• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Low-velocity impact on composite sandwich plates.
【24h】

Low-velocity impact on composite sandwich plates.

机译：低速冲击复合夹层板。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The response of composite sandwich plates to low-velocity impact is the subject of this research. The objective of the research is to analytically model the response of composite sandwich plates to low-velocity impact. A displacement based, plane stress, finite element code is modified for this purpose. Major new algorithms include 5{dollar}rmsp{lcub}th{rcub}{dollar} order Hermitian interpolation, three-dimensional equilibrium integration for transverse stress calculations, sandwich core modeling as an elastic-plastic foundation, loading by simulated contact with a spherical indentor, adaptive mesh, damage prediction, damage progression via stiffness reduction, and local-global analysis for displacement. An experimental effort is also included in which composite sandwich plates with graphite-epoxy facesheets and Nomex honeycomb core are subjected to low velocity impact (instrumented impactor) and static indentation. Comparison of static and dynamic results indicates limitations for the quasi-static assumptions typically made. Dynamic simulation of the impact event is provided by a one-dimensional, three-degree of freedom model. Classical three-dimensional and cylindrical bending elasticity solutions attributed to Pagano are modified for Hertzian contact and sandwich structures, providing an exact solution against which the finite element analysis is benchmarked. The two-dimensional (plane stress) finite element analysis, when combined with the three-dimensional equations of stress equilibrium predicts the three-dimensional state of stress in an undamaged composite sandwich under contact-type loading. The three-dimensional stresses obtained from the equilibrium equations and the in-plane finite element stresses compare favorably with the elasticity solution. When compared to the experimental data, the finite element analysis shows the ability to model some of the important features of static indentation of composite sandwich structures. In particular, the slope of the load displacement curve (stiffness), including contact, before damage is well represented. Core failure load is predicted by the analysis within ten percent of the experimental value. Delamination patterns predicted by the analysis are similar in shape to the delaminations observed by C-scans from the experiments, but are smaller for the same load.
机译：复合夹层板对低速冲击的响应是本研究的主题。该研究的目的是对复合夹芯板对低速冲击的响应进行分析建模。为此，修改了基于位移的平面应力有限元代码。主要的新算法包括5 {dollar} rmsp {lcub} th {rcub} {dollar}阶Hermitian插值，用于横向应力计算的三维平衡积分，作为弹塑性基础的夹心模型，通过与球形的模拟接触加载压头，自适应网格，损伤预测，通过降低刚度进行的损伤进展以及局部全局位移分析。还包括一个实验性工作，在该工作中，具有石墨-环氧树脂面板和Nomex蜂窝芯的复合夹芯板会受到低速冲击（插入式冲击器）和静态压痕。静态和动态结果的比较表明，通常要对准静态假设进行限制。冲击事件的动态仿真由一维，三自由度模型提供。帕加诺（Pagano）提出的经典三维和圆柱弯曲弹性解决方案针对赫兹接触和夹心结构进行了修改，从而提供了一种精确的解决方案，以此为基准进行了有限元分析。二维（平面应力）有限元分析与应力平衡的三维方程式结合使用时，可以预测在接触型载荷下未损坏的复合材料夹心中的三维应力状态。从平衡方程获得的三维应力和面内有限元应力与弹性解比较好。当与实验数据进行比较时，有限元分析显示了能够对复合夹层结构静态压痕的一些重要特征进行建模的能力。尤其是，可以很好地表示出载荷位移曲线的斜率（刚度），包括损坏之前的接触。通过分析可以预测铁心失效负荷在实验值的百分之十以内。通过分析预测的分层模式在形状上与通过C扫描从实验中观察到的分层类似，但在相同载荷下较小。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号