Abstract: A support element assembly includes at least two types of standard blocks. The standard blocks are connected to each other and selected from the group consisting of a first standard block having a first elastic constant and a first height, a second standard block having a second elastic constant and the first height, a third standard block having the first elastic constant and a second height, and a fourth standard block having the second elastic constant and the second height. The standard blocks are manufactured by 3D printing and have identical lattices, and each standard block has a jointing structure.

Abstract: The present disclosure provides a 3D printing method including: a resin providing step of providing a dual cure resin; a light curing step of irradiating the dual cure resin by an ultraviolet light to perform 3D printing so as to form an intermediate body having a predetermined lattice shape; a stretching step of applying a stress on the intermediate body in a stretching direction according to a stretching ratio of a predetermined size to stretch and form a stretched body; and a thermal curing step of heating the stretched body to perform thermal curing and shaping so as to form a 3D printing formed body. When the light curing step is performed, a size in a non-stretching direction of the intermediate body is correspondingly pre-compensated based on the stretching ratio. The present disclosure further provides a 3D printing formed body.

Abstract: A warning sign structure includes an activating mechanism and a stretching-retracting mechanism movably joined to the activating mechanism. The stretching-retracting mechanism includes a retractable unit connected to the activating mechanism and a light emitting unit movably disposed on a top of the retractable unit. When the vehicle breaks down, the activating mechanism drives a stretching-retracting mechanism to stretch its retractable unit to an appropriate height manually or automatically and turns on a light emitting unit. The light emitting unit emits light in a high position to warn the rear-coming vehicles. The driver can also detach the stretching-retracting mechanism and use the stretching-retracting mechanism as a hand-held warning sign or a traffic baton.