双剪切试样用于短纤维金属基复合材料的蠕变响应研究

利用纵向各向异性有限元模型对双剪切试样的蠕变响应进行了有限元分析，其目的是为了研究双剪切试样用于短纤维金属基复合材料（MMC）蠕变响应研究的可行性。双剪切试样的蠕变响应与试样的取向和材料的各向异性有关。详细的应力分析表明，双剪切试样在受剪切区域能提供稳定的应力状态，该应力接近于施加应力的平均值，并与试样的取向及材料的各向异性不相关，即双剪切试样可以为MMC提供一简单的复杂应力，提出了用双剪切实验结果来推得MMC蠕变性能和各向异性参数的方法，以便可以用双剪切实验来确定那些很难用拉伸和单向压缩实验确定的各向异性材料的参数。

APPLICATION OF THE DOUBLE SHEAR CREEP SPECIMENS ON THE FIBER-REINFORCED METAL MATRIX COMPOSITES

Double shear creep specimens were investigated by the transverse anisotropic finite element method, in order to study the multiaxial creep behavior of short fiber-reinforced metal matrix composites (MMCs). The creep behavior was dependent on orientations of the specimens and the transverse anisotropic parameters. The detailed evolution of the stress and strain in the double shear creep specimens shows that there is a steady stress state in the shear zone. The shear stress is near to the applied average shear stress, and independent of orientations of the specimens and the transverse anisotropicic parameters. The double shear specimen can provide a simple multiaxial stress state for MMCs. A procedure has been presented to evolve the parameters for the transversely anisotropic MMC materials, so that the double shear specimens can tested the transversely anisotropic material properties, some of which are difficult to get by the usual tensile specimens.