Research on springback characteristic in flexible multi-points 3D stretch-bending process

Author(s):  
Song Gao ◽  
Tonggui He ◽  
Qihan Li ◽  
Yingli Sun ◽  
Jicai Liang

The problem of springback is one of the most significant factors affecting the forming accuracy for aluminum 3D stretch-bending parts. In order to achieve high-efficiency and high-quality forming of such kind of structural components, the springback behaviors of the AA6082 aluminum profiles are investigated based on the flexible multi-points 3D stretch-bending process (3D FSB). Firstly, a finite element simulation model for the 3D FSB process was developed to analyze the forming procedure and the springback procedure. The forming experiments were carried out for the rectangle-section profile to verify the effectiveness of the simulation model. Secondly, the influence of tension on springback was studied, which include the pre-stretching and the post-stretching. Furthermore, the influences of the bending radius and bending sequence are revealed. The results show that: (1) The numerical model can be used to evaluate the effects of bending radius and process parameters on springback in the 3D FSB process effectively. (2) The pre-stretching has little effect on the horizontal springback reduction, but it plays a prominent role in reducing the springback in the vertical direction. (3) The increase of bending deformation in any direction will lead to an increase of springback in its direction and reduce the springback in the other direction. Besides, it reduces the relative error in both directions simultaneously. This research established a foundation to achieve the precise forming of the 3D stretch-bending parts with closed symmetrical cross-section.

2013 ◽  
Vol 470 ◽  
pp. 330-334
Author(s):  
Bing Chen ◽  
Hai Hai Lin ◽  
Rui Juan Guo ◽  
Jian Hua Shu

Based on the fundamental assumption of the stretch-bending straightening theory and applying the elastoplastic theory, the paper analyzes and deduces the distribution and change of stress and strain of strip in the bending springback, raising that bending unloading will increase the elongation of the neutral layer of the strip. Then, through the conditions set-up of the finite element simulation model and results of data analysis, we found the effect of different tension and bending degree on the elongation for the neutral layer of the cold strip in process of unloading, and this kind of influence is described quantitatively.


2011 ◽  
Vol 365 ◽  
pp. 28-32 ◽  
Author(s):  
Ke Feng Liang ◽  
Ze Zhong Chen ◽  
Shui Miao Wang ◽  
Jie Zheng

With the adoption of ABAQUS/Explicit as the simulation platform, a 3D finite element model has been established to simulate the stretch bending of square tube aluminum profile which is used as the door frame of fork lifter. Four characteristic points are put forward to evaluate the distortion of cross section during deformation, and the influence to distortion of cross section from some key parameters, such as bending radius and thickness of profile, is analyzed. An orthogonal experiment is designed to evaluate the influence to deformation from other forming parameters, including preload, fill rally and filling pressure which occurred in the stretch bending process. Then neural network based response surface method and genetic algorithm are used to optimize the parameters mentioned above. Finite element simulation proved that the optimized result is valuable to reduce the distortion of cross section of profile and improve formability.


2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199497
Author(s):  
Guanghui Xu ◽  
Shengkai Su ◽  
Anbin Wang ◽  
Ruolin Hu

The increase of axle load and train speed would cause intense wheelrail interactions, and lead to potential vibration related problems in train operation. For the low-frequency vibration reduction of a track system, a multi-layer track structure was proposed and analyzed theoretically and experimentally. Firstly, the analytical solution was derived theoretically, and followed by a parametric analysis to verify the vibration reduction performance. Then, a finite element simulation is carried out to highlight the influence of the tuned slab damper. Finally, the vibration and noise tests are performed to verify the results of the analytical solution and finite element simulation. As the finite element simulation indicates, after installation of the tuned slab damper, the peak reaction force of the foundation can be reduced by 60%, and the peak value of the vertical vibration acceleration would decrease by 50%. The vibration test results show that the insertion losses for the total vibration levels are 13.3 dB in the vertical direction and 21.7 dB in the transverse direction. The noise test results show that the data of each measurement point is smoother and smaller, and the noise in the generating position and propagation path can be reduced by 1.9 dB–5.5 dB.


SAGE Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215824402198925
Author(s):  
Isidoro Guzmán-Raja ◽  
Manuela Guzmán-Raja

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.


Author(s):  
Banu Çalış Uslu ◽  
Ertuğ Okay ◽  
Erkan Dursun

AbstractCurrently, rapidly developing digital technological innovations affect and change the integrated information management processes of all sectors. The high efficiency of these innovations has inevitably pushed the health sector into a digital transformation process to optimize the technologies and methodologies used to optimize healthcare management systems. In this transformation, the Internet of Things (IoT) technology plays an important role, which enables many devices to connect and work together. IoT allows systems to work together using sensors, connection methods, internet protocols, databases, cloud computing, and analytic as infrastructure. In this respect, it is necessary to establish the necessary technical infrastructure and a suitable environment for the development of smart hospitals. This study points out the optimization factors, challenges, available technologies, and opportunities, as well as the system architecture that come about by employing IoT technology in smart hospital environments. In order to do that, the required technical infrastructure is divided into five layers and the system infrastructure, constraints, and methods needed in each layer are specified, which also includes the smart hospital’s dimensions and extent of intelligent computing and real-time big data analytic. As a result of the study, the deficiencies that may arise in each layer for the smart hospital design model and the factors that should be taken into account to eliminate them are explained. It is expected to provide a road map to managers, system developers, and researchers interested in optimization of the design of the smart hospital system.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Oleksandr Shtyka ◽  
Viktar Shatsila ◽  
Radoslaw Ciesielski ◽  
Adam Kedziora ◽  
Waldemar Maniukiewicz ◽  
...  

The photocatalytic activity of TiO2 depends on numerous factors, such as the chemical potential of electrons, charge transport properties, band-gap energy, and concentration of surface-active sites. A lot of research has been dedicated to determining the properties that have the most significant influence on the photocatalytic activity of semiconductors. Here, we demonstrated that the activity of TiO2 in the gas-phase reduction of CO2 is governed mainly by the desorption rate of the reaction intermediates and final products. This indicates that the specific surface area of TiO2 and binding strength of reaction intermediates and products are the main factors affecting the photocatalytic activity of TiO2 in the investigated process. Additionally, it was shown that rutile exhibits higher photocatalytic activity than anatase/rutile mixtures mainly due to its high efficiency in the visible portion of the electromagnetic spectrum.


2014 ◽  
Vol 620 ◽  
pp. 417-423 ◽  
Author(s):  
Zhong Wen Xing ◽  
Zhi Wei Xu ◽  
Hong Liang Yang ◽  
Cheng Xi Lei

A finite element model of high-strength rectangular section steel tube in rotary-draw bending is established to study the stress and strain in the bending process. Based on control variate method, this paper analyzes the influence laws of three geometric parameters on rotary-draw bending. The results show that bending radius is the most important factor, forming property increases significantly with the increase of bending radius, the trends of cracking and wrinkling are all decreased. The thickness of wall has influence on the strain of inwall, thinner tube may cause crack and wrinkle. Fillet radius has no effect on ektexine, the strain of inwall decreases slightly with the increase of fillet radius.


2012 ◽  
Vol 503-504 ◽  
pp. 824-827
Author(s):  
Chun Qiang Jia ◽  
Wei Li ◽  
Ling Yu

To solve the problem of support speed of hydraulic support flipper, the match relations between the flipper throttle control and shearer cutting coal speed are analyzed, the AMESim simulation model of the throttle optimal control for hydraulic support flipper jack is established, the simulation results show that flipper can be supported timely by speed optimal control of flipper jack which improve the reliability of the system and provide certain theory basis to meet the miner safety and high efficiency production.


2021 ◽  
pp. 2150319
Author(s):  
Li Bo Wang ◽  
Cheng Zhi Ma ◽  
Jiu Hui Wu ◽  
Chong Rui Liu

The underwater acoustic siphon effect is proposed in this work, which aims to reveal the basic physical mechanism of high-efficiency sound absorption in meta-structures composed of multiple detuned units. Furthermore, the influence of the area ratio on the underwater acoustic siphon effect is then investigated by finite element simulation (FES) and theoretical calculation. On this basis, a meta-structure with the maximum absorption coefficient of almost 100% and average absorption coefficient of 80% at 600–1400 Hz is achieved. The underwater acoustic siphon effect could provide a better understanding of high-efficiency sound absorption and offer a new perspective in controlling underwater noises.


2021 ◽  
Author(s):  
XueTao Wei ◽  
caixue yue ◽  
DeSheng Hu ◽  
XianLi Liu ◽  
YunPeng Ding ◽  
...  

Abstract The processed surface contour shape is extracted with the finite element simulation software, and the difference value of contour shape change is used as the parameters of balancing surface roughness to construct the infinitesimal element cutting finite element model of supersonic vibration milling in cutting stability domain. The surface roughness trial scheme is designed in the central composite test design method to analyze the surface roughness test result in the response surface methodology. The surface roughness prediction model is established and optimized. Finally, the finite element simulation model and surface roughness prediction model are verified and analyzed through experiment. The research results show that, compared with the experiment results, the maximum error of finite element simulation model and surface roughness prediction model is 30.9% and12.3%, respectively. So, the model in this paper is accurate and will provide the theoretical basis for optimization study of auxiliary milling process of supersonic vibration.


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