单向EMC层合板折叠变形时纤维微屈曲解

Francis等对单向形状记忆聚合物复合材料（EMC）层合板在热激活温度下的折叠变形过程建立了理论分析模型，研究结果表明：在板的整个弯曲过程都存在半波长，且其值恒定不变．实际上，小曲率条件下纤维的微屈曲还没有发生，半波长根本不存在．本文指出其研究中的不足并加以完善．结果表明：纤维微屈曲半波长与板的弯曲曲率之间的关系曲线可分为两个阶段，在小曲率阶段，因超出模型的适用范围被视为无效曲线；在大于小曲率的阶段，随着曲率的增加，半波长趋于稳定，同时该曲线能初步识别出模型的适用与非适用曲率范围．事实表明所提出的改进结果更加符合FMr屋全柏酌弯曲空际

A solution of fiber microbuckling for packaged unidirectional EMC laminates

Francis and others have presented a theoretical model to study the deformation of Elastic Memory Composite （EMC） laminates under bending at a temperature above the polymer＇s glass transition temperature, and the results show that the half wavelength always exists and is constant in the whole bending process. In fact, fiber microbuckling does not occur and the half wavelength does not exist at all at low curvature stage. Our study results show that the relationship curve between the half wavelength and curvature of the plate can be divided into two stages. The curve is regarded as ineffec- tiveness at low curvature stage because of beyond the applicable range of model. With the increasing of curvature, the half wavelength fundamentally keeps constant at greater curvature stage. At the same time, the applicable and inapplicable curvature range of the model can be distinguished through the curve. It is apparent that the improved results are more suitable for the actual deformation of EMC laminates under bending.