Contact Mechanics of a Thin, Tensioned, Translating Tape With a Grooved Roller

Traction between a thin tensioned tape and a grooved roller could be significantly affected by lubrication effects that stem from the air entrainment into the tape–roller interface. An experimental and theoretical investigation was carried out to investigate the tape contact with a grooved roller. The tape-to-roller spacing was measured in a modified tape drive at various operational speed and tension values. The experiments showed that increasing tape tension and tape speed causes the tape-to-land spacing to increase. This unusual result is shown to be due to the tape bending laterally into the grooves. The effects of air entrainment on tape deflection and contact with a land is modeled by using shell theory, air lubrication, and contact mechanics. A relatively wide range of design parameters (groove width, land width) and device parameters (velocity and tension) were simulated to characterize the traction of a thin tape over a grooved roller. It was shown that air lubrication effects reduce the contact force; however, the underlying effects of tape mechanics are not entirely eliminated. This work shows that in order to characterize the mechanics of thin tape over grooved rollers, the tape deflection in the lateral direction should be included in the analysis.

Flexible Thermosetting Pipe

The typified as flexible thermosetting pipe, is a new product, developed initially in response to the need for a non-metallic replacement for steel pipe used for oil and gas productions. This product may use for high pressure down-hole applications in which the pipe could repeatedly transported onto a drum. The proposed pipe comprise an internal thermoplastic layer play as liner and a fluid-tight cover, and one or more dual-helical wounding tape stacks applied to the internal liner for absorbing axial and bending loads. The tape stacks are wrapped helically onto the pipe structure with adjacent gaps between wrappings tape to reduce the pressure integrity of the tubular pipe structure. The composite tape stacks are formed from a plurality of thin tape strips and are bonded to each other within a stack. All the layers are manufactured from composite material consisting of highly noncorrosive epoxied matrix reinforced by long continuous fibers. Thus, the proposed flexible pipe designed to be stand alone with thermoplastic liner over-wound with one or more of an epoxy-based structural thermosetting laminate. To this aim, a straightforward simulations of thermosetting pipe is developed via using ANSYS software. Apart from possessing an accurate operational condition, on account of its simplicity the proposed simulation seems also very suitable for further developing and prototyping purposes. Finally, it has been shown that the proposed thermosetting pipe, which partially attains some classical characteristic of both offshore and onshore pipeline by a different line of reasoning, is may serve as a reference in designing flexible pipe.

Modeling the Traction of a Thin Tape Guided by a Grooved Roller

The Stribeck effect describes the velocity dependence of the friction coefficient between moving components [9]. In the case of an axially translating tape, supported by a roller, air entrainment can cause reduction in the contact pressure, and hence in the tractive capacity of the interface [5]. Grooved rollers are used to prevent excessive built-up of air pressure [6,7,8,1,2]. In this work, tribology and mechanics of a tape-grooved-roller interface is modeled in order to investigate the traction as a function of tape speed, tension and groove size.

Texture Formation in Thin Tapes from Ni-Based Ternary Alloys with Cr, W, Mo and V

Texture, structure, and magnetic and mechanical properties of thin tape substrates fabricated of ternary nickel alloys with chromium, tungsten, molybdenum, and vanadium have been investigated. It has been shown that in Ni93.8Cr4.0Mo2.2, Ni88.5Cr6.2V5.3and Ni88.4Cr9.2W2.4 alloys a sharp cube texture can form, which is stable up to high annealing temperatures. In the Ni87.6Cr8.0Mo4.4alloy, other weak orientations are present, along with the strong cube component. The possibility of obtaining a sharp cube texture after primary recrystallization is controlled by the quantitative relationship between the texture components in a cold-rolled tape, which is determined by the method of orientation-distribution functions. Three alloys studied are non-magnetic at 77 K.