管轴压成形失稳起皱力学过程的研究  

RESEARCH ON MECHANICAL MODEL OF BUCKLING IN TUBE AXIAL COMPRESSIVE FORMING PROCESS

作　　者：孙志超[1] 杨合[1] 

机构地区：[1]西北工业大学材料科学与工程学院,西安710072

出　　处：《机械工程学报》2003年第6期110-113,共4页Journal of Mechanical Engineering

基　　金：国家自然科学基金(59775055);西北工业大学博士论文创新基金(G14109)资助项目

摘　　要：管轴压成形的先进性、优势及成形过程的成功实施受到变形区开裂和传力区起皱等失稳因素的制约,为此采用理论解析与试验相结合的方法,对失稳起皱的力学过程、影响因素及影响规律进行了研究,并给出了失稳判据,以实现稳定成形时变形参数的取值范围的确定。研究表明:成形过程的失稳起皱受到几何参数、材料参数及摩擦边界条件的共同作用。其中,模具圆角曲率半径是决定性因素,并且存在一个最大和最小圆角半径区域使成形过程顺利进行而不发生失稳起皱;增大管坯材料硬化指数,减小相对厚度及接触面的摩擦,有利于减少失稳的发生。对牌号为5052,原始管平均直径d_0=31.0mm,41.0mm铝管的应用表明所提出的判据是可靠实用的。The advantage of tube axial compressive forming and whether to realize forming process depend on whether to produce the tearing or buckling failures during the forming process. Based on minimum energy principle for plastic forming, the buckling machenism and effects of forming parameters on it are investigated by theoretical analysis and experiment, and the criterion for bucking failure is developed which can be used to determine proper parameters for stable forming. The results show that the effect parameters of buckling failure includes geometrical parameters, material properties, and friction condition. The main governing parameter that controls the success of forming process without buckling is the correct choice of die radius, and existing a maximum radius and a minimum radius, in this range no buckling failure happens. With the high value of material strain hardening exponent n and the low value of the thickness to diameter ratio, it is possible to prevent buckling failure, at the same time decreasing the friction condition is helpful to prevent buckling. The criterion for bucking failure purposed in this paper is used in tube axial compressive forming process for aluminum tube blanks with brand No 5052, d0=31.0 mm, 41.0 mm and the results show that criterion is reliable and practical.

关 键 词：管轴压成形 失稳 起皱 力学模型 模具圆角曲率半径 

分 类 号：TG386.43[金属学及工艺—金属压力加工]