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Experimental Study of Yield Surface in Polypropylene Considering Rate Effect: Stress Path Dependence
Hang Zheng1, Xiaofei Yi1, Zhiping Tang1
1CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027, China.
Polymers
|August 12, 2022
Summary
Polypropylene
Area of Science:
- Materials Science
- Mechanical Engineering
- Polymer Science
Background:
- Polypropylene (PP) is a widely used polymer with complex mechanical behavior.
- Understanding its yield surface evolution under dynamic impact is crucial for engineering applications.
- Dynamic loading conditions significantly influence material properties, necessitating specialized investigation.
Purpose of the Study:
- To investigate the dynamic yield surface evolution of polypropylene (PP).
- To determine the relationship between yield surface parameters and strain rate under dynamic impact.
- To analyze the mechanical response of PP under combined compression-shear loading.
Main Methods:
- Utilized five shear-compression specimens (SCSs) with varying inclination angles.
- Employed the split Hopkinson pressure bar (SHPB) to achieve dynamic combined stress loading paths.
- Analyzed the evolution of compressive and shear stresses during PP SCS deformation.
Main Results:
- Identified a three-stage deformation transition in PP: unyield→yield→failure.
- Established that PP's yield characteristics are influenced by hydrostatic pressure and stress path.
- Obtained the dynamic yield surface and model parameters using the Hu-Pae yield criterion.
Conclusions:
- Ascertained the strain rate dependency of PP's dynamic yield surface.
- Provided insights into the visco-elastic-plastic mechanical response of PP under dynamic combined loading.
- Contributed to a deeper understanding of PP-based material behavior under impact conditions.
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