The geometrical dog-bone and rectangular bar test specimen model were.
ASTM D638 PDF SOFTWARE
The results of this work are a useful tool to enhance confidence in the tensile mechanical properties of ASTM D638 Types II and IV geometries as statistically similar to those of ASTM D3039 samples, impacting engineering designs with traditional and emerging manufacturing methods. (CAD) software to ASTM D638-14 and ASTM D790-10 for tensile and bending test. A Finite Element study based on the empirical model shows how the proposed approach can be adopted for design purposes. The mechanical properties test results for the molded HDPE samples are validated using a Monte Carlo simulation to estimate uncertainties for the probability distribution of maximum stress at the yield point. HDPE is a thermoplastic polymer that is recyclable, can be 3D-printed, and has a wide range of engineering applications, from bottles to pipes to radiation protection shielding. This parametric study examines the scaling effects present in uniaxial tensile test specimens of molded high-density polyethylene (HDPE), with geometries ranging from Types I to IV of ASTM D638 to ASTM D3039. While the ASTM standards (ASTM D638 and ASTM D695) do not define the exact strain levels used to calculate the linear modulus or the specified offset. However, designs of large engineering structures may rely on mechanical properties based on ASTM D3039 for fiber-reinforced polymer composites. Specimen size: The most common specimen for ASTM D-638 is a Type I tensile bar.Test specimens following ASTM D638 standards are frequently used to measure the tensile properties of reinforced and unreinforced polymers machined with traditional machining and emerging manufacturing methods (additive manufacturing/3D printing). The size of the chamber places a limitation on the maximum elongation that can be reached, and extensometers are generally limited to no more than 200° C. The chamber has internal electric heaters for elevated temperatures and uses external carbon dioxide gas as a coolant for reduced temperatures. The target time from start of test to break should be from 30 seconds to 5 minutes. Speed depends on specimen shape and can range from 0.05 20 inches per minute. 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. Begin the test by separating the tensile grips at a constant rate of speed. 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 Method for Tensile Properties of Plastics. An extensometer is used to determine elongation and tensile modulus.Įlevated or Reduced temperature test procedure:Ī thermal chamber is installed on the universal test machine. For ASTM D 638 the test speed is determined by the material specification. Specimens are placed in the grips of the universal tester at a specified grip separation and pulled until failure. It is conducted on a universal testing machine (also called a tensile testing machine) at tensile rates ranging from 1 to 500 mm/min until the specimen fails (yields or breaks). Tensile tests measure the force required to break a plastic sample specimen and the extent to which the specimen stretches or elongates to that breaking point. ASTM D638 is performed by applying a tensile force to a sample specimen and measuring various properties of the specimen under stress. Intertek laboratories provide ASTM D-638 Plastics Tensile Testing data generation services including tensile strength, tensile modulus and elongation.
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