TENSILE TEST

GUIDED BY:Mr. KUNAL SAURABH(Assistant Professor)(Mechanical Department)

PRESENTED BY:RISHI KUMAR VERMARoll no:12090326(5.4.2)

DEPARTMENT OF MECHANICAL ENGINEERINGIEC COLLEGE OF ENGINEERING

& TECHNOLOGY

Tensile Testing

• Uses an utm to apply measured force to an test specimen. The amount of extension can be measured and graphed.

• Variables such as strain, stress, elasticity, tensile strength, ductility and shear strength can be gauged.

• Test specimens can be round or flat.

Why are metals tested ?

• Ensure quality • Test properties• Prevent failure in use• Make informed choices in using material

The following MATERIAL PROPERTIES Can Be Determined

By TENSILE TESTING:

• STRENGTH• DUCTILITY• ELASTICITY• STIFFNESS• . MALLEABILTY• . MODULUS of TOUGHNESS• . MODULUS of RESILIENCE

A machine which applies a tensile force (a force applied in opposite directions) to the specimen, and then measures that force and also the elongation:

This machine usually uses a hydraulic cylinder to create the force. The applied force is determined by system pressure, which can be accurately measured.

The Tensile Tester

HYDRAULIC UNIVERSAL TESTING MACHINE

A universal testing machine (UTM), also known as a universal tester, materials testing machine or materials test frame, is used to test the tensile stress and compressive strength of materials . It is named after the fact that it can perform many standard tensile and compression tests on materials, components, and structures.

Load- Extension graph for Ductile Material

Comparative Stress-Strain

Stress strain diagram for brittle materials

• Brittle material : The rupture occurs along a surface perpendicular to the loading plane. For ex: glass, stone, normal concrete, aluminum.

Tensile Strength

Tensile strength = Maximum LoadCross section area

Maximum load is the highest point on the graph.

Often called Ultimate Tensile Strength (UTS)

Modulus of ElasticityModulus of Elasticity -A measure of a materials ability to regain its original dimensions after the removal of a load or force. The modulus is the slope of the straight line portion of the stress-strain diagram up to the proportional limit.

Calculation

E = (F1 -F2)Lo / (1 - 2)AGraph

Strain () in/in

Stre

ss (S

) psi Proportional / Elastic Limit

Slope

Breaking/Rupture StressBreaking/Rupture Stress - The maximum amount of stress that can be applied before rupture occurs. The material fractures in the necking region where the material reduces in diameter as the material elongates.

Graph

Strain () in/in

Stre

ss (S

) psi

Rupture Point

Necking Region

Strain () in/in

Stre

ss (S

) psi

Elastic Region

Modulus of ResilienceModulus of Resilience -A measure of a materials ability to absorb energy up to the elastic limit. This modulus is represented by the area under the stress versus strain curve from zero force to the elastic limit.

Calculation

Ur = 1/2 (yp)( yp)

Graph

Elastic Limit

Modulus of ToughnessModulus of Toughness -A measure of a materials ability to plastically deform without fracturing. Work is performed by the material absorbing energy by the blow or deformation. This measurement is equal to the area under the stress versus strain curve from its origin through the rupture point.

Graph

Strain () in/in

Stre

ss (S

) psi

Plastic Region

Calculation:

Ut = 1/3(Br) (yp + 2ult)

Calculation Page

Total Strain/ Deformation -The total amount of elongation of a sample to rupture normalized(divided by) by the initial length.Calculation: total = total/Lo

Ductility:The ability of a material to be deformed plastically without rupture.Calculation: % Elongation = total(100)

Calculations: % Reduction in area = Aoriginal - A final / A original (100)

APPLICATION

• Aerospace Industry• Shear and tensile strength testing of fasteners

e.g. Bolts, nuts and screws

• Textiles Industry• 'Pull-off' characteristics of buttons, stitched-on

decorations, press studs, zip fasteners, hook-and-loop fasteners

Benefits of Tensile Testing

• Benefits of Tensile Testing• The data produced in a tensile test can be

used in many ways including:• To determine batch quality• To determine consistency in manufacture• To aid in the design process• To reduce material costs and achieve lean

manufacturing goals