Rods In Terms Research Articles

Energy absorption of braiding pultrusion process composite rods

Composite body structures are now commonly used in road and rail vehicles, ships and submarines, aircraft and spacecraft due to their capability to effectively absorb high kinetic energy to weight ratio. One such structure designed as an energy device with pre-determined properties is a braided pultruded process (BPP) composite rod of either circular or square cross-section. This paper reports the results of an investigation on circular BPP rods and unidirectional pultruded process rods in epoxy matrix subjected to compressive loading. Test results depict BPP rods to have superior properties in comparison to the unidirectional rods in terms of energy absorption capability that is manifested through well-defined progressive crushing failure mechanisms. Generally the rods' fracture and complete failure mechanisms show distinct creation of buckling zone, followed by generation of fronds as the wedge area increases with every augmentation of applied load. Fracture morphology related to overall performance characteristics is discussed through the step-by-step analysis of microphotography. The specific energy absorption property is shown to be best achieved in carbon/carbon (C/C) BPP followed by glass/carbon (G/C) rod combination and then the glass/glass (G/G) BPP rods. The latter (G/G), although worst performer of all the rods in terms of energy characteristics, still outperforms the documented best tubes made of Kevlar fibres, steel and aluminium. On average, the carbon/carbon (C/C) BPP rod's specific energy absorption is between 35% and 55% more than the nearest comparable tubes.

Interfaces in solutions of randomly charged rods

We study the interfacial properties of systems containing like-charged rods with charge fluctuations along their length. We show that it is possible to describe clusters of rods in terms of the sum of a bulk free energy and a surface free energy. It is not obvious that this is valid for electrostatic systems, since the interactions are long-ranged, and the effective interactions between rods are not pairwise-additive.

Local rotations, topological invariant for thin rods, and supercoiling of DNA

We describe a scheme for calculation of the topological invariant for closed twisted thin rods in terms of the rotation matrices for local deformations. The technique is applied to the analysis of conformations in closed circular supercoiled DNA.

Comparison Between Square-ended Distraction Rods and Standard Round-ended Distraction Rods in the Treatment of Thoracolumbar Spinal Injuries A Statistical Analysis

This is a retrospective clinical and roentgenographic study of two different types of instrumentation used in the treatment of thoracic and lumbar spinal fractures. Dual square-ended distraction rods contoured into lordosis produced improved results when compared with round-ended distraction rods in terms of both the degree of reduction obtained on the operating table and preventing recollapse of the fracture in the ensuing month. The importance of restoring lordosis was more apparent in the thoracolumbar junction and lumbar spine than in the thoracic region.

On the solution of the equilibrium problem of rods in terms of generalized stresses and displacements

On the solution of the equilibrium problem of rods in terms of generalized stresses and displacements