Measuring the Stress & Strain of Origami Tubes.
Miura-ori folds made with colorful Fine Paper. (Photo: Hirata Masakazu, Hakuhodo Product's Incs. / Shown at the "Breathing of ORIGAMI Mihoncho Honten Exhibition, TAKEO Co., Ltd.
Stress & Strain Analysis of Origami Tubes
Measurement & Instrumentation (MIT Course #: 2.671)
Experimental Design & Testing, Data Analysis, Research Writing
Sept - Dec 2017
Instron, Vinyl Cutter, Vernier Software & Technology
Structural Origami shapes are increasingly being utilized in the field of engineering. For example, space satellites readily use origami-based patterns because it makes it easily fold-able (for compactness) and deploy-able.
In this study, Origami structures with a different number of tubes (2 tubes, 3 tubes, and 4 tubes) were tested with an Instron in order to measure the Young’s Modulus of each structure. It was found that the Young’s Modulus for a structure decreased when the number of tubes increased.
The origami tubes I designed were based on the Miura folding pattern. Miura folding is the method of folding a flat surface such that a sheet of paper folds into a smaller area. Miura folding’s name is derived from the man who created it, Koryo Miura. While researching at Tokyo University’s Institute of Space and Aeronautical Science department, Professor Miura came up with this folding method in order to package solar panels inside narrow rockets which could then be unfolded in space to operate. Miura folding loosely influenced the creation of this experiment’s origami configurations in that they both are collapsible and have pre-creased places that are in a vague grid shape.
Packing large objects into a smaller space is the main reason why Miura folding is widely used. It’s unique that in each folding and unfolding process, the folded/unfolded sheet of paper remains flat, only constrained by the thickness of the paper. The special parallelograms that are formed on the sheet allow the paper to fold and unfold quickly. Allowing paper to fold and unfold quickly allows technology to be used as soon as possible when it is deployed.
In order to evaluate the Young’s Modulus of different origami configurations, an experiment was conducted using an Instron on hand-made origami tubes structures.
The Origami tubes had three configurations: 2 tubes, 3 tubes, and 4 tubes. The Miura fold pattern was vinyl cut on many sheets of paper to keep consistency in area of the tubes. Each tube’s base was cut to be 0.02 m by 0.02 m. Then the two halves of the tube were combined and the base of the origami configurations were epoxied to foam core to provide a flat surface for. By attaching a string to the top and bottom of each configuration’s foam core board, it provided a “handle” for the Instron to hang on to and pull the configuration in tension. Also, the epoxy serves as a strong bond between the configurations to the “handles”; it ensures that the force the Instron exerts is evenly distributed across the configuration.
Data was collected by three trials for each origami configuration. First the two tube configuration was tested, then the three tube configuration, and then four tubes was tested last. Measurement was taken with an Instron. Instron was connected to a load cell which measured the force the Instron applied to the origami configuration. The load placed on origami configuration pulled it in tension. The trial ended when the origami configuration reached a strain of 60%.