摘要
与传统的压电材料相比,功能梯度压电材料(functionally graded piezoelectric material,FGPM)具有力学性质(如压电常数、介电常数、弹性模量、密度等)沿某一方向连续变化的特点,从而可以避免应力集中,有效延长所构成元器件的使用寿命。在实际工程中,材料中的界面结构常常含有裂纹、空穴等多种形式的缺陷,在外载荷作用下缺陷附近的区域易发生应力集中甚至断裂。目前,对于功能梯度压电材料断裂问题的研究仅限于单一形式的缺陷,即在材料界面处仅存在空穴或仅存在裂纹,对于复合型缺陷的研究还很少。针对反平面剪切波作用下的含孔边激发界面裂纹缺陷的双相FGPM,提出一种分析其裂尖场动应力集中问题的计算方法。通过采用Green函数法、坐标变换法、裂纹“切割”与“契合”技术构建力学模型,将裂纹问题转化为第一类Fredholm型积分方程的求解,从而得到动应力强度因子(dynamic stress intensity factor,DSIF)的理论表达式。最后,给出数值算例,分析了缺陷的几何形状、入射波特性以及材料的非均匀性等因素对DSIF的影响,结果的正确性则通过与Griffith裂纹模型对比来验证。
Compared with traditional piezoelectric materials,functionally graded piezoelectric material(FGPM) have characteristics of continuous change of mechanical properties(such as,piezoelectric constant,dielectric constant,elastic modulus,density,etc.) along a certain direction,they can avoid stress concentration and effectively prolong the service life of components made with them.In practical engineering,interface structure in materials often contains cracks,cavities and other forms of defects.Under external load,the area near defects is easy to have stress concentration and even fracture.At present,studying fracture problems of functionally graded piezoelectric materials is limited to a single form of defects,i.e.,there are only cavities or cracks on material interfaces,and less studies are focused on composite defects.Here,a calculation method for analyzing dynamic stress concentration in crack tip field of biphasic FGPM with interface crack defects excited by cavity edge under the action of anti-plane shear wave was proposed.By using Green function method,the coordinate transform method and the crack “cutting” and “fit” technique to construct the mechanical model,the crack problem was converted into solving the 1 st kind of Fredholm type integral equation to obtain the theoretical expression of dynamic stress intensity factor(DSIF).Finally,a numerical example was given to analyze effects of defect geometry,incident wave characteristics and material heterogeneity on DSIF.The correctness of the results was verified by comparing themselves with results obtained using Griffith crack model.
作者
安妮
宋天舒
赵明
AN Ni;SONG Tianshu;ZHAO Ming(College of Aerospace and Architecture Engineering,Harbin Engineering University,Harbin 150001,China;School of Civil Engineering and Architecture,Northeast Electric Power University,Jilin 132012,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第7期126-134,共9页
Journal of Vibration and Shock
基金
中国高校科学基金(HEUCFP201846)。
