Hsu Chia-Wen, Hwu Chyanbin
Institute of Aeronautics and Astronautics, National Cheng Kung University, Tainan, Taiwan, ROC.
Proc Math Phys Eng Sci. 2020 Jan;476(2233):20190437. doi: 10.1098/rspa.2019.0437. Epub 2020 Jan 22.
It is known that the stretching and bending deformations will be coupled together for the unsymmetric composite laminates under in-plane force and/or out-of-plane bending moment. Although Green's functions for unsymmetric composite laminates with elliptical elastic inclusions have been obtained by using Stroh-like formalism around 10 years ago, due to the ignoring of inconsistent rigid body movements of matrix and inclusion, the existing solution may lead to displacement discontinuity across the interface between matrix and inclusion. Due to the multi-valued characteristics of complex logarithmic functions appeared in Green's functions, special attention should be made on the proper selection of branch cuts of mapped variables. To solve these problems, in this study, the existing Green's functions are corrected and a simple way to correctly evaluate the mapped complex variable logarithmic functions is suggested. Moreover, to apply the obtained solutions to boundary element method, we also derive the explicit closed-form solution for Green's function of deflection. Since the continuity conditions along the interface have been satisfied in Green's functions, no meshes are required along the interface, which will save a lot of computational time and the results are much more accurate than any other numerical methods.
众所周知,对于非对称复合材料层合板,在面内力和/或面外弯矩作用下,拉伸和弯曲变形会耦合在一起。尽管大约在10年前就已通过类斯托罗形式得到了具有椭圆形弹性夹杂的非对称复合材料层合板的格林函数,但由于忽略了基体和夹杂不一致的刚体运动,现有解可能导致基体与夹杂界面处的位移不连续。由于格林函数中出现复对数函数的多值特性,应特别注意映射变量分支割线的正确选择。为解决这些问题,在本研究中,对现有的格林函数进行了修正,并提出了一种正确评估映射复变量对数函数的简单方法。此外,为将所得解应用于边界元法,我们还推导了挠度格林函数的显式封闭形式解。由于格林函数中已满足沿界面的连续性条件,因此沿界面无需划分网格,这将节省大量计算时间,且结果比任何其他数值方法都更精确。