Influence of Welding and Composition on the Short-Term Stable Crack Propagation Through Polyolefin Single- and Bilayered Structures

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F17%3A00506754" target="_blank" >RIV/68081723:_____/17:00506754 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/chapter/10.1007%2F978-3-319-41879-7_15" target="_blank" >https://link.springer.com/chapter/10.1007%2F978-3-319-41879-7_15</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/978-3-319-41879-7_15" target="_blank" >10.1007/978-3-319-41879-7_15</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Influence of Welding and Composition on the Short-Term Stable Crack Propagation Through Polyolefin Single- and Bilayered Structures

Popis výsledku v původním jazyce

The overall stable crack initiation and propagation behaviour of fracture mechanics specimens cut from plastic pipes that were composed of different polyolefin materials were investigated using concepts of elastic plastic fracture mechanics including the crack propagation kinetics. The effect of specimen shape, orientation, welding and lading rate on the crack resistance (R) behaviour of these materials has been thereby assessed. It was found in principle that specimen shape, orientation and welding have an influence indeed but only an unexpected small one on crack initiation behaviour and, particularly, on crack propagation behaviour. The crack initiation toughness is not sensitive to the orientation in most cases. In contrast, the crack propagation toughness is significantly affected by the orientation where the values for crack propagation in extrusion direction are larger than ones for crack propagation crosswise to that. This confirms that the morphology affects the stable crack propagation behaviour more than the stable crack initiation behaviour. In agreement with results of the microindentation test, fracture mechanics investigations also show that a lower welding pressure and a larger welding temperature, respectively, have no or a positive effect on the mechanical and fracture mechanics properties, whereas a larger pressure and a lower temperature, respectively, result in deterioration of the performance of the welded joint. Furthermore, the R-curve behaviour was investigated using specimens cut from bilayer pipe segments. It has been shown that an additional layer has a clear impact on the R-curve behaviour compared to the crack propagation in single-layer pipes, which can be explained thereby that the plastic constraint was affected by this additional layer. For clarification of the toughness-in- or-decreasing effect of an additional layer (with differing mechanical characteristics) on the layer where the crack was growing, R-curve ratios were introduced, that showed that the asymmetric mechanical properties of different layers were directly reflected in an asymmetric impact on the stable crack initiation and propagation behaviour.

Název v anglickém jazyce

Influence of Welding and Composition on the Short-Term Stable Crack Propagation Through Polyolefin Single- and Bilayered Structures

Popis výsledku anglicky

The overall stable crack initiation and propagation behaviour of fracture mechanics specimens cut from plastic pipes that were composed of different polyolefin materials were investigated using concepts of elastic plastic fracture mechanics including the crack propagation kinetics. The effect of specimen shape, orientation, welding and lading rate on the crack resistance (R) behaviour of these materials has been thereby assessed. It was found in principle that specimen shape, orientation and welding have an influence indeed but only an unexpected small one on crack initiation behaviour and, particularly, on crack propagation behaviour. The crack initiation toughness is not sensitive to the orientation in most cases. In contrast, the crack propagation toughness is significantly affected by the orientation where the values for crack propagation in extrusion direction are larger than ones for crack propagation crosswise to that. This confirms that the morphology affects the stable crack propagation behaviour more than the stable crack initiation behaviour. In agreement with results of the microindentation test, fracture mechanics investigations also show that a lower welding pressure and a larger welding temperature, respectively, have no or a positive effect on the mechanical and fracture mechanics properties, whereas a larger pressure and a lower temperature, respectively, result in deterioration of the performance of the welded joint. Furthermore, the R-curve behaviour was investigated using specimens cut from bilayer pipe segments. It has been shown that an additional layer has a clear impact on the R-curve behaviour compared to the crack propagation in single-layer pipes, which can be explained thereby that the plastic constraint was affected by this additional layer. For clarification of the toughness-in- or-decreasing effect of an additional layer (with differing mechanical characteristics) on the layer where the crack was growing, R-curve ratios were introduced, that showed that the asymmetric mechanical properties of different layers were directly reflected in an asymmetric impact on the stable crack initiation and propagation behaviour.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20306 - Audio engineering, reliability analysis

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

DEFORMATION AND FRACTURE BEHAVIOUR OF POLYMER MATERIALS

ISSN

0933-033X

e-ISSN

—

Svazek periodika

247

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

17

Strana od-do

211-227

Kód UT WoS článku

000430004400016

EID výsledku v databázi Scopus

2-s2.0-85024473658