岩土类材料的动弹性模量机理

MECHANISM OF DYNAMIC ELASTIC MODULUS OF GEOTECHNICAL MATERIALS

本文从两个方面考虑岩土类材料(包括岩石和砼材料)动弹模机理:一是从连续力学的粘弹性材料模型——线性A型出发,分别讨论在不同恒应变率、正弦波激励和突加载三种不同加载方式下所表现出的动态弹性模量;二是从非线弹性(不包括粘性)材料模型出发,讨论非线弹性材料悬梁作轴向振动(前面加集中质量块)时,自振频率随振幅而变化。结果表明:振幅越小,则自振频率越大,从而表现的动弹模越大,这是影响材料动弹模实验结果的重要原因之一。文中还讨论了理想线弹性梁各阶振型动弹模意义。

The mechanism of dynamic elastic modulus (DEM) of geotechnical materials, including rock and concrete, is probed in two repects: firstly, by use of the viscoelastic material model——linear type A, the DEM are probed in three loading ways respectively, which are constant strain rate loading, sine wave loading and sudden loading and secondly, by use of non-linear clastic materials models, the changes in axial natural frequencies of a beam, with a concentrated mass block attached, are probed when oscillation amplitudes are changed. It is shown that the smaller the amplitude, the bigger the natural frequencies, so the bigger the DEM is. That shows that non-linearity is one of the causes of change of DEM. Besides, the implications of the different order DEM are discussed.