【作者】 赵鹏成；

【导师】 杨世伟；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2009， 硕士

【摘要】 复合材料夹层结构由于制造工艺和本身材料性能特点,使得其构件在制造和使用的过程中不可避免的带有缺陷和损伤,尤其是面芯结合界面容易发生开胶而造成分层缺陷,导致结构的静载强度减小,疲劳寿命降低。本文采取理论分析与试验相结合的方法对含缺陷蜂窝夹层结构模拟件的屈曲问题、静强度、疲劳寿命和低速冲击试验技术进行了较系统的研究,在以下几个方面取得重要进展和技术突破：运用Von-Karman大挠度应力-应变关系,利用Rayleith-Ritz能量法,建立了含面芯分层缺陷的夹层板计算模型,结合夹层板刚度矩阵推导出子板的临界屈曲载荷计算方程。该方程可预测蜂窝夹层结构在受到压缩时发生屈曲失稳的临界应力,其计算结果与试验结果吻合。采用静压缩试验的方法研究了不同形状缺陷对夹层结构静强度的影响,提出了缺陷宽度是导致结构失效主要原因的观点,建立了缺陷宽度比系数η与静压缩强度的近似表达式。对蜂窝夹层结构的疲劳试验方法进行了研究,根据无缺陷蜂窝夹层结构疲劳试验结果,建立了无缺陷蜂窝夹层结构的疲劳寿命方程。在此基础上,提出利用含缺陷蜂窝夹层结构静强度修正系数ε对无缺陷蜂窝夹层结构的疲劳寿命方程进行修正的假设,建立了含缺陷蜂窝夹层结构疲劳寿命方程的工程方法,该方法得到相关试验的验证。试验研制了一种简单、可靠、重复性好、具备实时数据采集功能的FS冲击试验系统,利用该系统能够较好地再现蜂窝夹层结构在生产和使用中受到低能冲击损伤过程及其产生的各种缺陷,从而为进一步研究低能冲击损伤过程、损伤机理和破坏模式初步建立了一种冲击损伤试验技术。更多还原

【Abstract】 In recent years, the study of sandwich composite materials with debonds is hot. The material characteristic and its machining process make it inevitable for sandwich composite materials to have debonds. As the glued core/face interface is the weak part, the delamination often takes place, which will degrade the static intensity and fatigue life of sandwich composite materials. In order to investigate sandwich mechanicals’capability with different shapes of debonds, a series of examination such as the static compressive test, fatigue life test and impact test were carried out through simulating the delamination in core/face interface in sandwich composite, the following is the results:A calculated model about core/face debonds sandwich composite, which can forecast the critical stress in flexure state, is established by applying Von-Karman theory in huge flexibility relation and Rayleith-Ritz energy method. We found that this model is reliable by comparing the calculated results and the data of tests.By analyzing the results of the static compressive test on honeycomb sandwich with different shapes of debonds, we found that the major reason for the invalidation of sandwich structure is the size of debonds, which are vertical to the direction of load. And modulusηis imported to represent the injure degree.An equation about fatigue life is established based on the results of the fatigue test on honeycomb sandwich composite with debonds. The equation modified by modulesεcan prognosticate the fatigue life of honeycomb sandwich composite with debonds.The destroy form and mechanism is analyzed after the low speed impact test on the honeycomb sandwich composite at different energy level. It can be seen that the impact can destroy the upper panel but not influence the lower panel, and the interface between panels with less angle can afford much stronger impact.更多还原