With the exploitation of offshore oil and gas gradually moving to deep water, higher temperature differences and pressure differences are applied to the pipeline system, making the global buckling of the pipeline more serious. For unburied deep-water pipelines, the lateral buckling is the major buckling form. The initial imperfections widely exist in the pipeline system due to manufacture defec...

The method of fracturing of oil gas reservoir is considered as an instrumental one for maximizing the yield. Multiple loads in a well fracturing operation may compel tubing string to yield, break and/buckle in a permanent spiral, leading to severe financial deficit. Mathematical models for mechanical analysis of fracturing string in whole fracturing operation are developed on the basis of opera...

Filopodia are long, fingerlike membrane tubes supported by cytoskeletal filaments. Their shape is determined by the stiffness of the actin filament bundles found inside them and by the interplay between the surface tension and bending rigidity of the membrane. Although one might expect the Euler buckling instability to limit the length of filopodia, we show through simple energetic consideratio...

The dynamics of elastic strips, i.e. long thin rods with non-circular cross-section, is analyzed by studying the solutions of the appropriate Kirchhoff equations. First, it is shown that if a naturally straight strip is deformed into a helix, the only equilibrium helical configurations are those with no internal twist and whose principal bending direction is either along the normal or the binor...

Mechanical properties of self-scrolling binormal nanohelices with a rectangular cross-section are investigated under uniaxial tensile and compressive loads using nanorobotic manipulation and Cosserat curve theory. Stretching experiments demonstrate that small-pitch nanohelices have an exceptionally large linear elasticity region and excellent mechanical stability, which are attributed to their ...

We study a minimal extension of the wormlike chain model to describe polypeptides having a-helical secondary structure. In this model the presence or absence of secondary structure enters as a scalar variable that controls the local chain bending modulus. Using this model we compute the extensional compliance of an a-helix under tensile stress, the bending compliance of the molecule under exter...

Thin films that exhibit spatially heterogeneous swelling often buckle into the third dimension to minimize stress. These effects, in turn, offer a promising strategy to fabricate complex three-dimensional structures from two-dimensional sheets. Here we employ surface topography as a new means to guide buckling of swollen polymer bilayer films and thereby control the morphology of resulting thre...

Edge effects play an important role for many properties of graphene. While most works have focused on the effects from isolated free edges, we present a novel knotting phenomenon induced by the interactions between a pair of free edges in graphene, and investigate its effect on the buckling of monolayer graphene. Upon compression, the buckling of graphene starts gradually in the form of two buc...

Response analysis of the buried pipeline subjected to reverse fault displacement is very important for design, detection and protection of buried pipelines. This paper looks at the buckling behavior of a buried pipeline subjected to reverse fault displacement in the rock stratum. Effects of internal pressure, wall thickness, fault displacement and burial depth on the buckling mode and the axial...