State-of-the-art tensile properties data generation for reinforced composites materials including tensile strength, tensile modulus and Poisson's ratio using align-pro, strain gages or extensometers performed at ambient, high or low temperatures with or without moisture conditioning.
ASTM D3039 tensile testing is used to measure the force required to break a polymer composite specimen and the extent to which the specimen stretches or elongates to that breaking point. Tensile tests produce a stress-strain diagram, which is used to determine tensile modulus. The data is often used to specify a material, to design parts to withstand application force and as a quality control check of materials. Since the physical properties of many materials can vary depending on ambient temperature, it is sometimes appropriate to test materials at temperatures that simulate the intended end use environment.
Test procedure:
Specimens are placed in the grips of a Universal Test Machine at a specified grip separation and pulled until failure. For ASTM D3039 the test speed can be determined by the material specification or time to failure (1 to 10 minutes). A typical test speed for standard test specimens is 2 mm/min (0.05 in/min). An extensometer or strain gauge is used to determine elongation and tensile modulus. Depending upon the reinforcement and type, testing in more than one orientation may be necessary.
State-of-the-art equipment including Align-pro for reduced bending.
Elevated or reduced temperature test procedure:
A thermal chamber is installed on a Universal Test Machine. The chamber is designed to allow the test mounts from the base and crosshead of the Universal Tester to pass through the top and bottom of the chamber. Standard test fixtures are installed inside the chamber, and testing is conducted inside the controlled thermal environment the same as it would be at ambient temperature. The chamber has internal electric heaters for elevated temperatures and uses external carbon dioxide gas or liquid nitrogen as a coolant for reduced temperatures.
Specimen size:
The most common specimen for ASTM D3039 is a constant rectangular cross section, 25 mm (1 in) wide and 250 mm (10 mm) long. Optional tabs can be bonded to the ends of the specimen to prevent gripping damage.
Data:
From tensile test results the following calculations can be made :
- Tensile strength (MPa or PSI)
- Tensile chord modulus of elasticity (MPA or PSI)
- Tensile strain (%)
- Poisson’s ratio (Upon Request)
- Transition Strain (%) (Upon Request)
Related Links
Tensile Testing for Plastics
Polymers and Plastics
