Formation of a regular relief during self-oscillating neck propagation

Баженов, С. Л.; Rodionova, Yu. A.; Sinevich, E. A.; Kechek’yan, A. S.; Rogozinskii, A. K.

doi:10.1134/s1560090406050095

Cited by 3 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under certain testing conditions, some linear polymers exhibit unusual self-excited oscillation during the neck propagation, i.e., a non-uniform necking accompanied with periodical stress fluctuation. [1][2][3][4] Stress oscillation (SO), occurs when necking is no longer constant during elongation. It can be seen in amorphous and semi-crystalline polymers during cold drawing and is characterised by obvious periodic formation of transparent and opaque banding perpendicular to the deformation direction.…”

Section: Introductionmentioning

confidence: 99%

“…It can be seen in amorphous and semi-crystalline polymers during cold drawing and is characterised by obvious periodic formation of transparent and opaque banding perpendicular to the deformation direction. The SO and instability of necking have been observed in a number of thermoplastic polymers, such as amorphous polyethyleneterephthalate (aPET), 2,5-9 copolyesters, 10 high density polyethylene (HDPE), 1,11 syndiotactic polypropylene (sPP) 8,[12][13][14] and polyamide 1,15,16 at room temperature, and polycarbonate (PC) at elevated temperatures. 17 The SO mechanism is under debate although, it was proposed that the mechanical work was converted into thermal energy which generated local heat instability in the neck region of the polymer sample.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stress-oscillation behaviour of semi-crystalline polymers: the case of poly(butylene succinate)

et al. 2018

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Stress-oscillation behaviour of semi-crystalline polymers: the case of poly(butylene succinate)

et al. 2018

View full text Add to dashboard Cite

show abstract

“…In PET and PVC, the critical length is 5–30 mm; while for PP and HDPE, it is 0.9 and 7 m, respectively 7. The critical length for PP and HDPE is so high that oscillations are observed only if a sample is tested in consequence with a spring.…”

Section: Introductionmentioning

confidence: 99%

“…The oscillatory neck propagation is rather general phenomenon observed in different linear polymers. For example, in PET, PVC, PA‐6, PP, and HDPE 7. However, the critical sample length of appearance of oscillations depends on polymer.…”

Section: Introductionmentioning

confidence: 99%

Self‐oscillatory neck propagation in polymers

Баженов¹

2010

J of Applied Polymer Sci

View full text Add to dashboard Cite

The oscillatory neck propagation during cold drawing of PET was studied. The mechanism of selfoscillations is heat instability of neck propagation. Oscillations are observed at high velocities when the draw stress increases with an increase in cross-head speed. Neck propagation is described by three equations, which were solved numerically. The solution of these equations predicts appearance of oscillations at high elongation velocities in agreement with experimental observations. The necessary condition of appearance of oscillations in any polymer is existence of some interval of cross-head speeds V, where the draw stress decreases with an increase in V.

show abstract

Effect of cellular uniformity on the necking propagation of foam injection Molded PP/HDPE blend parts

Zhou

Cao

Cheng

2020

J of Applied Polymer Sci

View full text Add to dashboard Cite

Necking propagation (NP) is an important phenomenon that is facilitated by the superductility of many materials, although necking is often considered to be a type of unstable and heterogeneous deformation under tensile loading. In this study, the NP of samples produced with injection molding of polypropylene (PP) and high‐density polyethylene (HDPE) blends with or without a blowing agent was investigated by standard tensile testing, and the foam morphology and cellular structure were characterized with scanning electron microscopy. It was found that the foam parts fabricated with the PP/HDPE blends had the ability to be superductile under a low tensile test speed, which was attributed to the necking spreading throughout the tested gauge section stably and reliably. However, the NP of the foam PP/HDPE blend samples strongly depended on the distribution of the cellular foam. To investigate the relationship between the cellular structure and NP, a design of experiment approach based on the Taguchi method was used to fabricate many samples with different foam structures. The tensile test results of these samples suggested that the cellular uniformity, which was determined based on the statistical results of the fracture surface morphology, played an important role in the NP. The results suggested that there is a close relationship between the NP and the cellular uniformity. Using nonlinear fitting, it was straightforward to obtain a model between the NP length and cellular uniformity index for PP/HDPE molded foam parts.

show abstract

Formation of a regular relief during self-oscillating neck propagation

Cited by 3 publications

References 1 publication

Stress-oscillation behaviour of semi-crystalline polymers: the case of poly(butylene succinate)

Stress-oscillation behaviour of semi-crystalline polymers: the case of poly(butylene succinate)

Self‐oscillatory neck propagation in polymers

Effect of cellular uniformity on the necking propagation of foam injection Molded PP/HDPE blend parts

Contact Info

Product

Resources

About