Wave propagation in slender beams is addressed in the framework of nonlocal continuum mechanics. The elastodynamic problem is formulated exploiting consistent methodologies of pure integral, mixture and nonlocal strain gradient elasticity. Relevant wave solutions are analytically provided, with peculiar attention to reflection and near field phenomena occurring in presence of boundaries. Notably, the solution field is got as superimposition of incident, reflected, primary near field and secondary near field waves. The latter contribution represents a further effect due to the size dependent mechanical behaviour. Limit responses for vanishing nonlocal parameter are analytically evaluated, consistently showing a zero amplitude of the secondary near field wave. Parametric analyses are carried out to show how length scale parameter, amplitude of incident wave and geometric and elastic properties of the beam affect the amplitudes of reflected, primary near field and secondary near field waves. The results obtained exploiting different nonlocal integral elasticity approaches are compared and discussed.

细长梁中的波传播在非局部连续介质力学的框架中得到解决。弹性动力学问题是利用纯积分、混合和非局部应变梯度弹性的一致方法来表述的。通过分析提供了相关的波解，特别关注边界存在时发生的反射和近场现象。值得注意的是，解场是由入射波、反射波、初级近场波和次级近场波的叠加得到的。后一种贡献代表了由于尺寸相关的机械行为而产生的进一步影响。对消失的非局部参数的极限响应进行了分析评估，一致地显示了二次近场波的零振幅。进行参数分析以显示长度尺度参数、入射波振幅以及光束的几何和弹性特性如何影响反射波、初级近场波和次级近场波的振幅。比较和讨论了利用不同非局部积分弹性方法获得的结果。