For procedures, see your mechanical laboratory manual.

Title: Tensile tests experiment


Aim

To carry out tensile tests determine the load-deformation and the stress-strain curves for a variety of materials e.g mild steel, brass, copper, etc

Theory

Tensile testing, also known as tension testing is a fundamental material science and engineering test in which a sample is subjected to a controlled tension until failure.

Tensile testing is a destructive test process that provides information about the tensile strength, yield strength, and ductility of the metallic material. It measures the force required to break a composite or plastic specimen and the extent to which the specimen stretches or elongates to that breaking point.

The basic idea of a tensile test is to place a sample of a material between two fixtures called "grips" which clamp the material. The material has known dimensions, like length and cross-sectional area. We then begin to apply weight to the material gripped at one end while the other end is fixed. We keep increasing the weight (often called the load or force) while at the same time measuring the change in length of the sample.

Applications

Aerospace Industry

Applications of tensile testing in the aerospace industry include:
1. Peel tests on airframe composites
2. Shear and tensile strength testing of fasteners e.g. bolts, nuts, and screws
3. Tensile & material strength testing of adhesive bonds, aircraft textiles and carpets, cables, hoses and tubing, gaskets and o-rings, seat belts, welded and crimped joints, wiring looms and harnesses

Automotive Industry

Applications of tensile testing in the automotive industry include:
1. Quality assessment through tensile testing of interior fittings including airbags, carpets, dashboards, electrical harness (incl. crimped terminals pull-off force), handles, laminated trim, mirrors, seats and seatbelts, and handbrake levers.
2. Quality assessment through tensile testing of exteriors fittings including bumper moldings and trims, door and window seals, emblems and number plates, mirrors and mud flaps

Beverage Industry

Applications of tensile testing in the beverage industry include:
1. Peel strength of induction-sealed foils and labels
2. Tensile force required to open 'ring-pulls' on bevcans
3. Testing cork extraction force

Construction Industry

Applications of tensile testing in the construction industry include:
1. Bond strength testing of adhesives, mastics, sealants, and bonds between brick and foam layers
2. Tensile and material strength testing of geotextiles and safety support netting

Electrical and Electronics Industry

Applications of tensile testing in the electrical and electronics industry include:
1. Connector withdrawal force
2. Pull-off forces of crimped, welded, or soldered electrical contacts
3. Component-to-PCB pull-off force
4. PCB material tensile strength

Medical Device Industry

Applications of tensile testing in the medical device industry include:
1. Hypodermic needle-to-hub retention force
2. Tensile strength and elongation at break of medical tubing, bandages, dressings, and tapes
Joint strength of IV connector fittings
Suture-to-needle crimp pull out test
3. Tensile strength of suture material and knotting
4. Joint strength and material elongation of respiratory masks
5. Elongation and tensile strength of examination gloves
6. Mechanical strength of orthopedic implant components

Packaging Industry

Applications of tensile testing in the packaging industry include:
1. Adhesive/peel testing of adhesive bonds, container seals, and labels
2. Force associated with opening snap-caps, pop-caps, and other push-pull closures
3. Elongation of plastic packaging materials

Paper and Board Industry

Applications of tensile testing in the paper and board industry include:
1. Openability of card and paper-based packaging
2. Folding characteristics of boxes and cartons
3. Force to separate multi-part documents
4. Durability of documents

Pharmaceuticals Industry

Application of tensile testing in the pharmaceuticals industry include:
1. Pull-off force of phial caps

Plastics, Rubber and Elastomers Industry

Applications of tensile testing in the plastics, rubber, and elastomers industry include:
1. Joint strength of interlocking plastic components
2. Assessment of material tensile properties
3. Adhesion/peel testing of plastic labels, ID, and credit cards

Safety, Health, Fitness and Leisure Industry

Applications of tensile testing in the safety, health, fitness, and leisure industry include:
1. Tensile testing of safety support netting
2. Ergonomic risk evaluations
3. Elastic properties of racquet strings

Textiles Industry

Applications of tensile testing in the textiles industry include:
1. 'Pull-off' characteristics of buttons, stitched-on decorations, press studs, poppers, zip fasteners, hook-and-loop fasteners
2. Strength testing of vulnerable seams

References

1. Tensile testing, sciencedirect.com
2. Tensile testing, wikipedia.org
3. Tensile Test Experiment, Michigan Tech www.mtu.edu
4. What is Tensile Testing? The Theory and Applications, Azom Materials www.azom.com