ASTM D1822 Standard Test Method for Tensile-Impact Energy to Break Plastics and Electrical Insulating Materials

Get Certified ASTM D1822 Testing for Reliable Tensile-Impact Energy

During service, plastic and electrical insulating materials can be subjected to sudden tensile forces. Therefore, tensile-impact testing assesses how much energy a material absorbs before breaking under a controlled impact shock. ASTM D1822 offers a uniform method for measuring tensile-impact energy by pendulum. Results can be used for material comparison, product development, quality control, and the assessment of materials with varying flexibility.

• Measures the amount of energy needed to fracture specimens under tension and impact.
• Assesses plastics and electrical insulating materials.
• Subjects to shock loading in tension.
• Operates a calibrated pendulum tension/impact machine.
• Allows specimen geometries Type S and Type L.
• Aids in comparing and describing materials.
• Gives answers in SI units as the system of units.

What are the Uses of ASTM D1822 Testing?

ASTM D1822 testing helps engineers and technicians assess the energy needed to fracture a material under tension and impact loading. The impact of the results is that material behavior under sudden tensile forces can be compared. The ASTM D1822 standard-

• Determines tensile-impact energy.
• Helps to compare plastic materials.
• Determines fracture characteristics under impact loading.
• Assists in the development and quality control of materials.
• Assists in testing thin or flexible materials.
• Provides information about fracture energy.
• Helps select materials for sudden-loading applications.

Which materials can be tested under ASTM D1822?

ASTM D1822 is applicable to those plastics and electrical insulating materials which can be readily fabricated into standard tension-impact specimens. This method can also be used for rigid materials and specimens that are too flexible or thin for other impact methods. The standard allows Type S (short) and Type L (long) specimens. Type S specimens will have less extension and will offer more repeatability, whereas Type L specimens will have more extension and may offer more differentiation between materials.

Why is ASTM D1822 Important?

ASTM D1822 is a standardized test for determining the energy required to fracture a specimen by applying a tensile impact load. This information helps engineers compare how materials behave under sudden tensile forces. The test is valuable, as the tensile-impact energy is a measure of the material’s resistance to fracture under rapid loading. But if the result is to be correlated with another impact test or a particular test there, there must be supporting experimental evidence.

ASTM D1822 Testing Process and Data Collection

Technicians prepare representative specimens and determine the proper Type S or Type L geometry. Before testing, operators check the specimen dimensions and adjust the machine. Next, operators place the specimen between the pendulum and crosshead. One swing of the pendulum results in tensile shock loading, which fractures the specimen. Lastly, engineers calculate the energy required for fracture. The energy can be normalized to the minimum cross-sectional area and reported in units of kJ/m² or ft·lbf/in². Energy can also be reported in J or ft·lbf. Specimen type, thickness, tab width, method of preparation, test conditions, pendulum capacity, average result, standard deviation, and number of specimens tested.

Common Challenges and Troubleshooting

ASTM D1822 results are accurate when specimens are prepared consistently, geometry is correct, the machine is properly calibrated, and the test is configured properly. Differences in specimen preparation, thickness, and geometry may affect measured tensile-impact energy. Certain materials may have a variety of fracture modes and may yield more scatter in the data. Technicians should examine fractured specimens if the failure behavior cannot be adequately interpreted. Also consider crosshead bounce during fracture.

• The laboratory reports tensile-impact energy as normalized energy in kJ/m² or ft·lbf/in² and may also report total impact energy in J or ft·lbf, as applicable.
• The technician records the specimen type, as Type S and Type L specimens may produce different results because of their different extension characteristics.
• The analyst evaluates the measured impact energy while considering specimen dimensions, preparation, material characteristics, and fracture mode.
• The laboratory compares results obtained under equivalent machine and test conditions because results from different machine sizes should not automatically be considered equivalent.
• When comparing impact performance, the engineer interprets tensile-impact energy in relation to the material, specimen type, fracture behavior, and specified test conditions.

Link to ASTM D1822