细观几何结构对复合材料初始屈服面的影响

采用宏—细观统一的弹塑性本构模型分析了多轴载荷作用下不同纤维形状、不同纤维排列方式对金属基复合材料初始屈服面的影响。研究表明:在纵向正应力作用下,圆截面纤维复合材料的初始屈服应力基本上与方形截面纤维复合材料的初始屈服应力相等;不同纤维排列方式的复合材料初始屈服应力基本上相同。当存在横向应力或纵横剪切应力时,圆截面纤维复合材料初始屈服面在方形截面纤维复合材料初始屈服面之内;六角形排列时最容易屈服,而方形对角排列屈服应力最高。 

Influence of Micro-Structural Geometry on Composite Initial Yielding Surfaces

The unified macro and micro mechanics constitutive model was used to investigate the influence of micro-structural geometry,such as fiber shape and fiber packing array,on the composite initial yielding surfaces under multi-axial loading.Under longitudinal stress,composites reinforced by fibers with square cross section have the same yielding stress as the ones reinforced by fibers with cyclic cross section.Fiber packing array has no effect on the yielding stress.In the presence of transverse or shear stresses, the composite initial yielding surface with square cross section fibers is inside of the one of composite with square cross section fibers.Composite with hexagon fiber array has the lowest yielding stress;however,composite with square-diagonal fiber array has the highest.