatriz Romero Angeles ◽  
...  

Until now, the most common way to obtain the stress-strain curves for a material is through axial tensile testing. However, in recent years there have been developments on alternative methods for material characterization. In this sense, the bending procedure has proved to be a powerful technique, which allows simultaneous determination of tension and compression stress behavior by the use of bending moment and strain data. The characterization of materials by means of bending data was presented for the first time in 1910 by the German engineer Herbert. Some years later Nadai and Marin developed some research on this procedure. More recently, several researchers (Mayville and Finnie, Laws and Urriolagoitia-Sosa, et.al.) have developed diverse bending methods for the simultaneous determination of tension and compression stress-strain curves. In this paper, three bending methods are analyzed and compared against axial tensile and compressive results. It was decided to apply each one of the bending procedures to bent rectangular cross sections beams made from 6063-T5 Aluminum alloy. The specimens were annealed to eliminate previous loading history and axially pulled to induce a controlled anisotropic behavior (strain hardening and Bauschinger effect). The results obtained by two of the three methods provided great confidence and have certified the application of this new technique to characterize material.


Author(s):  
A Nayebi ◽  
H Rokhgireh ◽  
M Araghi ◽  
M Mohammadi

Additively manufactured parts often comprise internal porosities due to the manufacturing process, which needs to be considered in modelling their mechanical behaviour. It was experimentally shown that additively manufactured parts’ tensile and compressive mechanical properties are different for various metallic alloys. In this study, isotropic continuum damage mechanics is used to model additively manufactured alloys’ tension and compression behaviours. Compressive stress components can shrink discontinuities present in additively manufactured alloys. Therefore, the crack closure effect was employed to describe different behaviours during uniaxial tension and compression tests. A finite element model embedded in an ABAQUS’s UMAT format was developed to account for the isotropic continuum damage mechanics model. The numerical results of tension and compression tests were compared with experimental observations for additively manufactured maraging steel, AlSi10Mg and Ti-6Al-4V. Stress–strain curves in tension and compression of these alloys were obtained using the continuum damage mechanics model and compared well with the experimental results.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1393
Author(s):  
Xiaochang Duan ◽  
Hongwei Yuan ◽  
Wei Tang ◽  
Jingjing He ◽  
Xuefei Guan

This study develops a general temperature-dependent stress–strain constitutive model for polymer-bonded composite materials, allowing for the prediction of deformation behaviors under tension and compression in the testing temperature range. Laboratory testing of the material specimens in uniaxial tension and compression at multiple temperatures ranging from −40 ∘C to 75 ∘C is performed. The testing data reveal that the stress–strain response can be divided into two general regimes, namely, a short elastic part followed by the plastic part; therefore, the Ramberg–Osgood relationship is proposed to build the stress–strain constitutive model at a single temperature. By correlating the model parameters with the corresponding temperature using a response surface, a general temperature-dependent stress–strain constitutive model is established. The effectiveness and accuracy of the proposed model are validated using several independent sets of testing data and third-party data. The performance of the proposed model is compared with an existing reference model. The validation and comparison results show that the proposed model has a lower number of parameters and yields smaller relative errors. The proposed constitutive model is further implemented as a user material routine in a finite element package. A simple structural example using the developed user material is presented and its accuracy is verified.


Sign in / Sign up

Export Citation Format

Share Document