Compressive Properties/Compression Stress Value/Compression Stress-Strain Characteristics

ISO 3386, ASTM D3574-C and factory regulations

The compression stress value is the pressure resistance that a defined specimen under specified environmental conditions applies to a defined whole-surface compression.
Compression stress value of soft foam to ISO 3386
In this scenario, the deformation behavior of the specimen is relatively complex. Lateral movement of the cell structure with corresponding shearing occurs near the side cut surface, while the pure compression deformation is predominate in the center. For this reason it is not possible to effectively compare measured values that are determined from specimens of various dimensions using this test method.

Standards for This Test

The standard specimens have a quadratic cross-section with a lateral edge length of 5 or 100 mm. ASTM D3574 specifies an additional specimen with a round cross-section and a diameter of 57 mm.
Force travel curve compression properties, compression stress value ISO3386
Generally the test consists of three preload cycles, followed by a measuring cycle in which the characteristic values are determined. The initial height of the specimen is determined directly by the testing machine at the beginning of the first preload cycle. According to ASTM D3574, the height and travel-zero point is redetermined before the measuring cycle. Variations of this method are described in the various factory regulations.
Screen_compression stress

The methods used by Renault and PSA are exceptions. The test consists of a total of five test cycles, of which the first and the last are evaluated. To increase the accuracy of the travel measurement, this standard specifies the correction for machine deformation. These correction options are available with all ZwickRoell testing machines as a standard function.

The density measurement process can be integrated in the test sequence. Density is measured using a scale that is connected to the PC.



Compression test on soft polymer foams

ZwickRoell ProLine materials testing machine, components testing