Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 9 Fracture Testing

Similar presentations

Presentation on theme: "Chapter 9 Fracture Testing"— Presentation transcript:

1 Chapter 9 Fracture Testing

2 Charpy Impact Testing Impact Testing Impact Testing (a) Charpy impact
testing machine. (b) Charpy impact test specimen. (c) Izod impact test specimen.

3 Energy Absorbed vs. Temperature
Energy absorbed versus temperature for a steel in annealed and in quenched and tempered states. (Adapted with permission from J. C. Miguez Suarez and K. K. Chawla, Metalurgia-ABM, 34 (1978)‏ 825.)‏

4 Temperature Effect on Fracture Surface
Effect of temperature on the morphology of fracture surface of Charpy steel specimen. Test temperatures Ta < Tb < Tc < Td. (a) Fully brittle fracture. (b, c)‏ Mixed-mode fractures. (d) Fully ductile (fibrous) fracture.

5 Charpy Testing of Steel: DBTT
Results of Charpy tests for AISI 1018 steel (cold drawn).

6 Drop-Weight Test Specimen

7 Charpy V-notch Curve Charpy V-notch curve
for a pressure-vessel steel. Note that the NDT temperature determined by the drop-weight test corresponds to the high-tough region of the Charpy curve. Pneumatic pressurization; material: 21/4 Cr-1 Mo steel, yield stress 590 MPa. (After W. J. Langford, Can. Met. Quart., 19 (1980) 13.)‏

8 Oscilloscope Record (a) Typical oscilloscope
record of an instrumented Charpy impact test. (b) Schematic representation of (a).

9 Fracture Toughness Test Specimens
Typical ASTM standard plane-strain fracture toughness test specimens. (a) Compact tension. (b) Bending. (c)‏ Photograph of specimens of various sizes. Charpy and tensile specimens are also shown, for comparison purposes. (Courtesy of MPA, Stuttgart.)‏

10 Load Displacement Curves vs. Fracture Toughness Test
Schematic of typical load–displacement curves in a KIc test.

11 Plastic Zone at Crack Tip
Plastic zone at the x1 crack tip in a plate of finite thickness.

12 Displacement Measurement
Assembly for measuring displacement in a notched specimen.

13 Measuring Conditioned Value KQ


15 Variation of Kc with Specimen Thicckness
Variation in Kc with flaw size, specimen thickness, and specimen width.

16 Load P vs. Crack Opening Displacement: Different Responses

17 Plastic Hinge Mechanism
mechanism of deformation.

18 J-Integral Testing Method for determining JIc. (a) Load identical
specimens to different displacements. (b) Measure the average crack extension by heat tinting. (c) Calculate J for each specimen. (d) Plot J versus a to find JIc.

19 Flexure Test Normal stresses along a section of beam for linearly
elastic material.

20 Three-Point and Four-Point Bend (Flexure) Tests
TThree-Point Application of loads and bending moment diagrams for (a) three-point bending and (b)‏ four-point bending tests.

21 Miniaturized Specimen:Four-Point Bending
Shematic drawing of the miniaturized disk-bend test. (Adapted from H. Li, F. C. Chen, and A. J. Ardell, Met. Trans A, 22 (1991) 2061.)‏

22 Fracture Testing Methods for Ceramics
methods for brittle materials. (a)‏ Double-cantilever beam (DCB). (b)‏ Double torsion. (c) Notch flexure.

23 Chevron Notch Test Chevron notch test. (a) Schematic of the test
arrangement and the details of the notch plane. (b) The chevron tip length, a0, can be measured from optical micrographs of broken specimens. (c) Chevron short-rod specimen.

24 Hardness Indentation in Brittle Materials
Fractures produced by hardness indentations in (a) AsS3 glass (courtesy of B. R. Lawn and B. J. Hockey) and (b) Al203. Add equation

25 Plastic Deformation and Crack in Indentation of Brittle Material
Schematic representation of indentation generating a plastic deformation region and a semicircular crack.

26 Fracture Toughness: Comparison by Different test Methods
Comparison between conventional and indentation fracture toughness determinations for glasses and ceramics. (From G. R. Anstis, P. Chankitul, B. R. Lawn, and D. B. Marshall, J. Am. Cer. Soc., 64 (1981) 533.)‏

27 Adhesion of Thin Film to Substrate: Testing
Indentation tests for the determination of toughness of bond between substrate and thin film; (a) method used for ductile coating on brittle substrate (typical of electronic components); (b)‏ method used for brittle coatings on ductile substrate; (c) calculated normalized energy release rate as a function of normalized crack diameter. (Adapted from J. J. Vlassak, M. D. Drory, and W. D. Nix, J. Mater. Res., 12 (1997) 100.)‏

Download ppt "Chapter 9 Fracture Testing"

Similar presentations

Ads by Google