Loading Rate Sensitivity of the Essential Work of Fracture, a Case Study on Pure Polypropylene

2016 ◽  
Vol 22 ◽  
pp. 7-13
Author(s):  
Sedigheh Pirsalami ◽  
Seyed Mojtaba Zebarjad ◽  
Zahra Zeinali
Keyword(s):  
Loading Rate ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Specific Work ◽  
Essential Work ◽  
Essential Work Of Fracture ◽  
Regular Trend ◽  
Toughness Evaluation ◽  
Work Of Fracture

The essential work of fracture (EWF) method is gaining attention for the toughness evaluation of ductile polymers. However its establishment as a toughness criteria requires that the parameters influencing it and their extent of influence be identified. In the current study the effect of the loading rate on the EWF of pure polypropylene (PP) is investigated. Tensile tests are performed at room temperature on DENT samples with ligament lengths of 7 to 15 mm at loading rates of 2 to 32 mm/min. The results confirm the dependency of the EWF on the loading rate, though a regular trend is not observed. The nonregularity of the EWF on the loading rate is explained by the ligament dependency of the loading rate effect on the specific work of fracture. This study reveals that the similarity of the ligament lengths and loading rate are necessities to yielding comparable values of the EWF.

scholarly journals Fracture Resistance of Advanced High-Strength Steel Sheets for Automotive Applications

2021 ◽  
Author(s):  
D. Frómeta ◽  
A. Lara ◽  
L. Grifé ◽  
T. Dieudonné ◽  
P. Dietsch ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Fracture Resistance ◽  
High Strength ◽  
Tensile Tests ◽  
Essential Work ◽  
Automotive Applications ◽  
Advanced High Strength Steel ◽  
Thickness Strain ◽  
Essential Work Of Fracture ◽  
Work Of Fracture

AbstractThe fracture resistance of different advanced high-strength steel (AHSS) sheets for automotive applications is investigated through conventional tensile tests, fracture toughness measurements, and hole expansion tests. Different fracture-related parameters, such as the true fracture strain (TFS), the true thickness strain (TTS), the fracture toughness at crack initiation (w e i ), the specific essential work of fracture (we), and the hole expansion ratio (HER), are assessed. The specific essential work of fracture (we) is shown to be a suitable parameter to evaluate the local formability and fracture resistance of AHSS. The results reveal that fracture toughness cannot be estimated from any of the parameters derived from tensile tests and show the importance of microstructural features on crack propagation resistance. Based on the relation fracture toughness-local formability, a new AHSS classification mapping accounting for global formability and cracking resistance is proposed. Furthermore, a physically motivated fracture criterion for edge-cracking prediction, based on thickness strain measurements in fatigue pre-cracked DENT specimens, is proposed.

scholarly journals Essential work of fracture assessment of acrylonitrile butadiene styrene (ABS) processed via fused filament fabrication additive manufacturing

2021 ◽  
Author(s):  
Pawan Verma ◽  
Jabir Ubaid ◽  
Andreas Schiffer ◽  
Atul Jain ◽  
Emilio Martínez-Pañeda ◽  
...  
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Essential Work ◽  
Fused Filament Fabrication ◽  
Essential Work Of Fracture ◽  
Fracture Properties ◽  
Raster Angle ◽  
3D Printed ◽  
Printing Direction ◽  
Work Of Fracture ◽  
Butadiene Styrene

AbstractExperiments and finite element (FE) calculations were performed to study the raster angle–dependent fracture behaviour of acrylonitrile butadiene styrene (ABS) thermoplastic processed via fused filament fabrication (FFF) additive manufacturing (AM). The fracture properties of 3D-printed ABS were characterized based on the concept of essential work of fracture (EWF), utilizing double-edge-notched tension (DENT) specimens considering rectilinear infill patterns with different raster angles (0°, 90° and + 45/− 45°). The measurements showed that the resistance to fracture initiation of 3D-printed ABS specimens is substantially higher for the printing direction perpendicular to the crack plane (0° raster angle) as compared to that of the samples wherein the printing direction is parallel to the crack (90° raster angle), reporting EWF values of 7.24 kJ m−2 and 3.61 kJ m−2, respectively. A relatively high EWF value was also reported for the specimens with + 45/− 45° raster angle (7.40 kJ m−2). Strain field analysis performed via digital image correlation showed that connected plastic zones existed in the ligaments of the DENT specimens prior to the onset of fracture, and this was corroborated by SEM fractography which showed that fracture proceeded by a ductile mechanism involving void growth and coalescence followed by drawing and ductile tearing of fibrils. It was further shown that the raster angle–dependent strength and fracture properties of 3D-printed ABS can be predicted with an acceptable accuracy by a relatively simple FE model considering the anisotropic elasticity and failure properties of FFF specimens. The findings of this study offer guidelines for fracture-resistant design of AM-enabled thermoplastics. Graphical abstract

Effects of thickness on the specific essential work of fracture of rigid PVC

1996 ◽  
Vol 36 (20) ◽  
pp. 2534-2541 ◽  
Author(s):  
G. Levita ◽  
L. Parisi ◽  
A. Marchetti ◽  
L. Bartolommei
Keyword(s):  
Essential Work ◽  
Essential Work Of Fracture ◽  
Rigid Pvc ◽  
Work Of Fracture

Effect of strain rate on the fracture toughness of some ductile polymers using the essential work of fracture (EWF) approach

2000 ◽  
Vol 40 (12) ◽  
pp. 2558-2568 ◽  
Author(s):  
Emma C. Y. Ching ◽  
Wendy K. Y. Poon ◽  
Robert K. Y. Li ◽  
Yiu-Wing Mai
Keyword(s):  
Fracture Toughness ◽  
Strain Rate ◽  
Essential Work ◽  
Essential Work Of Fracture ◽  
Work Of Fracture

Essential work of fracture analysis of the tearing of a ductile polymer film

2010 ◽  
Vol 77 (14) ◽  
pp. 2654-2661 ◽  
Author(s):  
A.B. Martínez ◽  
A. Segovia ◽  
J. Gamez-Perez ◽  
M.Ll. Maspoch
Keyword(s):  
Polymer Film ◽  
Fracture Analysis ◽  
Essential Work ◽  
Essential Work Of Fracture ◽  
Ductile Polymer ◽  
Work Of Fracture
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