VARIATIONAL FORMULATIONS OF VIBRATION EQUATIONS OF SINUSOIDAL SHEAR DEFORMABLE  BEAMS AND EIGENFREQUENCY SOLUTIONS BY FINITE SINE TRANSFORM METHOD. NIJOTECH [Internet]. 2024 Sep. 20 [cited 2026 May 1];43(3). Available from: https://nijotech.com/index.php/nijotech/article/view/3701