Numerical and experimental study on rotary draw bending of aluminium alloy tubes

2011 ◽  
Vol 2 (1) ◽  
pp. 33-38 ◽  
Author(s):  
L. Lăzărescu

Abstract In this paper a 3D finite element model of the bending process for circular aluminium alloy tube has been built using the explicit code eta/Dynaform and validated by comparing the experiments. The experiments were carried out by using a hand bender with the same bending principle as a rotary draw numerical controlled (NC) bender. The relationship between quality parameters of bent tubes, in terms of cross-section distortion and wall thinning, and the angular position along the bent tube is discussed experimentally in combination with FE simulation. Then, the effects of bending radius (R) are investigated using simulation of the bending process based on the finite element model. The results show that with the increase of bending radius, the cross-section degradation factor (Ψ) and wall thinning degree (ξ) decreases rapidly.

2011 ◽  
Vol 299-300 ◽  
pp. 432-435
Author(s):  
Han Xiao ◽  
Shi Hong Zhang ◽  
Jin Song Liu

A warm pre-tension rotation bending process is presented to bend the AZ31 profile. A 3D elastic-plastic thermo-mechanical coupled finite element model is established to investigate the effect of forming temperature on the geometric accuracy of the profile. The results indicate that with increasing forming temperature, the springback angles decrease from 8.37° to 7.2°; the bending radii decrease from 90.69 mm to 89.67 mm; the cross-section distortion of the bent profile increases.


2012 ◽  
Vol 482-484 ◽  
pp. 314-317
Author(s):  
Han Xiao ◽  
Yu Chun Dang ◽  
Shi Hong Zhang ◽  
De Hong Lu

A 3D elastic-plastic thermo-mechanical coupled finite element model of AZ31 Mg alloy profile during warm bending process was established. The effect of bending angle on the geometric accuracy of the profile was investigated. The results indicate that with increasing bending angle, the springback angles increase from 7.56° to 8.27°; the bending radii decrease from 90.15 mm to 90.01 mm; the cross-section distortion of the bent profile increases.


Author(s):  
Kai Jokinen ◽  
Erno Keskinen ◽  
Marko Jorkama ◽  
Wolfgang Seemann

In roll balancing the behaviour of the roll can be studied either experimentally with trial weights or, if the roll dimensions are known, analytically by forming a model of the roll to solve response to imbalance. Essential focus in roll balancing is to find the correct amount and placing for the balancing mass or masses. If this selection is done analytically the roll model used in calculations has significant effect to the balancing result. In this paper three different analytic methods are compared. In first method the mode shapes of the roll are defined piece wisely. The roll is divided in to five parts having different cross sections, two shafts, two roll ends and a shell tube of the roll. Two boundary conditions are found for both supports of the roll and four combining equations are written to the interfaces of different roll parts. Totally 20 equations are established to solve the natural frequencies and to form the mode shapes of the non-uniform roll. In second model the flexibility of shafts and the stiffness of the roll ends are added to the support stiffness as serial springs and the roll is modelled as a one flexibly supported beam having constant cross section. Finally the responses to imbalance of previous models are compared to finite element model using beam elements. Benefits and limitations of each three model are then discussed.


2014 ◽  
Vol 945-949 ◽  
pp. 1180-1184
Author(s):  
Yao Guo Xie

A finite element model ships, for example design test condition of the underwater explosion, selection of explosive package quantity is 1000KG TNT, the explosive location along the direction of the ship with the bow, midship and stern, the angle of attack in three exploded cross section have 90 degrees, 60 degrees, 45 degrees, 30 degrees and 0 degrees. According to the current standard to calculate the ship damage radius, critical radius and safety radius of specific values under the effect of underwater explosion, interpolation calculation and draw the envelope. Analysis shows that the vitality of ships and shock-resistance is not only related to the explosive distance, also related to the attack position.


2014 ◽  
Vol 629 ◽  
pp. 498-502 ◽  
Author(s):  
K.A. Kamarudin ◽  
Al Emran Ismail

This paper explains the utilisation of finite element model to analyse the ballistic limit of aluminium alloy 7075-T6 impacted by 8.33 g with 12.5 mm radius rigid spherical projectiles. This numerical study was compared with the results obtained experimentally. During impact, the targets were subjected to either non- or uniaxial- pretension and the projectile travelled horizontally to the target. It was observed that pretensioned targets were more vulnerable, which reduced the ballistic limit. The existence of harmful failures owing to pretension impact was ascertained and compared with the non-pretension targets.


2021 ◽  
Author(s):  
P. Stabile ◽  
F. Ballo ◽  
M. Gobbi ◽  
G. Previati

Abstract This work focuses on the development of an innovative design methodology for lightweight wheels of road vehicles. In particular, the activity is carried out for the specific case of a wheel designed for an ultra-efficient vehicle for Shell Eco-marathon competition, with the aim of finding preliminary design solutions. A simplified finite element model of the tire structure is employed for an accurate modelling of the forces acting at the tire/rim interface. The material properties of the tire structure are identified by means of experimental tests. The computed tire/rim force distribution is applied to the rim exploiting a simplified finite element model of the wheel rim. A multi-objective optimization problem is formulated, based on mass and compliance minimization. Several wheel design layouts are investigated, which differ in terms of number of spokes (i.e. 3, 5 and 7), spokes layout (i.e. straight and Y-shape) and spokes cross section (i.e. rectangular, C and I). Geometric quantities related to the cross section dimensions of the spokes and to the rim thickness are optimized. Design constraints related to structural stiffness and elastic stability (both global and local buckling) are taken into account. The developed finite-element based model of the wheel is used to train a set of neural networks to approximate the objective functions and the design constraints to reduce the computational effort. A multi-objective genetic algorithm is adopted to obtain the Pareto-optimal solutions. The implemented method has proved to be a valuable tool to support design engineers in taking critical decisions in the early stages of the design process.


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