中文摘要：

决定为多孔、多相的 nanocrystalline 材料的时间无关的组成的建模并且在他们的机械行为上理解谷物尺寸和孔的效果，每个阶段被当作谷物内部和谷物边界的混合物，并且毛孔作为一个单个阶段被拿，然后， Budiansky 的前後一致的方法被用来计算幼仔的模量多孔，可能多相， nanocrystalline 材料，在对在文学的结果的好同意的预言。进一步，确定的方法被扩大与 secant-moduli 途径和 iso 紧张假设一起与小塑料变丑模仿多孔、可能的多相的 nanocrystalline 材料的组成的关系。在试验性的谷物尺寸和孔依赖者之间的比较用确定的模型的机械数据和相应预言证明它看起来能够在一个小塑料紧张范围为多孔、多相的 nanocrystalline 材料描述时间无关的机械行为。开发的模型的修正因素，优点和限制的进一步的讨论是在场的。

英文摘要：

To determine the time-independent constitutive modeling for porous and multi- phase nanocrystalline materials and understand the effects of grain size and porosity on their mechanical behavior, each phase was treated as a mixture of grain interior and grain bound- ary, and pores were taken as a single phase, then Budiansky＇s self-consistent method was used to calculate the Young＇s modulus of porous, possible multi-phase, nanocrystalline materials, the prediction being in good agreement with the results in the literature. Further, the established method is extended to simulate the constitutive relations of porous and possible multi-phase nanocrystalline materials with small plastic deformation in conjunction with the secant-moduli approach and iso-strain assumption. Comparisons between the experimental grain size and porosity dependent mechanical data and the corresponding predictions using the established model show that it appears to be capable of describing the time-independent mechanical behaviors for porous and multi-phase nanocrystalline materials in a small plastic strain range. Further discussion on the modification factor, the advantages and limitations of the model developed were present.