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Self-encapsulation, or the 'dripping' of an elastic rod.

Bosi F, Misseroni D, Dal Corso F, Bigoni D - Proc. Math. Phys. Eng. Sci. (2015)

Bottom Line: Dripping seems at a first glance to be impossible and definitely cannot occur in the presence of 'ordinary' constraints (such as simple supports or clamps) at the ends of the span.This phenomenon is indeed demonstrated (both theoretically and experimentally) to occur when at least one of the constraints at the ends of the rod is a sliding sleeve.This mechanical device generates a configurational force, causing the dripping of the rod, in a fully elastic set-up.

View Article: PubMed Central - PubMed

Affiliation: DICAM , University of Trento , via Mesiano 77, Trento 38123, Italy.

ABSTRACT

A rod covering a fixed span is loaded at the middle with a transverse force, such that with increasing load a progressive deflection occurs. After a certain initial deflection, a phenomenon is observed where two points of the rod come in contact with each other. This is defined as the 'dripping point' and is when 'self-encapsulation' of the elastic rod occurs. Dripping seems at a first glance to be impossible and definitely cannot occur in the presence of 'ordinary' constraints (such as simple supports or clamps) at the ends of the span. However, the elastica governs oscillating pendulums, buckling rods and pendant drops, so that a possibility for self-encapsulation might be imagined. This phenomenon is indeed demonstrated (both theoretically and experimentally) to occur when at least one of the constraints at the ends of the rod is a sliding sleeve. This mechanical device generates a configurational force, causing the dripping of the rod, in a fully elastic set-up.

No MeSH data available.


Related in: MedlinePlus

Sketch of the structure showing dripping of an elastic rod. An elastic planar rod, of bending stiffness B, is constrained with a frictionless sliding sleeve at both ends. The distance between the two constraints, L is fixed, but the rod between the two constraints has a variable length, function of the transverse load F applied at midspan.
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RSPA20150195F2: Sketch of the structure showing dripping of an elastic rod. An elastic planar rod, of bending stiffness B, is constrained with a frictionless sliding sleeve at both ends. The distance between the two constraints, L is fixed, but the rod between the two constraints has a variable length, function of the transverse load F applied at midspan.

Mentions: The key point in solving the above-formulated self-encapsulation problem lies in the choice of the constraints at the ends of the span, namely, a couple of (perfectly smooth) sliding sleeves (figure 2). In the presence of a bending moment, the sliding sleeve has been shown to generate an ‘Eshelby-like’ or ‘configurational’ force [7–10], which provides the longitudinal compression needed to produce dripping. A similar mechanical system has already been studied, but without considering the configurational force [11,12], and thus dripping has remained undiscovered.Figure 2.


Self-encapsulation, or the 'dripping' of an elastic rod.

Bosi F, Misseroni D, Dal Corso F, Bigoni D - Proc. Math. Phys. Eng. Sci. (2015)

Sketch of the structure showing dripping of an elastic rod. An elastic planar rod, of bending stiffness B, is constrained with a frictionless sliding sleeve at both ends. The distance between the two constraints, L is fixed, but the rod between the two constraints has a variable length, function of the transverse load F applied at midspan.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4528666&req=5

RSPA20150195F2: Sketch of the structure showing dripping of an elastic rod. An elastic planar rod, of bending stiffness B, is constrained with a frictionless sliding sleeve at both ends. The distance between the two constraints, L is fixed, but the rod between the two constraints has a variable length, function of the transverse load F applied at midspan.
Mentions: The key point in solving the above-formulated self-encapsulation problem lies in the choice of the constraints at the ends of the span, namely, a couple of (perfectly smooth) sliding sleeves (figure 2). In the presence of a bending moment, the sliding sleeve has been shown to generate an ‘Eshelby-like’ or ‘configurational’ force [7–10], which provides the longitudinal compression needed to produce dripping. A similar mechanical system has already been studied, but without considering the configurational force [11,12], and thus dripping has remained undiscovered.Figure 2.

Bottom Line: Dripping seems at a first glance to be impossible and definitely cannot occur in the presence of 'ordinary' constraints (such as simple supports or clamps) at the ends of the span.This phenomenon is indeed demonstrated (both theoretically and experimentally) to occur when at least one of the constraints at the ends of the rod is a sliding sleeve.This mechanical device generates a configurational force, causing the dripping of the rod, in a fully elastic set-up.

View Article: PubMed Central - PubMed

Affiliation: DICAM , University of Trento , via Mesiano 77, Trento 38123, Italy.

ABSTRACT

A rod covering a fixed span is loaded at the middle with a transverse force, such that with increasing load a progressive deflection occurs. After a certain initial deflection, a phenomenon is observed where two points of the rod come in contact with each other. This is defined as the 'dripping point' and is when 'self-encapsulation' of the elastic rod occurs. Dripping seems at a first glance to be impossible and definitely cannot occur in the presence of 'ordinary' constraints (such as simple supports or clamps) at the ends of the span. However, the elastica governs oscillating pendulums, buckling rods and pendant drops, so that a possibility for self-encapsulation might be imagined. This phenomenon is indeed demonstrated (both theoretically and experimentally) to occur when at least one of the constraints at the ends of the rod is a sliding sleeve. This mechanical device generates a configurational force, causing the dripping of the rod, in a fully elastic set-up.

No MeSH data available.


Related in: MedlinePlus