Bend radius

About: Bend radius is a research topic. Over the lifetime, 3303 publications have been published within this topic receiving 35415 citations. The topic is also known as: minimum bend radius.

Prediction of wrinkling in thin-walled tube push-bending process using artificial neural network and finite element method:

Abstract: The tube push bending process is a method that is mainly used to bend thin-walled tubes with a small bending radius. In this paper, artificial neural networks (ANNs) are used to predict the creation of wrinkling in a tube during the bending process. Since training the neural network involves many datasets and all of these data are difficult to generate using experiments, a credible finite element (FE) model is developed. The results obtained from the FE model are validated by conducting experimental tests. The results of the FE simulations are used to train, test, and validate the ANN models. Backpropagation neural networks based on the Levenberg–Marquardt algorithm are constructed using five design parameters including: relative bending radius; relative tube diameter; friction between die and tube; friction between tube and mandrel; and pressure as the network inputs and the maximum wrinkling height (MWH) as the single output. Two different ANN models are trained for two types of tube materials: brass an...

Numerical Modeling of S-Band EDFA Based on Distributed Fiber Loss

Abstract: A numerical model for the analysis and design of S-band erbium-doped fiber amplifiers has been developed. The model is able to accurately predict the amplifier performances by taking into account the amplified spontaneous emission suppression due to the bending, as well as leakage losses of the fiber used as active medium. The model has been validated by comparing numerical and experimental data of bending loss, amplifier gain, and noise figure of an S-band optical amplifier based on a depressed-cladding erbium-doped fiber. A good agreement has been verified by varying fiber bending radius, input signal power, and wavelength. The model has been then applied to the optimization of the amplifier performances for wavelength-division multiplexer applications. The numerical results show that 20-25 dB gain can be achieved over a 25-30 nm range centered in a different part of the S-band from 1460 to 1525 nm, just by changing the bending radius and the length of a depressed-cladding fiber.

Press working method for magnesium alloy and press working device

Abstract: PROBLEM TO BE SOLVED: To provide a press working method and a press working device for a magnesium alloy by which the metal plate of magnesium alloy is worked with a small bending radius by bending it less times while preventing generation of a crack. SOLUTION: While a plate material 1 to be worked consisting of magnesium alloy, is heated to a working temp. of >=200 deg.C, bending that is set so that successively smaller bending radius is repeated at least two times, to obtain the magnesium alloy having a prescribed bending radius. Concretely, the plate material 1 to be worked is bent at a working temp. of >=200 deg.C at a bending rate of 80 to 100%, affording a primary worked part 7. The primary worked part 7 is bent at a working temp. of >=200 deg.C at a vending rate of 100 to 150%, affording a required press worked part 11, that has a prescribed small radius and the crack is not caused.

Highly efficient Yb-free Er-La-Al doped ultra-low NA large mode area single-trench fiber laser.

Abstract: We demonstrate a 60µm core diameter Yb free Er-La-Al doped single-trench fiber having a 0.038 ultra-low-NA, fabricated using conventional MCVD process in conjunction with solution doping technique. Numerical simulations predict an effective single mode operation with effective area varying from 1,820µm2 to 1,960µm2 (taking bend-induced modal distortion into account) for different thicknesses of trenches and resonant rings at a constant bend radius of 25cm. Moreover, all solid structure favors easy cleaving and splicing. Experimental measurements demonstrate a robust effective single mode operation. Furthermore, with a 4%-4% laser cavity, this fiber shows a record efficiency of 46% with respect to the absorbed pump power.