textile composites testing detailed discussion in advanced technologies

1. TESTING OF MECHANICAL
PROPERTIES OF TEXTILE
COMPOSITES
PRESENTED BY: 21-ME TE-04

2. OUTLINE:
 INTRODUCTION
 BRINELL HARDNESS TESTING
 TENSILE STRENGTH TESTING
 COMPRESSIVE STRENGTH TESTING
 FRACTURE TOUGHNESS TESTING
 FATIGUE TESTING
 REFERENCES

3. INTRODUCTION:
 Nowadays, composites replacing heavy materials so the demand of buyers from
composites have been increased as light in weight, have good strength,
drapability, cracking free, long life etc
 All these are considered in mechanical properties for this reason, testing of
mechanical properties are much needed to examine how much load these
composites can bear and how much requirement results are they achieving.
 Study of application of forces
 To check the performance of the material during loading

4. TESTING:
Brinell hardness testing
Tensile testing
Compression testing
Fracture toughness test
Fatigue testing

5. BRINELL HARDNESS TESTING
 Brinell hardness: the hardness of a metal or alloy measured by hydraulically pressing a
hard ball under a standard load into the specimen(1)
 Forcing of a hard steel with specified diameter under a specified load into the surface of
the material
 The Brinell hardness number shows the specified load of hard steel
 Brinell hardness test was conducted on the specimen using a standard Brinell hardness
tester.
 Experiment on glass fiber:
 A load of 300 kg was applied on the specimen for 30 sec using 5 mm diameter hard
metal ball indenter and the indentation diameter was measured using a microscope
containing an ocular, usually graduate in tenths of a millimeter, permitting estimates to
the nearest 0.05 mm. The surfaces of the specimen should be smooth and free of oil and
dirt. The hardness was measured at three different locations of the specimen and the
average value was calculated. (2)

6. Test Method Illustration
D = Ball diameter
d = impression diameter
F = load
HB = Brinell result
(3)

7. TENSILE STRENGTH TESTING
 ASTM D3039 / D3039M-17, Standard Test Method for Tensile Properties of
Polymer Matrix Composite Materials (4)
 Force required to break a polymer composite specimen
 Stress-strain diagram which used to determine tensile modulus
 Universal tester machine used to pulled a specimen upto its breaking point
 Specimen size, machine speed, time all are standardized according to
ASTM D-3039

8. UNIVERSAL TESTING MACHINE

9. COMPRESSIVE STRENGTH TESTING
 ASTM D6641 Standard Test Method for compressive Properties of Polymer Matrix
Composite Materials (5)
 This test method determines compressive properties by using combined loading
compression (CLC)
 Test fixture is designed to provide combined loading to a unsupported specimen
TESTING PROCEDURE:
 The test specimen is inserted into two halves of the test fixture and specimen ends are
flush with the top and bottom of the test fixture, and bolts are fixed with specimen to
capture specified torque
 The fixture is set in universal testing , and a strain measuring device is also attached
between the halves.

10. COMPRESSIVE STRENGTH TESTING

11. FRACTURE TOUGHNESS TESTING
 Fracture toughness by using a mixed-mode bending to understand
susceptibility to delamination by observing the interlaminar fracture
toughness.[6]
 Mixed mode is ASTM standard which shows mode :I and mode :II.
 Mode:1 in crack opening and mode:2 is sliding mode with delamination
occurs by sliding faces over each other.

12. FRACTURE
TOUGHNESS
TESTING
PROCEDURE:
Insert specimen in mixed mode
Universal machine is used to
apply force to the specimen
Record force and displacement

13. FATIQUE TESTING:
 Cracks in a material by cyclic loading, once it intiated it grows small amount after each
loading.
 Fatigue cause huge damage throughout specimen volume, and its general degradation of
the material instead of single crack mark
 Fatigue testing is a specialised form of mechanical testing that is performed by applying
cyclic loading to a structure.
 Applying constant stress until it loss strength.
CAUSE OF FATIGUE:
1. Matrix cracking
2. Delamination
3. Fiber breakage

14. FATIGUE TESTING:
 When fatigue testing takes place, materials or objects are placed into a
testing machine and various loads are applied
 The test can be carried out for a specified length of time, in order to
observe the effects after that length of time.
 The normal reason for carrying out these tests is to determine the
lifespan for a material that has to withstand this type of cyclic loading
(7)

15. REFRENCES:
[1] Merriam-webster 1828.
[2] wazery, elamy “mechanical properties of glass fibers reinforced polyester
composite” 2017.
[3] newage hardening testing “ ametek sensors, test and calibration” manufacturer
[4] ASTM official website
[5] ASTM official website
[6] A.P. Mouritza,*, C. Bainib, I. Herszbergc “Mode I interlaminar fracture toughness
properties of advanced textilefibreglass composites” 1998
[7] baumann, hausmann “Compression Fatigue Testing Setups for Composites—A
Review” 2021.