Various sandwich structures have been developed as lightweight structures. They have excellent specific stiffness owing to their low density. However, owing to the existence of various failure modes, which are classified into core shear failure, tensile fracture of the face sheet, buckling of the face sheet, and delamination, it is difficult to deform sandwich sheets without any failure. A new forming strategy was proposed in this study. Buckling of the face sheet during drawing was suppressed by filling the encapsulated media in a 3D core between the face sheets to exploit its hydrostatic effect. This process is similar to the freeze-bend method, in which the pipe is filled with ice during bending to suppress wrinkles and flattening. Ice, wax, and low-melting alloys were used as the encapsulated media, and their formability and ease of removal were investigated. Further, a shear strength test was performed on the specimens that were cut out from the drawn products to evaluate failure during forming. Based on these experimental results, the characteristics required for the encapsulated media were summarized.

各种夹层结构已被开发为轻质结构。由于密度低，它们具有优异的比刚度。然而，由于存在多种失效模式，包括芯材剪切失效、面板拉伸断裂、面板屈曲和分层，因此很难使夹芯板变形而不发生任何失效。本研究提出了一种新的成形策略。通过将封装介质填充到面板之间的 3D 芯中以利用其静水效应，可以抑制拉伸过程中面板的弯曲。这个过程类似于冷冻弯曲方法，在弯曲过程中管子充满冰，以抑制皱纹和压扁。使用冰、蜡和低熔点合金作为封装介质，并研究了它们的成形性和易去除性。另外，对从拉拔制品切出的试验片进行剪切强度试验，评价成形时的破坏。根据这些实验结果，总结了封装介质所需的特性。