摘要
为研究缝线对热防护结构拉伸特性的影响,提出一个缝线缝合增强三明治结构(陶瓷-气凝胶-陶瓷)模型。借助有限元软件程序设计语言建模,用多阶次逐步精确分析法确定缝合增强三明治结构内部应力-应变场。首先对支架和不带缝线的试件整体进行有限元分析;然后考虑缝线等详细结构;最后截取子结构进行详细分析。将三明治结构有限元模型应力变化趋势与试验结果分析对比,验证了有限元模型有效性,并且给出有限元解的变化规律。将缝合增强三明治结构与未缝合三明治结构得到的应力-应变曲线进行对比。结果表明,结构底板受单向拉伸且缝线有预应力时,缝合增强三明治结构沿长度方向(x方向)的应力峰值可有效减小(路径1上的最大应力均减小4.6%左右);沿z方向的整体应力大幅度减小(路径3应力平均减小30%左右)。
In order to study the effect of suture on the tensile properties of thermal protection structures, a suture-stitched reinforced sandwich structure(ceramic-aerogel-ceramic) model was proposed. With the help of finite element software programming language modeling, the internal stress-strain field of the stitched reinforced sandwich structure was determined by multi-step stepwise and accurate analysis. Firstly, the finite element analysis of the stent and the experimental piece without suture was carried out;then the detailed structure such as suture was considered;finally, the substructure was taken for detailed analysis. The stress variation trend of the sandwich structure finite element model was compared with the test results of the test piece. The validity of the finite element model was verified and the variation law of the finite element solution was given. The stress-strain curves obtained by the stitching reinforced sandwich structure and the unstitched sandwich structure were compared. The results show that when the structural bottom plate is uniaxially stretched and the suture is prestressed, the stress peak of the suture reinforced sandwich structure along the length direction(x direction) can be effectively reduced(the maximum stress on path 1 is reduced by 4.6%);the stress along the z direction(path 3 is reduced by 30% on average) can be drastically reduced.
作者
林聪
贾德君
李范春
薛涛华
LIN Cong;JIA Dejun;LI Fanchun;XUE Taohua(Ship Architecture and Ocean Engineering College,Dalian Maritime University,Dalian 116026,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2020年第2期432-441,共10页
Acta Materiae Compositae Sinica
基金
国家自然科学基金(5100906)
关键词
三明治结构
缝合
拉伸性能
有限元分析
多阶次计算
sandwich structure
stitching
tensile properties
finite element analysis
multi-order computation
