Unified parameter of in-plane and out-of-plane constraint effects and its correlation with brittle fracture toughness of steel

The brittle fracture constraint effect in two different weld thermal simulated microstructures of a 500 MPa steel is investigated through testing of bending specimens with different a/W ratios. It is found that on average the constraint effect is higher in the CGHAZ microstructure compared to the ICCGHAZ. The procedure for calibration of Weibull parameters proposed by Gao et al. [1] has been applied to the results. It is found that a lower m-value is calibrated for the ICCGHAZ microstructure due to the lower constraint effect observed. Three-parameter representations of the Weibull distribution better represent the distribution of the fracture toughness values compared to two-parameter representations.

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2 1/4% NICKEL STEEL

Alloy Digest ◽

10.31399/asm.ad.sa0378 ◽

1980 ◽

Vol 29 (11) ◽

Keyword(s):

Fracture Toughness ◽

Corrosion Resistance ◽

Brittle Fracture ◽

Physical Properties ◽

Heat Treating ◽

Pressure Vessels ◽

Nickel Steel ◽

Subzero Temperatures ◽

Steel Mills ◽

Resistance To Brittle Fracture

Abstract The 21/4% Nickel Steel possesses a combination of moderate strength and superior resistance to brittle fracture at subzero temperatures. It is one of the most economical materials for the construction of equipment to operate at temperatures as low as -90 F. It is intended primarily for welded pressure vessels. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-378. Producer or source: Alloy steel mills and foundries.

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Fracture toughness correction due to the in- and out-of-plane constraints

Theoretical and Applied Fracture Mechanics ◽

10.1016/j.tafmec.2020.102844 ◽

2020 ◽

pp. 102844

Author(s):

Andrzej Neimitz ◽

Sebastian Lipiec

Keyword(s):

Fracture Toughness ◽

Out Of Plane

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In-plane and out-of-plane constraint effects under pressurized thermal shocks

International Journal of Solids and Structures ◽

10.1016/j.ijsolstr.2013.12.021 ◽

2014 ◽

Vol 51 (6) ◽

pp. 1311-1321 ◽

Cited By ~ 29

Author(s):

Guian Qian ◽

V.F. Gonzalez-Albuixech ◽

Markus Niffenegger

Keyword(s):

Out Of Plane ◽

Constraint Effects ◽

Thermal Shocks

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Fracture assessment of polycarbonate parts produced by fused deposition modeling in the out-of-plane printing direction – effect of raster angle

Rapid Prototyping Journal ◽

10.1108/rpj-08-2020-0191 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Iman Sedighi ◽

Majid R. Ayatollahi ◽

Bahador Bahrami ◽

Marco A. Pérez-Martínez ◽

Andrés A. Garcia-Granada

Keyword(s):

Fracture Toughness ◽

Finite Element ◽

Fracture Behavior ◽

Fused Deposition Modeling ◽

Mode I ◽

Content Type ◽

Fused Deposition ◽

Out Of Plane ◽

Deposition Modeling ◽

Fracture Tests

Purpose The purpose of this paper is to study the Mode I fracture behavior of polycarbonate (PC) parts produced using fused deposition modeling (FDM). The focus of this study is on samples printed along the out-of-plane direction with different raster angles. Design/methodology/approach Tensile and Mode I fracture tests were conducted. Semi-circular bend specimens were used for the fracture tests, which were printed in four different raster patterns of (0/90), (15/−75) (30/−60) and (45/−45). Moreover, the finite element method (FEM) was used to determine the applicability of linear elastic fracture mechanics (LEFM) for the printed PC parts. The fracture toughness results, as well as the fracture path and the fracture surfaces, were studied to describe the fracture behavior of the samples. Findings Finite element results confirm that the use of LEFM is allowed for the tested PC samples. The fracture toughness results show that changing the direction of the printed rasters can have an effect of up to 50% on the fracture toughness of the printed parts, with the (+45/−45) and (0/90) orientations having the highest and lowest resistance to crack propagation, respectively. Moreover, except for the (0/90) orientation, the other samples have higher crack resistance compared to the bulk material. The fracture toughness of the tested PC depends more on the toughness of the printed sample, rather than its tensile strength. Originality/value The toughness and the energy absorption capability of the printed samples (with different raster patterns) were identified as the main properties affecting the fracture toughness of the AM PC parts. Because the fracture resistance of almost all the samples was higher than that of the base material, it is evident that by choosing the right raster patterns for 3D-printed parts, very high resistance to crack growth may be obtained. Also, using FEM and comparing the size of the plastic zones, it was concluded that, although the tensile curves show nonlinearity, LEFM is still applicable for the printed parts.

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