含残余热应力X型点阵夹层的非线性屈曲  

Nonlinear Buckling Behavior of X-Type Lattice Sandwich Structures with Thermal Residual Stress

作　　者：黄怀纬[1] 曾帝棋 梁韵逸 

机构地区：[1]华南理工大学土木与交通学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2014年第12期127-132,共6页Journal of South China University of Technology(Natural Science Edition)

基　　金：广东省自然科学基金博士启动项目(S2012040007894);国家级大学生创新创业训练计划项目(创新训练)(201210561041)

摘　　要：冲压-钎焊法是一种制备X型点阵夹层结构的有效方法,但会产生钎焊残余热应力.目前的研究未涉及残余热应力对该结构稳定性能的影响.文中采用有限元模拟了X型点阵夹层结构在压缩状态下的屈曲行为,分析中考虑了残余热应力,并计入了钎焊降温幅度及板件厚度的影响.结果表明:增加板件厚度将提高结构的屈曲临界荷载,扩大屈曲时的塑性流动区;一般而言,该结构前屈曲状态分为线性变形和非线性变形2个阶段,残余热应力的存在将强化结构的线性变形,而弱化非线性变形,但对屈曲临界荷载影响不明显;增加钎焊的降温幅度、减小板件的厚度均可增强屈曲的残余热应力效应.Folding-brazing is one of the efficient methods for fabricating X-type lattice sandwich structures. How- ever, it can cause thermal residual stress. Current researches have ignored the effect of the thermal residual stress on the structural stability. In this paper, a finite element method is adopted to simulate the buckling behavior of the X-type lattice sandwich structure in the state of compression under the thermal residual stress, and the effects of the brazing temperature drop and the plate thickness are taken into account. The results show that （ 1 ） raising the plate thickness helps to increase the buckling critical load of the structure and enlarge the plastic fluid zone of the struc- ture in the state of buckling ; （2） in general, the pre-buckling behavior of the structure consists of linear and non- linear deformations; （3） the thermal residual stress can strengthen the linear deformability but weaken the non- linear deformability, and it has little effect on the buckling critical load; and （4） both raising the dropping range of the brazing temperature and decreasing the plate thickness can enhance the thermal residual stress effect.

关 键 词：X型点阵夹层 非线性 屈曲 热应力 数值模拟 

分 类 号：TB331[一般工业技术—材料科学与工程]