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Research on Computer Simulation System of Stretch Reducing Mill for tube

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Journal of Iron and Steel Research(International) 2003年第1期10卷 24-27页

作者： XUE Zhong-ming QU Wen-qing ZHANG Yan-hua LI Shu-chun Beijing University of Aeronautics and Astronautics Beijing Institute of Mechanical Industry

The prototype,basic parameters,composition and structure of computer simulation system of stretch reducing mill for tubes were introduced.The software has an obvious style of object-oriented programming,and the modules were integrated in the simulation system.The system can optimize pass design,and it can automatically classify pass series according to the product syllabus,formulate the rolling table and simulate the rolling parameters in stretch reducing process.The simulation results were compared with the detailed technical data(used as experimental data) provided by Baotou Iron and Steel Company,and the comparison gave a clear proof of the precision of the models.

关键词： tube stretch reducing mill pass design force parameter simulation

Caval replacement with parietal peritoneum tube graft for septic thrombophlebitis after hepatectomy: A case report

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World Journal of Hepatology 2019年第1期11卷 133-137页

作者： Charlotte Maulat Léopoldine Lapierre Isabelle Migueres Xavier Chaufour Guillaume Martin-Blondel Fabrice Muscari Digestive Surgery Toulouse UniversityHospital Department of Infectious and Tropical Diseases Toulouse-Purpan University Hospital Vascular Surgery Department Toulouse-Rangueil University Hospital

BACKGROUND Caval vein thrombosis after hepatectomy is rare, although it increases mortality and morbidity. The evolution of this thrombosis into a septic thrombophlebitis responsible for persistent septicaemia after a hepatectomy has not been reported to date in the literature. We here report the management of a 54-year-old woman operated for a peripheral cholangiocarcinoma who developed a suppurated thrombophlebitis of the vena cava following a hepatectomy.CASE SUMMARY This patient was operated by left lobectomy extended to segment V with bile duct resection and Roux-en-Y hepaticojejunostomy. After the surgery, she developed Streptococcus anginosus, Escherichia coli, and Enterococcus faecium bacteraemias, as well as Candida albicans fungemia. A computed tomography scan revealed a bilioma which was percutaneously drained. Despite adequate antibiotic therapy,the patient's condition remained septic. A diagnosis of septic thrombophlebitis of the vena cava was made on post-operative day 25. The patient was then operated again for a surgical thrombectomy and complete caval reconstruction with a parietal peritoneum tube graft. Use of the peritoneum as a vascular graft is an inexpensive technique, it is readily and rapidly available, and it allows caval replacement in a septic area. Septic thrombophlebitis of the vena cava after hepatectomy has not been described previously and it warrants being added to the spectrum of potential complications of this procedure.CONCLUSION Septic thrombophlebitis of the vena cava was successfully treated with antibiotic and anticoagulation treatments, prompt surgical thrombectomy and caval reconstruction.

关键词： Bilioma Septic thrombophlebitis Septicaemia Parietal peritoneum tube graft Complete caval reconstruction Case report

The Potential of High Power Lasers for tube Cutting and Concrete Scabbling in Nuclear Decommissioning

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稀有金属材料与工程 2011年第S4期40卷 252-256页

作者： Paul Hilton Ali Khan TWI Ltd.Granta Park Cambridge CB21 6ALUK

Contaminated concrete and metal pipework presents a major nuclear decommissioning challenge in terms of the total volumes of material to be treated,the radiation levels present and the number of facilities affected.Until recently,industrial lasers have often been seen as too unreliable for use in nuclear decommissioning environments and hence their usage has been limited.The advent of solid state 'fibre' lasers has,however,provided a robust and reliable industrial tool,capable of performing not only concrete scabbling but other laser based decommissioning processes,such as cutting.Whilst concrete scabbling has been demonstrated in the laboratory,to date,no representative scale demonstration has been provided which would give industry confidence in the technique.This paper will describe the development of a laser scabbling process head,equipped with an integrated debris collection device and adaptive control system for automatic maintenance of the attitude and stand off distance of the head from the concrete surface.The results of using optical fibre delivered laser power to remove the surface of a range of representative and large scale concrete samples will be described.Using 5kW of laser power,removal rates up to 7000 cc of concrete per hour have been recorded at a removal depth of the order 10mm.The paper will also report on the results of using the same laser source,for single-sided cutting of various 304L stainless steel tubes,of diameter up to 170mm and wall thickness up to 11mm.The results show that with the right optical configuration,it is entirely possible to laser cut tubes from one side,at extremely long and safe standoff distances,if the main objective is simply to sever the tube.

关键词： lasers concrete scabbling tube cutting.

Experimental investigation and numerical simulation of large-sized aluminum tube extrusion forming

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Journal of Central South University 2008年第S2期15卷 293-295页

作者：吕亚臣骆俊廷马春荣徐岩 College of Mechanical Engineering Yanshan University Key Laboratory of Metastable Material Science and Technology Yanshan University

Large-sized aluminum tube has big section effect, aspect ratio and thin thickness, so that the extrusion technology is complex and the large specific pressure is generated in extrusion cavity. The temperature variation and velocity effect is difficult to control. The extrusion forming of large-sized aluminum tube was researched and simulated. Three-dimensional thermo-mechanical coupled finite element model was constructed and appropriate boundary conditions were given out. The results show that large-sized aluminum tube can be formed by isothermal extrusion through controlling the extrusion velocity and founding the relationship between extrusion velocity and extrusion temperature.

关键词： large-sized aluminum tube extrusion numerical simulation

Hydroforming of AZ61A tubular component with various cross sections

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Transactions of Nonferrous Metals Society of China 2009年第S2期19卷 398-402页

作者：汤泽军何祝斌刘钢苑世剑胡蓝 School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China

The effects of temperature on the mechanical properties and elongation of AZ61A tubular part were derived by uni-axial tension tests at various temperatures.Warm hydroforming of an AZ61A tubular part for passenger car was then numerically and experimentally investigated.The complete processes including bending,pre-forming and hydroforming were analyzed and discussed. Microstructure at the corner of the typical section was observed before and after the final hydroforming process.It is shown that the yielding strength,tensile strength and total elongation increase as temperature increases,while the elongation before necking decreases.The temperature range from 225℃to 250 ℃is more suitable for hydroforming of theAZ61A magnesium alloy tube with various cross sections.Pre-forming and hydroforming with high strain values are feasible at elevated temperature.Grain refinement is observed at the corner of the part after warm hydroforming.Thinning ratio analysis illustrates that non-uniform deformation at elevated temperature should be considered in process optimization to avoid severe local thinning.

关键词： tube hydroforming magnesium alloy cross section

Microstructure and Properties of 3.5 vol.%TiBw/Ti6A14V Composite tubes Fabricated by Hot-hydrostatic Extrusion

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Journal of Materials Science & Technology 2014年第7期30卷 710-714页

作者： Wencong Zhang Xueyan Jiao Yang Yu Jianlei Yang Yangju Feng School of Materials Science and Engineering Harbin Institute of Technology at Weihai

tubes of 3.5 vol,% TiB whiskers reinforced Ti6Al4V matrix composites （TiBw/Ti6Al4V） were successfully fabricated by a two-step hot-hydrostatic extrusion process：（3 extrusion at 1100 ℃ and subsequent near-β extrusion at 950℃. The dimensions of tubes were about 7 mm in diameter and 2 mm in thickness. A refined basket-weave structure in Ti6Al4V matrix was achieved at ambient temperature after the extrusion process. Besides, the original network structure formed by TiB whiskers synthesized was broken, while the TiB whiskers were preferentially aligned in the extruding direction. Meanwhile, a fibrous texture was evolved finally, resulting from partial dynamic recrystallization during the β extrusion and the involvement of α phase during the near-β extrusion. The tensile and compressive tests results showed that both the strength and ductility of the tubes were significantly improved. In particular, the tubes exhibited good mechanical properties at elevated temperatures.

关键词： Titanium matrix composites （TMCs） T/B whiskers Hot-hydrostatic extrusion tube Microstructure Mechanical properties

DETERMINATION　OF　THRESHOLD　PRESSURE　FOR　INFILTRATION　OF　LIQUID　ALUMINIUM　INTO　SHORT　ALUMINA　FIBER　PREFORM

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中国有色金属学会会刊：英文版 1996年第4期6卷 133-137页

作者： Hu Lianxi Luo Shoujing Huo Wencan(School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001) School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

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关键词： liquid infiltration effective capillary tube radius threshold infiltration pressure metal matrix composite

Modeling of laser adjustment for large diameter tubes using robotic kinematic theories

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Advances in Manufacturing 2018年第4期6卷 401-408页

作者： Pin Li Jun-Tong Xi School of Mechanical Engineering Shanghai Jiao Tong University Shanghai 200240 People's Republic of China School of Mechanical Engineering Jiangsu University Zhenjiang 212013 Jiangsu Province People's Republic of China

Laser adjustment is a new technique that employs laser forming processes to align components along specific directions. To develop a laser adjustment solution with a minimal number of bends, herein, a new modeling and calculation method that uses robotic kinematic theories is introduced. A numerical example and the corresponding laser adjustment solution are presented. The simulation results suggest that a straight tube with a flange connector can be adjusted to match the corresponding connector with three bends. Finally, the simulation results were verified using experiments. The maximum deviation was approximately 0.4 mm and the deviation of the flange connector was smaller, showing that a good adjustment quality could be achieved using the specific adjustment solution.

关键词： Laser adjustment Large diameter tube Robotic kinematics theories Production of exponential formula

Forming limits under multi-index constraints in NC bending of aluminum alloy thin-walled tubes with large diameters

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Science China(Technological Sciences) 2010年第2期53卷 326-342页

作者： YAN Jing, YANG He, ZHAN Mei & LI Heng College of Materials Science and Engineering, State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China College of Materials Science and Engineering State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi’an China

With increasing diameters of aluminum alloy thin-walled tubes (AATTs), the tube forming limits, i.e. the minimum bending factors, and their predictions under multi-index constraints including wrinkling, thinning and flattening have been being a key problem to be urgently solved for improving tube forming potential in numerical control (NC) bending processes of AATTs with large diameters. Thus in this paper, a search algorithm of the forming limits is put forward based on a 3D elastic-plastic finite element (FE) model and a wrinkling energy prediction model for the bending processes under axial compression loading (ACL) or not. This algorithm enables to be considered the effects of process parameter combinations including die, friction parameters on the multi-indices. Based on this algorithm, the forming limits of the different size tubes are obtained, and the roles of the process parameter combinations in enabling the limit bending processes are also revealed. The followings are found: the first, within the appropriate ranges of friction and clearances between the different dies and the tubes enabling the bending processes with smaller bending factors, the ACL enables the tube limit bending processes after a decrease of the mandrel ball thickness and diameters; then, without considering the effects of the tube geometry sizes on the tube constitutive equations, the forming limits will be decided by the limit thinning values for the tubes with diameters smaller than 80 mm, while the wrinkling for the tubes with diameters no less than 80 mm. The forming limits obtained from this algorithm are smaller than the analytical results, and reduced by 57.39%; the last, the roles of the process parameter combinations in enabling the limit bending processes are verified by experimental results.

关键词： forming limit NC tube bending aluminum alloy thin-walled tubes with large diameters multi-index constraints finite element method