EXPRESSIONS FOR PREDICTING FUNDAMENTAL NATURAL FREQUENCIES OF NON-CYLINDRICAL HELICAL SPRINGS

✍ Scribed by V. YILDIRIM

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 185 KB
• Volume: 252
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.2001.4005

✦ Synopsis

Numerical and analytical studies are performed for the free vibration analysis of non-cylindrical (conical, barrel and hyperboloidal types) helical springs. The sti!ness matrix method is used in the numerical analysis. A total of 12 degrees of freedom (six displacements and six rotations) is described for an element. The exact element sti!ness matrix and the exact concentrated element inertia matrix are used in the formulation. The rotary inertia, the shear and extensional deformation e!ects are considered in the analysis. Comparison of the numerical results with the reported results obtained numerically and experimentally gives satisfactory values. After veri"cation of the numerical frequencies, the non-dimensional fundamental frequencies of "xed}"xed non-cylindrical helical springs with circular section are expressed in a simple formula with a maximum absolute relative error of 5% using those numerical values for the constant helix pitch angles (53, 103, and 153). These expressions restricted to the fundamental frequencies are also veri"ed with ANSYS results.