Laser forming as a springback-free and noncontact forming technique has been under active investigation over the last decade. Previous investigations are mainly focused on forming of large and thick workpieces using high power lasers, with less work on precision, micro-scale bending of small and thin sheets. In this work, a 4 W continuous wave argon ion laser is used as the energy source, and t...

A short cavity Er(3+)-doped distributed-Bragg-reflector (DBR) fiber laser with a low polarization beat frequency has been demonstrated for bending measurement. The polarization beat frequency of the DBR laser is extremely sensitive to bending and can measure curvature changes as small as 1.8 x 10(-2) m(-1). Excellent agreement between experimental and theoretical results was obtained for bendin...

Introduction: One of the major concerns in laryngeal laser surgery is the risk of airway fire. The introduction ofwrapped tubes and metal tubes has reduced the fire hazards. However, these tubes are expensive and do not provide convenient access to the surgical field. There are few laboratory studies addressing the resistance of polyvinylchloride tubes against ignition in the given circum...

the basic strategy of reduce the ductility demand and related concentrated tensions at moment resistance connections is reduce the section of the beam at connected region to column. by this method plastic hinge done at the reduced cross section and this local reduction decreases the demand of the components of connection. on this basis, in present study a new beam-to-column moment connection wi...

Connections of I-beam to CHS column in buildings are either simple (fin plate connection, directly welded beam connections) and flexible or rather complex rigid (external diaphragm connections). The passing-through I-beam-to-CHS connections made by laser cutting technology offer a solution that limit the amount welding enhance stiffness joint. An experimental campaign has been carried out inves...

Abstract As the first study in field regarding CB, this paper investigates implications of interchanging between RDB and CB through manufacturing bends with various angles difference two methods form springback, cross section compression widening, shape wall thinning/thickening. The experiments conducted consists aluminum alloy 6060-T4 round tubes 60 mm diameter 3 thickness, bent around 222 rad...

Laser bending of tubes is a process in which laser-induced thermal distortion is used to bend tubes without hard tooling or external forces. Mechanisms of the process are examined to better understand the deformation characteristics such as wall thickness variation, cross-section ovalization, bending radius, and asymmetry. Factors important to these characteristics are experimentally and numeri...

Pure bending of single-walled carbon nanotubes between (5,5) and (50,50) is studied using molecular dynamics based on the reactive bond order potential. Unlike smaller nanotubes, bending of (15,15) and larger ones exhibits an intermediate deformation in the transition between the buckled and fully kinked configurations. This transient bending regime is characterized by a gradual and controllabl...