ASTM C1259 Dynamic Young’s Modulus, Shear Modulus, and Poisson’s Ratio for Advanced Ceramics

Scope:

The elastic properties of advanced ceramics such as dynamic young’s modulus, shear modulus, and Poisson’s ratio are determined using the ASTM C1259 test method, which involves impulse excitation of vibration. For quality control and acceptance of test specimens of both regular and complex shapes, this method can be employed to detect resonance frequencies alone. This test method is for determining the dynamic moduli of elasticity of slender bars (rectangular cross-section) and rods (cylindrical) at room temperature, but it may also be done at cryogenic and high temperatures with the right equipment.

Procedure:

ASTM C1259 test method uses a unique elastic strike with an impulse tool to measure the fundamental resonant frequency of test specimens of proper shape. The ensuing mechanical vibrations of the specimen are sensed by a transducer, which converts them into electric impulses. To generate and measure certain modes of transient vibrations, specimen supports,  impulse sites, and signal pick-up points are chosen. The analyzer isolates and measures the fundamental resonant frequency which gives a numerical reading that is proportional to either the frequency or period of the vibration. The Dynamic Young’s modulus, dynamic shear modulus, and Poisson’s ratio are calculated.

Specimen size:

The ASTM C1259 test method uses test specimens in the bar, rod, and disc geometries. 

Specimen mass must be within 0.1% or 10 mg, specimen length must be within 0.1%, and specimen thickness and width must be within 0.1% or 0.01 mm. 

Data:

In ASTM C1259, Dynamic Young’s Modulus, Shear Modulus & Poisson’s Ratio of ceramic are reported in the SI unit and are considered as standard.

Modification of this test method for use in quality control is also possible.

Conclusion:

The ASTM C1259 test method uses impulse excitation of vibration to determine the elastic properties of advanced ceramics such as dynamic young’s modulus, shear modulus, and Poisson’s ratio.