Free vibration of the bi-dimensional functionally grated (2D-FG) nanobeamsNgoc Anh Le Thi, Duc Hieu Tran, Ngoc Lan Vu Thi, An Ninh Vu Thi and Dinh Kien NguyenE3S Web Conf., 496 (2024) 02004DOI: https://doi.org/10.1051/e3sconf/202449602004