An experimental study of the mechanical behavior of fused‐deposition (FD) ABS plastic materials is described. Elastic moduli and strength values are determined for the ABS monofilament feedstock and various unidirectional FD‐ABS materials. The results show a reduction of 11 to 37 per cent in modulus and 22 to 57 per cent in strength for FD‐ABS materials relative to the ABS monofilament. These reductions occur due to the presence of voids and a loss of molecular orientation during the FD extrusion process. The results can be used to benchmark computational models for stiffness and strength as a function of the processing parameters for use in computationally optimizing the mechanical performance of FD‐ABS materials in functional applications.

Mechanical behavior of acrylonitrile butadiene styrene (ABS) fused deposition materials. Experimental investigation

Fracture behavior of additively manufactured acrylonitrile butadiene styrene (ABS) materials

Increased fracture toughness of additively manufactured amorphous thermoplastics via thermal annealing

Interlayer adhesion and fracture resistance of polymers printed through melt extrusion additive manufacturing process

Fracture characterization of PC/ABS blends: effect of reactive compatibilization, ABS type and rubber concentration

The fracture toughness of acrylonitrile-butadiene-styrene (ABS) was determined by three J-integral methods, ASTM E813-81, E813-87, and by hysteresis. The critical J values (J 1c ) obtained are fairly independent of the specimen thickness, ranging from 10 to 15 mm. ASTM E813-81 and hysteresis methods result in comparable J 1c values, whereas the ASTM E813-87 was ∼ 40% to 50% higher. The critical displacement determined from the plots of hysteresis (energy or ratio) and the true crack grow length vs. displacement are close. This indicates the critical displacement determined by the hysteresis method is indeed the displacement at onset of crack initiation, and the corresponding J 1c represents a physical event of crack initiation. The elastic storage energy, the input energy minus the hysteresis energy, is the most important factor in determining the onset of crack initiation. The critical elastic storage energy (at the beginning of crack growth) was found close to the J 1c obtained from the E813-81 or the hvsteresis method.

https://ir.nctu.edu.tw/bitstream/11536/1742/1/A1995RX60000002.pdf

Fracture-toughness of acrylonitrile-butadiene-styrene by j-integral methods

Three J-integral methods and their modified versions have been used to characterize the fracture toughness of high-impact polystyrene (HIPS) with different thicknesses. The Jc values obtained were highest from the E813–87 method, followed by the E813–81 method, then by the hysteresis method. The hysteresis method based on the steep rising of hysteresis energy under constant displacement-controlled loading in Jc determination has many advantages over the ASTM E813–81 or the E813–87 method. The requirement of crack growth length measurements is no longer necessary and the controversial issue on the crack blunting line can also be avoided. The E813–87 method resulted in significantly higher Jc values for polymers, but the modified version of E813–87, by moving the offset line from the original 0.2 to 0.1 mm, resulted in comparable Jc values. Since crazes as the main failure mechanism for HIPS, well-defined crack blunting does not expect to occur and the Jc obtained by the original E813–81 based on the theoretically predicted blunting line is indeed slightly higher. The modified version of E813–81 by neglecting the blunting line in Jc determination is believed to be more reasonable for HIPS. The nature of polymers will determine whether the crack tip will be blunted, partially blunted, or not blunted. ASTM E813–81 is appropriate for those polymers with a well-defined blunted crack tip (such as elastomer-modified polycarbonate), whereas the modified version of ASTM E813–81 seems better for those polymers with craze as the main failure mechanism (such as HIPS). Experimental results indicated that this hysteresis method is able to inherently adjust the crack blunting effect and therefore can be applied to any type of ductile polymer. © 1993 John Wiley & Sons, Inc.

https://ir.nctu.edu.tw:443/bitstream/11536/3088/1/A1993KL82600017.pdf

Fracture toughness of high‐impact polystyrene based on three j‐integral methods

https://ir.nctu.edu.tw:443/bitstream/11536/1057/1/A1996VH16700009.pdf

Elastic-plastic fracture toughness of PC/ABS blend based on CTOD and J-integral methods

https://ir.nctu.edu.tw:443/bitstream/11536/1877/1/A1995RF98300007.pdf

Fracture toughness of a polycarbonate/acrylonitrile-butadiene-styrene blend by the ASTM E813 and hysteresis energy J integral methods: Effect of specimen thickness and side groove

The mechanical fracture and ductile-brittle transition (DBT) behavior, hysteresis phenomenon and the plastic zone size of polypropylene (PP) / ethylene-propylene-diene terpolymer (PP/EPDM) blends were investigated by varying EPDM content and notch radius under different temperatures. An increase in test temperature or rubber content in the PP/EPDM blend results in lower yield stress and Young's modulus. The ductile-brittle transition temperature (DBTT) of the notched impact strength decreases with the increase of the EPDM content. However, the DBTT is fairly independent of the notch radius. SEM morphologies of the fracture surfaces indicate that two separate modes, localized and mass shear yielding, work simultaneously in these blends. The plane-strain localized shear yielding dominates the brittle failure at lower temperatures, whereas the plane stress mass shear yielding dominates the ductile fracture at higher temperatures. The presence of EPDM rubber decreases the yield stress of the PP/EPDM blend due to the overlapping stress fields of adjacent particles, resulting in higher hysteresis energy. The relationships among the test temperature, hysteresis loss energy and the size of plastic zone are discussed in detail.

Ming-Luen Lu

Papers

Fracture-toughness of acrylonitrile-butadiene-styrene by j-integral methods

Fracture toughness of high‐impact polystyrene based on three j‐integral methods

Elastic-plastic fracture toughness of PC/ABS blend based on CTOD and J-integral methods

Fracture toughness of a polycarbonate/acrylonitrile-butadiene-styrene blend by the ASTM E813 and hysteresis energy J integral methods: Effect of specimen thickness and side groove

Fracture behavior of polypropylene/ ethylene- diene-terpolymer blends : Effect of temperatures, notch radius and rubber content