Сравнение динамических методов при определении упругих характеристик разных материалов

Abstract

В работе приведены результаты расчётов, а так же экспериментального определения импульсным и резонансным методами характеристик упругости различных материалов, как широко используемых, так и обладающих специальными свойствами. Отмечено, что разница между получаемыми по этим методам величинами модуля упругости изменяется в зависимости от свойств материала и может достигать 15 %. Для уменьшения расхождений рекомендуется адаптация метода измерений к исследуемому материалу.The paper gives calculation results and experimental evaluation of elastic characteristics for different materials using pulse and resonant methods. Widely used materials and materials of specific properties have been selected for investigations. It has been established that the difference between the values of modulus of elasticity obtained by the methods changes depending on the material properties and can amount to 15 %. As the measurement method must not influence the objective values of material elastic properties, one should search for the ways of improving these methods. One of such ways may be related to adapting the measurement method to the material under investigation. The increase in discrepancy between the values of modulus of elasticity evaluated by the pulse and resonant methods is conditioned by increasing Poisson coefficient and/or heterogeneity in the material. The latter results in unequal conditions for interaction between an elastic wave and material structural elements for different methods. The dissimilarity may be associated with different mechanisms, for example, the stress distribution inside the material or higher attenuation on the frequencies of the pulse method as a result of elastic wave scattering and absorption at the structural elements in the material.