Notes

Tensile test:
Tensile strength can be defined as the maximum stress that a material can bear before breaking when it is allowed to be stretched or pulled.
Tensile properties are evaluated by placing a test specimen between two clamps in a tensile or universal tester, which is a type of mechanical test equipment. The clamps are pulled apart using hydraulics or mechanical (servo screw drive) to apply tension until the sample breaks. The force applied is measured as well as the elongation (deformation or strain) induced in the sample. Since the cross-section of the polymer sample is known, a plot of stress versus strain can be generated. Tensile properties such as break tensile strength, tensile modulus and percent elongation at break can be determined.
Yield strength (A) - The point at which the material transforms from elastic to plastic is known as the yield point. The magnitude of the stress at which the transition from elastic to plastic occurs is known as the yield strength.
Ultimate strength (B) - The maximum stress a material can withstand
Breaking strength (C) - The stress coordinate on the stress-strain curve at the point of rupture
σ (stress) = F/A ε (strain) = ΔL/L0; ΔL = L-L0
Sample: ASTM D638-01 , Machine: Instron (system Id3369J8567) , Speed: 5mm/min

THREE POINT FLEXURE TEST:
Flexural strength is the ability of the material to withstand bending forces applied perpendicular to its longitudinal axis.
When a specimen is bent, it experiences a range of stresses across its depth. At the edge of the concave face of the specimen (point A), the stress will be at its maximum compressive value. At the convex face of the specimen (point B), the stress will be at its maximum tensile value. Most materials fail under tensile stress before they fail under compressive stress, so the maximum tensile stress value that can be sustained before the specimen fails is its flexural strength.
Sample: ASTM D790-00 Machine: Instron (system Id3369J8567) Cross head Speed:1mm/min


The Shore durometer is a device for measuring the hardness of a material, typically of polymers, elastomers, and rubbers.
The A scale is for softer ones, while the D scale is for harder ones. Durometer is measured by the depth of an indentation into the material under a standardized force. Softer material will allow a deeper indentation, while harder materials will allow the opposite.