Lab Manual | To perform the shear test on UTM

AIM :- To perform the shear test on UTM.

APPARATUS USED :- A UTM, Specimen, shearing attachment, vernier caliper etc.

THEORY :- A type of force which causes or tends to cause two contiguous parts of the body to slide relative to each other in a direction parallel to their plane of contact is called the shear force. The stress required to produce fracture in the plane of cross-section, acted on by the shear force is called shear strength.

PROCEDURE :-

The method for determining the shear strength consists of subjecting a suitable length of steel specimen in full cross-section to double shear, using a suitable test rig, in a testing m/c under a compressive load or tensile pull and recording the maximum load ‘F’ to fracture. OBSERVATION :-

· Applied compressive force (F) =——– kgf.

· Diameter of specimen =——— mm.

CALCULATION :-

The shear strength shall be calculated from the following formulae : τ_s = (F/2) / (πd²/4) = 2F / πd²

where ‘d’ is the actual diameter of the specimen

PRECAUTIONS :-

· The specimen should be all place equal dia.

· Measure the diameter of specimen carefully.

· The specimen should be properly grip between the test rig.

· Take reading more carefully.

· After shearing specimen stop to m/c.

CONCLUSION :-

VIVA-QUESTIONS :-

· Does the shear failure in wood occur along the 45° shear plane ?

· What is buldging? Why does it occur?

· What is single & double shear ?

· What is find in shear test?

· What is unit of shear strength ?