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轴向冲击圆柱壳非弹性响应 总被引:1,自引:0,他引:1
简要论述承受轴向冲击载荷圆柱壳非弹性动屈曲响应的研究进展。采用Karman-Donnell运动方程研究轴向流固冲击载荷作用下的圆柱壳轴对称弹塑性动屈曲问题。本构关系采用增量理论,借助增量数值方法求解动力方程组。研究不同边界条件对屈曲的影响,以及径向外压力在不同边界条件下对屈曲的影响。 相似文献
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充满液体的封闭圆柱壳受轴压时屈曲过程的实验研究 总被引:1,自引:1,他引:1
报导了对充满水的金属圆柱薄壳在轴向压缩时屈曲性能的实验结果。实验观察表明,充满液体的金属圆柱壳在轴压作用下的屈曲模态呈轴对称型,液体的内压与外部轴压随轴向缩短的变化趋势大致相同。由于壳内液体的存在,同内空的圆柱壳相比只是临界载荷略有提高,屈曲后承载能力并无显著降低,且对初始几何缺陷表现得远不象内空柱壳那样敏感。 相似文献
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讨论弹性圆柱壳端部受冲击载荷作用,在应力波传播过程中的非对称屈曲问题。通过求解扰动方程得到了动态屈曲的分叉条件、临界载荷和屈曲模态。数值结果表明,当壳壁厚不很薄时,轴对称屈曲临界载荷比非对称临界载荷高;反之,轴对称临界载荷会比非对称临界载荷低。不同的冲击载荷,屈曲模态也将不同。 相似文献
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水下爆炸载荷作用下环肋加筋圆柱壳结构的弹塑性动力屈曲 总被引:2,自引:0,他引:2
为研究水下爆炸载荷作用下潜艇结构的动力屈曲现象,以潜艇耐压结构的简化模型环肋加筋圆
柱壳结构为研究对象,建立流固耦合有限元分析模型,应用瞬态有限元分析程序MSC.Dytran对该结构在水
下爆炸冲击载荷作用下的弹塑性动力屈曲行为进行研究,基于Budiansky-Roth准则和Southwell方法确定环
肋加筋圆柱壳结构的临界屈曲载荷,讨论结构动力屈曲的影响因素如载荷强度、网格密度、径厚比、长径比、加
筋截面间距、加筋尺寸等对环肋加筋圆柱壳结构动屈曲模态和临界屈曲载荷的影响。结果表明:采用建立的
流固耦合有限元分析模型,应用动力瞬态有限元软件MSC.Dytran可以对加筋圆柱壳结构的动力屈曲行为进
行模拟,模型网格尺寸大小、结构几何参数对结构的动力屈曲临界载荷都有一定的影响,其中加筋圆柱壳结构
的径厚比对结构的动力屈曲临界载荷影响最为显著。 相似文献
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Elasto-plastic buckling of orthotropic laminated plates, which include interfacial damage, is analyzed in detail. Firstly,
a novel mixed hardening yield criterion, as an improvement of Hill’s counterpart, is proposed for the orthotropic materials
on the basis of the plastic theory. And differing from Hill’s theory, the present yield criterion is related to the spherical
tensor of stress. Then, the incremental elasto-plastic constitutive relations of the mixed hardening orthotropic materials
are presented. Secondly, the incremental static equilibrium equations for laminated plates including interfacial damage are
established based on Von-Karman type theory and the principle of minimum potential energy. Finally, the elasto-plastic buckling
of laminated plates are solved by adopting the Galerkin method and iteration scheme. The numerical results show that buckling
of the plate occurs easier due to the existence of interfacial damage, and the critical load trends to constant when the interfacial
damage approaches a certain degree. Also, the effect of anisotropy on buckling is obvious and the analysis of elasto-plastic
buckling is necessary. 相似文献
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Based on the elasto-plastic theory, considering the effect of spherical stress tensor on the elasto-plastic deformation and using the slicing treatment to deal with the plasticity of functionally graded coatings, the elasto-plastic increment constitutive equations of the sandwich plates with functionally graded metal-metal face sheets can be derived. Applying the weak bonded theory to the interfacial constitutive relation and taking into account the geometric nonlinearity, the nonlinear increment differential equilibrium equations of the sandwich plates with functionally graded metal-metal face sheets are obtained by the minimum potential energy principle. The finite difference method and the iterative method are used to obtain the post-buckling path. When the effect of geometrical nonlinearity of the plate is ignored, the elasto-plastic critical buckling load of the sandwich plates with functionally graded metal-metal face sheets can be solved by the Galerkin method and the iterative method. In the numerical examples, the effects of the interface damages, the induced load ratio, the functionally graded index, and the geometry parameters on the elasto-plastic post-buckling path and the elasto-plastic critical buckling load are investigated. 相似文献
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基于弹塑性力学和损伤理论,建立了一个与应力球张量有关的正交各向异性材料的混合硬化屈服准则,该准则无量纲化后与各向同性材料的Mises准则同构,在此基础上,进而建立了混合硬化正交各向异性材料的增量型弹塑性损伤本构方程,并以具局部损伤的正交各向异性矩形薄板为例,采用Galerkin法和迭代法,对其弹塑性屈曲问题进行了分析,讨论了局部损伤对正交各向异性矩形薄板弹塑性屈曲临界应力的影响. 相似文献
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圆柱形薄壳冲击扭转屈曲的实验研究 总被引:1,自引:0,他引:1
本文对受冲击扭矩作用下的圆柱形簿壳扭转屈曲进行了实验研究,利用Hopkinson扭杆使圆柱受阶跃扭矩作用,分析所得到的应变-时间曲线,得到了不同几何参数的圆柱壳的冲击临界扭矩Mder和屈曲波数n及几条定性结论,同时找出了圆柱壳静力扭转屈曲行为和冲击扭转屈曲行为之间的异同。 相似文献
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粘塑性流体的界面滑移对润滑性能的影响研究 总被引:3,自引:0,他引:3
首先指出经典润滑理论中的边界无滑移条件已不再适用于具有极限剪应力的粘塑性流体润滑.而后,通过确定最大剪应力位置和加入剪应力边界条件,建立了界面滑移后的润滑方程.在联立求解不同区域的润滑方程基础上,对界面滑移的开始位置及扩展方式进行了分析.最后,讨论了不同膜厚比下滑移对润滑性能的影响. 相似文献
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结构流—固冲击屈曲研究进展 总被引:8,自引:0,他引:8
本文回顾和综述结构在流-固冲击载荷作用下的动力屈曲问题的研究工作,重点分析、评述流-固冲击屈曲的特征、实验资料及已取得的成果,并展望了该领域今后的研究 相似文献
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ON THE ORIENTATION OF BUCKLING DIRECTION OF ANISOTROPIC ELASTIC PLATE UNDER UNIAXIAL COMPRESSION 总被引:1,自引:0,他引:1
Zhang Yitong 《Acta Mechanica Solida Sinica》2001,14(2):130-137
The theory of small deformation superimposed on a large deformation of an elastic solid is used to investigate the buckling
of anisotropic elastic plate under uniaxial compression. The buckling direction (the direction of buckling wave) is generally
not aligned with the compression direction. The equation for determining the buckling direction is obtained. It is found that
the out-of-plane buckling of anisotropic elastic plate is possible and both buckling conditions for flexural and extensional
modes are presented.
As a specific case of buckling of anisotropic elastic plate, the buckling of an orthotropic elastic plate subjected to a compression
in a direction that forms an arbitrary angle with an elastic principal axis of the materials is analyzed. It is found that
the buckling direction depends on the angle between the compression direction and the principal axis of the materials, the
critical compressive force and plate-thickness parameters. In the case that the compression direction is aligned with the
principal axis of the materials, the buckling direction will be aligned with the compression one irrespective of critical
compressive force and plate-thickness.
Project supported by the National Natural Science Foundation of China (No. 19772032). 相似文献
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基于弹塑性力学和损伤理论,建立了一个与应力球张量有关的具损伤正交各向异性材料的混合硬化屈服准则,该准则无量纲化后与各向同性材料的Mises准则同构,在此基础上,建立了正交各向异性材料的增量型和全量型弹塑性损伤本构方程,并以具确定弱区域正交各向异性矩形薄板为例,根据屈曲时的能量准则和全量理论,以等效塑性应变为内变量,对其弹塑性屈曲问题进行了分析,讨论了几何参数和弱区域对正交各向异性薄板弹塑性屈曲临界应力的影响. 相似文献
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脱层梁屈曲的高阶剪切理论 总被引:5,自引:0,他引:5
脱层的存在将会大大降低层合结构的屈曲载荷。该文将含任意位置脱层的两端固支梁分成多段子层,用厚度的三次多项式模拟脱层梁屈曲时子层的轴向位移,利用变分原理和欧拉方程导出了脱层梁的屈曲方程和定解条件,并用状态空间方法进行求解。通过与一阶剪切理论和经典理论的比较,指出了它们各自的适用范围;考虑了脱层梁三种不同的屈曲模态。分析了脱层长度、深度、位置和材料的铺层方向对脱层梁屈曲载荷的影响;最后给出了多处简单脱层的屈曲分析。 相似文献