Publication detail

Local experimental determination of material characteristics for polymers related to fem analysis

DOBEŠ, M. VRBKA, J.

Czech title

Local experimental determination of material characteristics for polymers related to fem analysis

English title

Local experimental determination of material characteristics for polymers related to fem analysis

Type

journal article - other

Language

en

Original abstract

Polymer materials exhibit a high ductility. Determination of the yield strain as well as the break (ultimate) strain is usually done on the basis of tensile tests performed on standard samples and evaluated for normalized measured length, supposing the homogeneous material deformation along the sample axis. This experimental approach does not take into account the plastic strain concentration in small neck area during the final deformation phase before the sample rupture, what is typical for the plastics behavior. Application of so defined material characteristic in the case of Finite element method (FEM) analyses of real constructions made of TSCP plastics (typical semi-crystal polymer) led to significantly conservative (smaller) values of ultimate loads compared to the measured ones. A special experimental method making use of high-speed camera has been developed to determine the strain in defined small area of local strain concentration being also in correlation with the FEM element size. Application of the more realistic (higher local) break strain value in the case of FEM analyses of real TSCP constructions led to much better agreement between the calculated and measured stiffness and ultimate load values.

Czech abstract

Polymer materials exhibit a high ductility. Determination of the yield strain as well as the break (ultimate) strain is usually done on the basis of tensile tests performed on standard samples and evaluated for normalized measured length, supposing the homogeneous material deformation along the sample axis. This experimental approach does not take into account the plastic strain concentration in small neck area during the final deformation phase before the sample rupture, what is typical for the plastics behavior. Application of so defined material characteristic in the case of Finite element method (FEM) analyses of real constructions made of TSCP plastics (typical semi-crystal polymer) led to significantly conservative (smaller) values of ultimate loads compared to the measured ones. A special experimental method making use of high-speed camera has been developed to determine the strain in defined small area of local strain concentration being also in correlation with the FEM element size. Application of the more realistic (higher local) break strain value in the case of FEM analyses of real TSCP constructions led to much better agreement between the calculated and measured stiffness and ultimate load values.

English abstract

Polymer materials exhibit a high ductility. Determination of the yield strain as well as the break (ultimate) strain is usually done on the basis of tensile tests performed on standard samples and evaluated for normalized measured length, supposing the homogeneous material deformation along the sample axis. This experimental approach does not take into account the plastic strain concentration in small neck area during the final deformation phase before the sample rupture, what is typical for the plastics behavior. Application of so defined material characteristic in the case of Finite element method (FEM) analyses of real constructions made of TSCP plastics (typical semi-crystal polymer) led to significantly conservative (smaller) values of ultimate loads compared to the measured ones. A special experimental method making use of high-speed camera has been developed to determine the strain in defined small area of local strain concentration being also in correlation with the FEM element size. Application of the more realistic (higher local) break strain value in the case of FEM analyses of real TSCP constructions led to much better agreement between the calculated and measured stiffness and ultimate load values.

Keywords in Czech

polymer, experiment, break limit, FEM analysis, high-speed camera

Keywords in English

polymer, experiment, break limit, FEM analysis, high-speed camera

RIV year

2014

Released

25.02.2014

Publisher

Association for Engineering Mechanics

Location

Praha

ISSN

1802-1484

Volume

21

Number

3

Pages from–to

151–158

Pages count

8

BIBTEX


@article{BUT108956,
  author="Martin {Dobeš} and Jan {Vrbka},
  title="Local experimental determination of material characteristics for polymers related to fem analysis",
  year="2014",
  volume="21",
  number="3",
  month="February",
  pages="151--158",
  publisher="Association for Engineering Mechanics",
  address="Praha",
  issn="1802-1484"
}