薄壁球壳压缩变形与失稳过程的实验研究

发布时间：2018-04-10 23:40

本文选题：薄壁球壳 + 静态　；参考：《宁波大学》2011年硕士论文

【摘要】：薄壁球壳作为一种基本结构元件,广泛应用于各种运载工具和压力容器,如航天器和深水工程的压力容器等,因此研究薄壁球壳的屈曲具有重要意义。对薄球壳在局部冲击载荷作用下的研究工作将具有重要的理论和应用价值。随着大家对结构安全的关注,对薄壁球壳力学特性的研究也越来越多。本文针对不锈钢的薄壁球壳进行了静态和动态的压缩实验。通过静态的薄壁球壳压缩实验得到的数据进行分析,结果表明:薄壁球壳在压缩翻转失稳时的临界位移δc与薄壁球壳厚度t的比值δc/t和薄壁球壳半径R与厚度t的比值径厚比R/t相关,随着薄壁球壳特征尺寸径厚比R/t的增大,临界翻转位移δc/t增大。薄壁球壳变形力响应曲线随着径厚比R/t的增大而减小。对两种计算曲线和实验曲线的比较得出:通过对计算曲线和实验曲线比较分析得出弹性计算模型在压缩的初始阶段与实验曲线符合的比较好;刚塑性计算曲线在球壳压平的阶段与实验的曲线差别比较大,随着压缩位移的增大,刚塑性计算曲线和实验曲线吻合的比较好。动态压缩实验是在霍普金森杆上进行,动态数据主要包括动态的位移—时间曲线和力—时间曲线,对两条曲线获得进行了详细的介绍,得到了不同冲击速度下的力—位移曲线,对得到的曲线与静态曲线进行了比较分析,分析表明:在压缩的初始阶段,动态的压缩力要小于静态的压缩力。径厚比R/t相同的薄壁球壳在动态冲击压缩下,半径、厚度越小,所需要的压缩力越小。薄壁球壳在冲击压缩下更容易形成非对称屈曲,随着冲击速度的增加,薄壁球壳失稳形成的多边形的边数有增加的趋势。对动态实验进行了有限元计算,在有限元计算结果与实验得出的结果比较吻合的情况下通过有限元计算得到:薄壁球壳随着冲击速度的增加产生非对称屈曲所需要的压缩位移和压缩力不断增加。
[Abstract]:As a basic structural element, thin-walled spherical shells are widely used in various vehicles and pressure vessels, such as spacecraft and deep-water engineering pressure vessels, so it is of great significance to study the buckling of thin-walled spherical shells.The research of thin spherical shell under local impact load will have important theoretical and practical value.With the attention to structural safety, there are more and more researches on the mechanical properties of thin-walled spherical shells.In this paper, static and dynamic compression experiments are carried out for the thin wall spherical shell of stainless steel.The data obtained from static thin-walled spherical shell compression experiments are analyzed.The critical inversion displacement 未 c / t increases.The deformation force response curve of thin wall spherical shell decreases with the increase of diameter to thickness ratio R / t.The comparison of two kinds of calculation curves and experimental curves shows that the elastic calculation model is in good agreement with the experimental curve in the initial stage of compression by comparing and analyzing the calculated curve and experimental curve;The curve of rigid-plastic calculation is quite different from that of experiment in the stage of spherical shell flattening. With the increase of compression displacement, the curve of rigid-plastic calculation is in good agreement with the experimental curve.The dynamic compression experiment is carried out on the Hopkinson bar. The dynamic data mainly include the dynamic displacement-time curve and the force-time curve. The two curves are introduced in detail, and the force-displacement curves under different impact velocities are obtained.The comparison between the obtained curves and the static curves shows that the dynamic compression force is smaller than the static compression force in the initial stage of compression.The smaller the radius and thickness of thin-walled spherical shells with the same diameter / thickness ratio under dynamic impact compression, the smaller the compression force is required.It is easy to form asymmetric buckling of thin-walled spherical shells under impact compression. With the increase of impact velocity, the number of edges of the polygons formed by the buckling of thin-walled spherical shells increases.The dynamic experiment is calculated by finite element method.When the results of finite element calculation are in good agreement with the experimental results, it is concluded that the compression displacement and compression force of thin wall spherical shells are increasing with the increase of impact velocity.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH49

【参考文献】