Deformation sequence of a constrained spatial buckled beam under edge thrust

• A clamped beam under edge thrust constrained inside a tube is investigated.
• Small-deformation theory is adopted.
• Two-point-contact deformation jumps to one-point-contact deformation suddenly.

In this paper we study the deformation evolution of a clamped-clamped beam under edge thrust constrained inside a straight tube. Small-deformation theory is adopted. As the edge thrust decreases gradually, the constrained rod deformation evolves from a point-line-point contact to three-point, two-point, one-point contact, and finally back to straight configuration. According to the small-deformation theory, the one-point-contact deformation is a planar one, while all others are three-dimensional in a shape close to a helix. It is found that the helical two-point-contact deformation “jumps” to planar one-point-contact deformation suddenly. It is argued that this peculiar jump phenomenon is due to the limitation of the small-deformation theory.