有缝管冲击液压成形机理及变形规律的研究

In this project, comprehensive, systematic and profound researches are conducted on several key scientific issues of the seamed tube in Liquid Impact Forming(LIF) , with the purpose of revealing the mechanism and behaviour of the plastic deformation of seamed tubes in LIF. The researches are focused on the followings. Initially, plastic hardening phenomenon of the seamed tube in LIF is investigated, novel methodes are proposed to quantize the plastic hardening model of the basis material, welding line,heat affected zone(HAZ) of the seamed tube under the LIF condition, aiming to display its forming characters. Second, dynamics frictional characteristics of seamed tubes in LIF is probed and a novel approach to determine the coefficient of friction between tube and die in the expansion zone is presented. And then the effect of the frictional characteristics on the deformation behaviour of the seamed tube in LIF is evaluated. Afterwards, after an in-depth study of existing methods of predicting the deformation failure, a prediction model is proposed which can reflect the real structural characteristics of the seamed tube, the forming characters of LIF, the plastic hardening phenomenon and the dynamics frictional characteristics, and an approch to establish a forming limit diagram for a seamed tube in LIF is then put forward. Finally, the deformation compatibility of seamed tube in LIF is preliminary investigated and the impact of the impact pressure on the deformation compatibility is probed. And then strategy to control and utilize the deformation compatibility put forward to improve the formability of seamed tube in LIF. The research results of the project will lay the theoretical foundation for the LIF and provide scientific basis and technical support for expanding its applied scope.

本项目对有缝管冲击液压成形技术的几个关键科学问题展开系统、深入的研究，以揭示有缝管冲击液压成形机理及变形规律。具体内容包括：研究冲击液压成形环境下有缝管的动态塑性力学行为，提出构建基体、焊缝及热影响区不同环向位置的塑性硬化模型（曲线）的方法，揭示冲击液压成形特点；研究有缝管冲击液压成形时的动态摩擦特性，提出测量胀形区动态摩擦系数的新方法，揭示动态摩擦特性对有缝管冲击液压成形的影响规律；研究有缝管冲击液压成形的成形极限，建立起能综合有缝管材料特性、冲击液压成形特点、塑性硬化规律、动态摩擦特性等特征的成形极限预测模型，提出构建有缝管冲击液压成形的成形极限图的方法；初步研究冲击液压加载下有缝管的变形协调性，探索冲击液压载荷对该变形协调性的影响规律，提出合理控制变形协调性使有缝管液压成形性提高的思路。该项目将为冲击液压成形技术奠定理论基础，为冲击液压成形技术的应用提供科学依据和技术支撑。

本项目对有缝管冲击液压成形技术的几个关键科学问题展开系统、深入的研究，以揭示有缝管冲击液压成形机理及变形规律。具体内容包括：研究冲击液压成形环境下有缝管的动态塑性力学行为，提出构建基体、焊缝及热影响区不同环向位置的塑性硬化模型（曲线）的方法，揭示冲击液压成形特点；研究有缝管冲击液压成形时的动态摩擦特性，提出测量成形区动态摩擦系数的新方法，揭示动态摩擦特性对有缝管冲击液压成形的影响规律；研究有缝管冲击液压成形的成形极限，建立起能综合有缝管材料特性、冲击液压成形特点、塑性硬化规律、动态摩擦特性等特征的成形极限预测模型，提出构建有缝管冲击液压成形的成形极限图的方法；初步研究冲击液压加载下有缝管的变形协调性，探索冲击液压载荷对该变形协调性的影响规律，提出合理控制变形协调性使有缝管液压成形性提高的思路。该项目将为冲击液压成形技术奠定理论基础，为冲击液压成形技术的应用提供科学依据和技术支撑。.通过本项目，共发表标注资助的学术论文19篇：其中，英文SCI源期刊论文6篇，境外学术论文论文3篇，英文EI论文8篇，中文核心期刊2篇。获得国家授权发明专利5项，实用新型专利4项。参加境外国际学术会议3次，境内国际学术会议1次。培养博士生1名（在读）、培养硕士生7人（已毕业）。总之，完成了预定的研究内容，实现了预定的研究目标，取得了预期的研究成果，达到了预期的研究指标。