Free vibration/buckling analyses of noncylindrical initially compressed helical composite springs

ABSTRACT

This article presents the use of the stiffness matrix method based on the first-order shear deformation theory to predict the fundamental natural frequencies and buckling loads of noncylindrical unidirectional composite helical springs subjected to initial static axial force and moment. This theoretical study about such springs with circular/rectangular cross-sections and large pitch angles is performed for the first time in the literature. The validity of the present results is verified by the benchmark studies related with initially compressed isotropic cylindrical springs.

KEYWORDS:

• Buckling
• composites
• complementary functions
• free vibration
• spring
• stiffness matrix
• transfer matrix

Acknowledgments

The authors appreciate the valuable comments from the reviewers.