检索结果-南通市图书馆

Fundamental Research 2023年第4期3卷 592-601页

作者： Bin Zhang Benny Endelt karl brian nielsen Department of Materials and Production Aalborg UniversityAalborg 9220Denmark Engineering Teaching Practice Training Center Tiangong UniversityTianjin 300387China Research and Development Lab Vestas aircoil A/SLem 6940Denmark Department of Mechanical and Production Engineering Aarhus UniversityAarhus 8000Denmark

A T-shape tube hydraulic bulge test under axial feeding force is carried out to characterize the mechanical properties of EN AW 5049-O and 6060-O aluminium *** punch displacement,T-branch height and axial compressive force are recorded online during the *** intelligent inverse identification framework combining the finite element method and numerical optimization algorithm is developed to determine material parameters by fitting simulated results to the experimental data *** identified constitutive parameters using the inverse modelling technique are compared with those determined by the theoretical analysis and uniaxial tensile *** comparison shows that the predicted bulge height and punch force based on the material parameters obtained by the three methods are different and the inverse strategy produces the smallest gap between numerical and experimental *** is possible to conclude that the hydraulic bulge test can be applied to characterize the stress-strain curve of tubular materials at the large strain scope,and the automatic inverse framework is a more accurate post-processing procedure to identify material constitutive parameters compared with the classical analytical model.

关键词： Intelligent optimization Tubular material Parameter identification Hydraulic bulge test Constitutive model

An inverse strategy to determine constitutive parameters of tubular materials for hydroforming processes

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2022年第6期35卷 379-390页

作者： Bin ZHANG Benny ENDELT Lihui LANG Yang ZHAO Shu YAN karl brian nielsen Department of Materials and Production Aalborg UniversityAalborg 9220Denmark School of Mechanical Engineering and Automation Beihang UniversityBeijing 100083China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China Department of Mechanical and Production Engineering Aarhus UniversityAarhus 8000Denmark

This paper is to determine the flow stress curve of 5049-O aluminium alloy by a tube hydraulic bulging test with fixed end-conditions. During this test, several tubular specimens are bulged under different internal pressures before their bursting, and the corresponding bulging height and wall thickness at the pole are measured. An inverse strategy is developed to determine the constitutive parameters of tubular materials based on experimental data, which combines the finite element method with gradient-based optimization techniques. In this scheme, the objective function is formulated with the sum of least squares of the error between numerical and experimental data, and finite difference approximation is used to calculate the gradient. The tubular material behavior is assumed to meet the von Mises yield criterion and Hollomon exponential hardening law. Then, constitutive parameters identification is performed by minimization of the objective function. In order to validate the performance of this framework, identified parameters are compared with those obtained by two types of theoretical models, and tensile tests are performed on specimens cut from the same tubes. The comparison shows that this inverse framework is robust and can achieve a more accurate parameter identification by eliminating mechanical and geometrical assumptions in classical theoretical analysis.

关键词： Aluminum alloy Constitutive parameter Hydraulic bulging test Inverse modelling Tubular material

Forming Process of Strong Anisotropic Material Based on the Hydrodynamic Deep Drawing with Radial Pressure

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2005年第5期21卷 733-737页

作者： Joachim DANCKERT karl brian nielsen Department of Production Aalborg University Fibigerstraede 16 DK-9220Aalborg DenmarkDepartment of ProductionAalborg University Fibigerstraede 16 DK-9220Aalborg Denmark

The hydrodynamic deep drawing process enables net shape or near net shape forming of complicated sheet metal parts made from difficultly forming materials, such as aluminium or high strength steels. Based on the conventional hydrodynamic deep drawing process, a new process, hydrodynamic deep drawing process, in which radial pressure is applied to the rim of the blank, is proposed. This new process has been analysed using FEM simulations and the obtained results have been compared with the experimental results. The material used in the experiments was Al-Mg-Si alloy, and in the FEM-simulations the elastic-plastic behaviour of Al-Mg-Si alloy was modelled using Barlat＇s 89 yield criteria.

关键词： Hydroforming Hydrodynamic deep draw Simulation Aluminum alloy

Design of an innovative multi-stage forming process for a complex aeronautical thin-walled part with very small radii

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2018年第11期31卷 2165-2175页

作者： Yao WANG Lihui LANG Ehsan SHERKATGHANAD karl brian nielsen Chun ZHANG School of Mechanical Engineering and Automation Beihang University Department of Materials and Production Aalborg University Tianjin Tianduan Press Co. LTD

In this paper, an aeronautical thin-walled part with a complex geometry which has several sharp bends and curvatures in different directions was investigated. This kind of part is difficult to be manufactured only in one stage. Therefore, an innovative multi-stage active hydroforming process assisted by the rigid forming method was designed. In addition, an optimized blank geometry is obtained. In fact, the main focused point of this paper is to propose a new small radius rounded corner forming technique and analyze the mechanism. Two kinds of forming modes of changing a big rounded corner into a small one, which are related to different tangential positions of the die in the process of calibration, are analyzed theoretically. Meanwhile, the stress and strain states of the deformation region are compared. The relationships between the minimum relative radii of rounded corners I and II in the first stage and the hydraulic pressure are calculated by the bending theory. Finally, the influences of the tensile-bulging effect and the interface condition of the double-layer sheet on the forming quality of the specimen are investigated. The achieved results can make a foundation for utilizing the proposed method in forming of thin-walled parts with very small radii.

关键词： Double-layer sheet Hydroforming Multi-stage forming Small rounded corner Tensile-bulging effect

在线全文

学校读者我要写书评

暂无评论

板液压成形及无模充液拉深技术

塑性工程学报 2002年第4期9卷 29-34页

作者：朗利辉 Joachim Danckert karl brian nielsen 张士宏康达昌 DepartmentofProduction 中国科学院金属研究所沈阳110016 哈尔滨工业大学材料科学与工程学院哈尔滨150001

板液压成形技术是液压成形技术中重要的一类 ,广泛地应用于宇航、汽车等工业领域。近年来由于新材料和复杂几何形状零件的不断出现 ,更加突出此种技术的关键性。本文就板液压成形技术原理、数值模拟技术和分类进行了研究 ,探讨了此种技... 详细信息

板液压成形技术是液压成形技术中重要的一类 ,广泛地应用于宇航、汽车等工业领域。近年来由于新材料和复杂几何形状零件的不断出现 ,更加突出此种技术的关键性。本文就板液压成形技术原理、数值模拟技术和分类进行了研究 ,探讨了此种技术将来的发展 ,介绍了基于板液压成形技术的无模充液拉深技术 ,利用实验和数值模拟技术对此技术进行了分析 ,验证了此项技术的可行性。

关键词：液压成形板成形无模充液拉深数值模拟

在线全文

学校读者我要写书评

暂无评论

先进充液柔性成形技术及其关键参数研究

中国机械工程 2006年第S1期17卷 19-22页

作者：郎利辉李涛周贤宾 Joachim Danckert karl brian nielsen 北京航空航天大学北京1000832 Aalborg University AalborgDK9220Denmark

基于所提出的具有均匀压边力并轴向加压的板材充液柔性成形技术,面向板材液压柔性成形技术的普遍规律,成形出拉深比较高的铝合金筒形件以及其他复杂形状的零件如方锥盒形件、方盒形件、轴对称锥形件等,对其中的关键技术如初始液压加载... 详细信息

基于所提出的具有均匀压边力并轴向加压的板材充液柔性成形技术,面向板材液压柔性成形技术的普遍规律,成形出拉深比较高的铝合金筒形件以及其他复杂形状的零件如方锥盒形件、方盒形件、轴对称锥形件等,对其中的关键技术如初始液压加载状态、液压加载最优路径、破裂控制等一些关键参数进行了研究和优化;考虑板平面方向性系数的影响,利用数值模拟的手段对其成形过程进行了分析,指导实验研究,得出了有益的结论。

关键词：板充液成形铝合金数值模拟液室压力

在线全文

学校读者我要写书评

暂无评论

管件内高压成形及其在汽车工业中的应用现状

中国机械工程 2004年第3期15卷 268-272页

作者：郎利辉苑世剑王仲仁王小松 Joachim Danckert karl brian nielsen Aalborg University 哈尔滨工业大学材料科学与工程学院哈尔滨150001

利用管件内高压成形技术成形的工件具有质量轻、刚度好、装配零件少、后续装配工序少等诸多优点 ,在国外该项技术已被广泛地运用到汽车、宇航领域中。介绍并探讨了管件内高压成形技术的原理、优点。

关键词：液力成形内高压成形轻体件应用

我们如何在中国做到PSY30以上:后备母猪的管理

在线全文

学校读者我要写书评

暂无评论

今日养猪业 2015年第6期 66-67页

作者： brian nielsen 杨宇钱金花连云港丹育种猪技术有限公司丹育贸易有限公司

优秀的后备母猪是保障猪场生产能力很重要的一部分,无论是从外部猪场购买还是场内自繁,都需要对其进行合理的管理,才能使其发挥出优秀的生产性能。后备母猪可通过场内自繁或从其他种猪场购买获得,这两种获得后备母猪的途径各有利弊。如... 详细信息

优秀的后备母猪是保障猪场生产能力很重要的一部分,无论是从外部猪场购买还是场内自繁,都需要对其进行合理的管理,才能使其发挥出优秀的生产性能。后备母猪可通过场内自繁或从其他种猪场购买获得,这两种获得后备母猪的途径各有利弊。如果从其他种猪场购买,后备母猪通常在4~5月龄。如果是场内自繁,后备母猪需在约3月龄时从保育舍转到后备母猪舍。

关键词：后备母猪 PSY30 母猪舍猪群健康商品猪场窝产仔数圈栏生产性能窝产活仔数母猪饲喂