共查询到19条相似文献,搜索用时 93 毫秒
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弹性圆柱壳冲击扭转屈曲的突变模型 总被引:2,自引:0,他引:2
本文将突变理论用于处理冲击载荷下弹性结构的屈曲问题,文中建立了结构冲击屈曲的突变准则,认为临界阶跃载荷位于所提出突变系统的分叉集之中,并由此对两端固支的弹性圆柱壳扭转屈曲进行了分析,给出了不同初缺陷时的临界阶跃扭矩计算公式,通过对临界静态扭矩的计算,表明临界阶跃扭矩小于临界静态扭矩. 相似文献
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静力预加载结构冲击屈曲的突变模型 总被引:6,自引:0,他引:6
基于突变理论给出静力预加载弹性结构冲击屈曲的准则,并将其用于处理Budian-sky-Hutchinson简单力学模型的冲击屈曲分析和受扭圆柱壳的冲击扭转屈曲分析,给出了临界载荷的求解公式。 相似文献
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对钢质和铜质金属圆柱壳的轴向冲击动力响应进行了实验研究,记录了两种不同材料圆柱壳在大质量低速冲击下的冲击力时程曲线,得到其屈曲模态。采用高速摄像及模拟技术给出了钢质圆柱壳渐进屈曲的全过程,为理解钢质圆柱壳的屈曲机理提供了直观的结果。黄铜质圆柱壳在大质量低速冲击下, 出现整个壳面滿布屈曲波纹的塑性动力屈曲现象,说明高速冲击不是产生塑性动力屈曲的充要条件。像铜这样具有高密度的韧性材料,在大质量低速冲击下,会在轴向产生持续的压缩塑性流作用而出现塑性动力屈曲现象。 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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主要研究受轴向冲击圆柱壳非对称屈曲耗能,从轴向屈曲变形、环向屈曲变形和轴向压
缩变形3个角度进行理论推导. 结果表明: 环向屈曲变形能随屈曲折叠边数增加有减小
趋势, 且占总耗能比例很小,可知圆柱壳受轴向冲击屈曲过程中外力做功主要转变为轴向变形
能,环向屈曲变形消耗外力功很少. 相似文献
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在轴向应力波传播和反射过程中弹性有限长圆柱壳非对称动态屈曲 总被引:2,自引:0,他引:2
本文讨论弹性有限长圆柱壳端部受冲击载荷作用,在轴向应力波传播和反射过程中的非对称动态屈曲问题。通过建立和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轴对称临界载荷高;反之,轴对称临界载荷会比非对称临界载荷低;由于应力波的反射,临界载荷降低,因而更容易发生屈曲,屈曲模态也有其不同特点。 相似文献
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本文研究在轴向冲击作用下,具有初始几何缺陷的圆柱壳的非线性弹性动力屈曲问题。由于冲击过程中作用时间极短,应力波的影响变得相当重要,同时认为圆柱壳经历大挠度变形。分析中不仅考虑圆柱壳的径向惯性力,而且也考虑轴向惯性力和几何非线性的影响。假设圆柱壳中位移和薄膜力可分成轴对称分量和非轴对称分量之和,并引入应力函数表示非轴对称内力,对平衡方程应用伽辽金方法,将导出的和冲击物体的质量对动屈曲性能的影响很大。 相似文献
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In this paper, experimental studies are carried out on the buckling of circular cylindrical thin shells under impact torque. Experiments of impact buckling are made on a Hopkinson torsional bar. The torsional bar gives a step torque on the shells. Through an analysis of the strain-time curve obtained in experiment, the dynamic buckling critical torqueM
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and buckling waves numbern of the shell with different geometric data and some qualitative results are obtained. The buckling behavior of circular cylindrical thin shells under static and impact torque is compared. 相似文献
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A perturbation analysis for the impact torsional buckling of imperfective elastic cylindrical shells subjected to a step torque is given..The imperfection is supposed to be small and has arbitrary form.It is shown that only the imperfection which has the shape of static torsional buckling mode could influence the critical step torque.Finally a formula is presented for the critical step torque. 相似文献
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HanQiang(韩强);MaHongwei(马宏伟);ZhangShanyuan(张善元);YangGuitong(杨桂通);WuJike(武际可)(ReceivedNov.18.1994)THEDYNAMICBUCKLINGPROBLEMCAUS... 相似文献
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Zhang Shanyuan Lei Jianping Zhao Longmao Cheng Guoqiang Lu Guoyun 《Acta Mechanica Solida Sinica》2000,13(2):166-172
This article reports an experimental investigation on the axial impact buckling of thin metallic cylindrical shells fully
filled with water. Low velocity impact tests are carried out by DHR-9401 drop hammer rig. The whole process of dynamic buckling
is simulated using LS-DYNA computer code. The consistency between experimental observation and numerical simulation is quite
satisfactory. The investigation indicates that quite high internal hydrodynamic pressure occurs inside the shell during the
impact process. Under the combined action of the high internal pressure and axial compression plastic buckling occurs easily
in the thin-walled shells and buckling modes take on regular and axisymmetric wrinkles.
This project is supported by the National Natural Science Foundation of China(19672039) and the Shanxi Foundation for Returned
Scholars from Abroad. 相似文献
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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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DYNAMIC BUCKLING OF STATICALLY PRELOADED RING-STIFFENED CYLINDRICAL SHELLS UNDER AXIAL FLUID-SOLID IMPACT LOADING 总被引:1,自引:0,他引:1
The Initial Imperfection Amplified Criterion is applied to investigate the geometric nonlinear dynamic buckling of statically
preloaded ring-stiffened cylindrical shells under axial fluid-solid impact. Taking account of the effects of large deformation
and initial geometric imperfection, the governing equations are obtained by the Galerkin method and solved by the Runge-Kutta
method. The effects of static preloading (uniform external radial pressure) on the buckling features and the load-carrying
ability of ring-stiffened cylindrical shells against axial impact are discussed.
The project is supported by the National Natural Sciences Foundation of China (No. 19802017). 相似文献