Rigorous analysis and pragmatic guidelines in estimating strain rate sensitivity using stress relaxation test

Prasad, Kali; Balaji, Vikram; Hariharan, K.; Phani, P. Sudharshan; Carlone, Pierpaolo

doi:10.1016/j.mechmat.2022.104279

Cited by 11 publications

(4 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This has been experimentally verified in many materials [19][20][21][22][23][24]. The improvement is primarily | https://mc03.manuscriptcentral.com/friction attributed to the combined effect of dislocation annihilation and homogenization of internal stress [25][26][27]. During HET, intermittent stopping of the conical punch during deformation is expected to delay the onset of fracture due to stress relaxation and improve HER.…”

Section: Introductionmentioning

confidence: 79%

Does friction contribute to formability improvement using servo press?

et al. 2023

Self Cite

View full text Add to dashboard Cite

Servo press forming machines are advanced forming systems that are capable of imparting interrupted punch motion, resulting in enhanced room temperature formability. The exact mechanism of the formability improvement is not yet established. The contribution of interrupted motion in the ductility improvement has been studied through stress relaxation phenomena in uniaxial tensile (UT) tests. However, the reason for improved formability observed when employing servo press is complicated due to the additional contribution from frictional effects. In the present work, an attempt is made to decouple the friction effect on formability improvement numerically. The improved formability is studied using a hole expansion test (HET). The limit of forming during hole expansion is modeled using the Hosford-Coulomb (HC) damage criteria, which is implemented as a user subroutine in a commercial explicit finite element (FE) software. Only the contribution of stress relaxation is accounted for in the evolution of the damage variable during interrupted loading. Therefore, the difference between simulation and experimental hole expansion ratio (HER) can be used to decouple the friction effect from the overall formability improvement during hole expansion. The improvement in HER due to stress relaxation and friction effect is different. The study showed that the model effectively captures the hole expansion deformation process in both monotonic and interrupted loading conditions. Compared to stress relaxation, friction effect played a major role during interrupted HET.

show abstract

Section: Introductionmentioning

confidence: 79%

Does friction contribute to formability improvement using servo press?

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Serrated deformation behavior is observed in the W-temper condition. This is characteristic of occurrence of Portevin−Le Chatelier effect (PLC) [3,17]. In the W-temper condition, solute elements present in the aluminum matrix, interact with the dislocations during plastic deformation resulting in the serrated flow behavior.…”

Section: Correlating: Her With Tensile Propertiesmentioning

confidence: 99%

“…In recent years, aluminum alloys have gained considerable attention in the automotive and aerospace industries for light weighting applications [1,2,3,4]. Among the various aluminum alloys, precipitate hardened aluminum alloys are widely used due to their high strength to weight ratio, good wear and corrosion resistance [1,5].…”

Section: Introductionmentioning

confidence: 99%

“…Among the various aluminum alloys, precipitate hardened aluminum alloys are widely used due to their high strength to weight ratio, good wear and corrosion resistance [1,5]. However, one of the major technological problem that restricts their widespread usage is their inferior room temperature formability, especially in precipitate hardened conditions [3,6]. To address these manufacturing challenges, the alloys are IOP Publishing doi:10.1088/1757-899X/1238/1/012038 2 often formed at elevated temperatures [7].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evaluation of hole expansion formability of high strength AA7075 alloy under varying temper conditions

Prasad

Ebrahim

Hariharan

et al. 2022

IOP Conf. Ser.: Mater. Sci. Eng.

Self Cite

View full text Add to dashboard Cite

There has been a widespread increase in the use of aluminum alloys in automotive industries for meeting ever-growing light-weighting requirements. However, edge formability is a critical manufacturing challenge that restricts their widespread use. Edge formability of sheet metal is determined using a hole expansion test (HET) and is evaluated by the hole expansion ratio (HER). The present study investigates the effect of temper conditions on the edge formability of AA7075 alloy sheets. Hole expansion tests were conducted in different temper such as W-temper (super saturated solid solution followed by water quenching), under aged (UA), and peak aged (PA) conditions. Two different hole preparation techniques, a punching and a drilling process, were used to prepare samples with varying edge conditions. The results demonstrate that the W-temper has the highest edge formability irrespective of hole edge conditions. Researchers have reported that uniaxial stress state prevails at the hole edge during the HET. Consequently, uniaxial tensile tests were conducted on for each temper condition and various tensile properties such as yield stress (YS), ultimate tensile strength (UTS), ratio of yield stress to ultimate tensile strength (YS/UTS) were determined to evaluate edge formability. Furthermore, microstructural and failure analysis of the failed specimens were performed to explain the deformation behavior during the HET.

show abstract

Evaluating the low-temperature performance of asphalt mixtures based on the contraction and relaxation properties

Sun,

Yi,

et al. 2024

Construction and Building Materials

View full text Add to dashboard Cite

Rigorous analysis and pragmatic guidelines in estimating strain rate sensitivity using stress relaxation test

Cited by 11 publications

References 54 publications

Does friction contribute to formability improvement using servo press?

Does friction contribute to formability improvement using servo press?

Evaluation of hole expansion formability of high strength AA7075 alloy under varying temper conditions

Evaluating the low-temperature performance of asphalt mixtures based on the contraction and relaxation properties

Contact Info

Product

Resources

About