TY - JOUR T1 - Direct normal form analysis of oscillators with different combinations of geometric nonlinear stiffness terms JO - Journal of Applied and Computational Mechanics PY - 2021/06/01 AU - Nasir A AU - Sims N AU - Wagg D ED - DO - DOI: 10.22055/JACM.2021.34016.2324 PB - Shahid Chamran University of Ahvaz VL - 7 IS - Special Issue SP - 1167 EP - 1182 Y2 - 2025/07/11 ER -