4D打印功能构件的热致变形模式分析与变形设计研究

Research on Behaviors of Functional Components Based on 4D Printing and Design of Temperature-driven Deformation

4D打印通过材料和结构的设计将非线性的控制逻辑打印在材料中,制备可以在温度、磁场、紫外线等激励下发生几何结构、功能、性能等可控转变的功能构件。以双层结构的功能构件为研究对象,通过对温度激励下功能构件基体相和增强相的热膨胀进行分析,研究了4D打印功能构件的热致变形机理,得到了基于形状记忆聚合物纤维排布的功能构件变形模式。在此基础上,分析了功能构件的3D打印工艺参数影响,建立了功能构件热致变形的近似解析模型。采用偏最小二乘法拟合了弯曲和螺旋变形的功能构件热致变形等效模型,通过4D打印的功能构件试件的变形特征与模型计算对比,验证了所拟合的等效模型的正确性。最后,设计并4D打印制备了自变形盒型功能构件和自组装螺旋连接功能构件,验证了功能构件形状、功能和特性的设计和可控编辑,对设计4D打印的功能构件具有指导意义。

4D printing is an intelligent additive manufacturing technology based on 3D printing.It is applied to fabricate functional components that perform controllable transformations of geometric structure,function and performance under external excitation such as temperature,magnetic field and ultraviolet ray.A bilayer functional component was employed and the thermal expansions of two layers are analysed.The thermal deformation mechanism of 4D printed functional components is investigated and the deformation patterns of functional components based on arrangement of shape memory polymer fibre are obtained.Then,effect of 3D printing process parameters on functional components is analysed,and an approximate analytical model of temperature-driven deformation of functional components is established.The equivalent temperature-driven deformation models of bending and helixing behaviors are fitted by partial least squares method.These models are verified by the comparison between the measured values and calculated values.Finally,a self-folding functional component and a self-assembling functional component are designed and fabricated by 4D printing.The programmability of functional components is verified and it is helpful to design the behaviors of functional components based on 4D printing.