Younesian, DavoodAskari, HassanSaadatnia, ZiaYildirim, Ahmet2019-10-272019-10-2720101565-13392191-02941565-13392191-0294https://hdl.handle.net/11454/45261Approximate periodic solutions for a conservative nonlinear oscillator containing x(2(m-n)+1/2n+1) elastic force are analytically obtained in this paper. He's Energy Balance Method (HEBM) and He's Variational Approach (HVA) are adopted as the solution methods. Correlation between the approximate frequencies and periodic solutions with the exact ones are verified and discussed. Two special cases are evaluatedeninfo:eu-repo/semantics/closedAccessHe's Energy Balance MethodHe's Variational Approach FormulationNonlinear OscillationArticle111210271032WOS:000288059700006Q2Q1