To determined Shear strength of Steel

To determined Shear strength of Steel

AIM: โ€“To determined Shear strength of Steel.

OBJECTIVE: โ€“ To conduct shear test on specimens under single shear and doubleย shear

APPARATUS: โ€“ Universal testing machine, Shear test attachment, Specimens

THEORY: โ€“ Place the shear test attachment on the lower table, thisย attachment consists of cutter. The specimen is inserted in shear test attachment &ย lift the lower table so that the zero is adjusted, then apply the load such that theย specimen breaks in two or three pieces. If the specimen breaks in two pieces thenย it will be in single shear & if it breaks in three pieces then it will be in doubleย shear.


Schematic universal testing machine
ย Schematic universalย testingย machine

PROCEDURE:-

1. Insert the specimen in position and grip one end of the attachment inย the upper portion and one end in the lower portion.

2. Switch on the main switch of universal testing machine.

3. The drag indicator in contact with the main indicator.

4. Select the suitable range of loads and space the corresponding weightย in the pendulum and balance it if necessary with the help of smallย balancing weights.

5. Operate (push) buttons for driving the motor to drive the pump.

6. Gradually move the head control level in left-hand direction till theย specimen shears.

7. Down the load at which the specimen shears.

8. Stop the machine and remove the specimen

OBESERVATIONS:-

Diameter of the Rod, D = โ€ฆ.. mm

Cross-section area of the Rod (in single shear) =ฯ€/4x d2 =โ€ฆ.. mm2

Cross-section area of the Rod (in double shear) =ย 

2x ฯ€/4x d2 =โ€ฆ.. mm2

Load taken by the Specimen at the time of failure, W =โ€ฆโ€ฆN



RESULT:-

The Shear strength of mild steel specimen is found

i) In single shear = โ€ฆ.. N /mm2

ii) In double shear = โ€ฆ.. N /mm2

PRECAUTIONS:-

1. The measuring range should not be changed at any stage during the test.

2. The inner diameter of the hole in the shear stress attachment should beย slightly greater than that of the specimen.

3. Measure the diameter of the specimen accurately.

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