Limits...
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

Dimensionless length Δl/L measuring the amount of rod slipping into the sliding sleeve (a) and dimensionless midspan deflection w/L (b) as functions of the dimensionless transversal load FL2/B: comparison between theoretical (black curve) and experimental results performed on three rods differing only in the thickness h, h={1.9;2.85;3.85} mm (reported as blue, red and green curves, respectively). The dripping point is marked. Symmetry breaking was observed to occur at the force reversal, but the influence on the measured forces is negligible.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4528666&req=5

RSPA20150195F7: Dimensionless length Δl/L measuring the amount of rod slipping into the sliding sleeve (a) and dimensionless midspan deflection w/L (b) as functions of the dimensionless transversal load FL2/B: comparison between theoretical (black curve) and experimental results performed on three rods differing only in the thickness h, h={1.9;2.85;3.85} mm (reported as blue, red and green curves, respectively). The dripping point is marked. Symmetry breaking was observed to occur at the force reversal, but the influence on the measured forces is negligible.

Mentions: Three photos taken during an experiment, performed on an elastic rod of cross section 24.9×3.85 mm, are reported in figure 6. Experimental results (reported for different thicknesses of the cross section) are presented in figure 7 in terms of dimensionless applied forces versus the amount of rod slipping into the sliding sleeve (figure 7a) and the midspan dimensionless deflection (figure 7b).Figure 7.


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

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

Dimensionless length Δl/L measuring the amount of rod slipping into the sliding sleeve (a) and dimensionless midspan deflection w/L (b) as functions of the dimensionless transversal load FL2/B: comparison between theoretical (black curve) and experimental results performed on three rods differing only in the thickness h, h={1.9;2.85;3.85} mm (reported as blue, red and green curves, respectively). The dripping point is marked. Symmetry breaking was observed to occur at the force reversal, but the influence on the measured forces is negligible.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

RSPA20150195F7: Dimensionless length Δl/L measuring the amount of rod slipping into the sliding sleeve (a) and dimensionless midspan deflection w/L (b) as functions of the dimensionless transversal load FL2/B: comparison between theoretical (black curve) and experimental results performed on three rods differing only in the thickness h, h={1.9;2.85;3.85} mm (reported as blue, red and green curves, respectively). The dripping point is marked. Symmetry breaking was observed to occur at the force reversal, but the influence on the measured forces is negligible.
Mentions: Three photos taken during an experiment, performed on an elastic rod of cross section 24.9×3.85 mm, are reported in figure 6. Experimental results (reported for different thicknesses of the cross section) are presented in figure 7 in terms of dimensionless applied forces versus the amount of rod slipping into the sliding sleeve (figure 7a) and the midspan dimensionless deflection (figure 7b).Figure 7.

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