摘要
空心薄壁件是高新技术工程领域越来越青睐的轻体结构件之一。而起皱失稳问题是薄壁件成形所面临的主要质量问题。因此,关于空心薄壁件成形过程中的塑性失稳起皱预测研究就显得尤为重要。本文基于薄壁件成形失稳起皱试验和理论研究现状,提出基于管材缩径成形研究薄壁件起皱失稳的共性规律。通过建立管材缩径起皱失稳时刻对应形貌的平衡微分方程,求解了缩径管材的临界失稳外压解析表达式。结合塑性成形理论分析了临界失稳主应变的分布特征,探讨了成形几何条件、材料参数等成形因素对零件成形抗皱性能的影响。结合工艺试验,证实了各参数的影响权重。通过本文的理论和试验分析最终确定:综合了材料强化系数和硬化指数影响的塑性切线模量对材料抗皱性的影响比重大于屈服应力对材料抗皱性的影响比重,对材料最终的起皱程度起主导作用。
Hollow thin-walled parts is a kind of hollow light structure which is more and more favourate in new and high technology engineering field. The main quality problem in the thin-walled parts forming is the wrinkling buckling problem. Therefore,the hollow thin-walled plastic instability wrinkling prediction research is extremely important. Based on the status about test method and theoretical research of wrinkling instability about thin-wall parts forming,the tube outer pressure compression forming are selected to study the common rules in wrinkling buckling. The analytical formulas are obtained by solving the equilibrium differential equations established at the moment of tube buckling with certain wrinkle morphology under the external pressure condition. The distribution characteristics of main critical buckling strains are analyzed by combining the plastic forming theory with the wrinkling instability theory; also the influences of the forming conditions and material property to the wrinkle-resistance property are discussed. The effect weight of each parameter is determined finally through the tube outer pressure compression forming process test. Through the theory and experiment analysis of this paper,it is known that the effect weight of plastic tangent modulus which includes the coefficient of intensification and hardening index to wrinkle-resistance property is larger than that of yield stress to the wrinkle-resistance property of tube.
出处
《燕山大学学报》
CAS
北大核心
2017年第6期510-515,共6页
Journal of Yanshan University
基金
国家自然科学基金资助项目(51605420)
燕山大学博士基金资助项目(B935)
关键词
薄壁件
起皱失稳共性规律
管材缩径
hollow thin-walled parts
wrinkling instability common rules
tube outer pressure compression forming
