Análise de tensão e estabilidade em molas de compressão pelo método dos elementos finitos

Abstract

Compression helical springs, when loaded, undergo transverse shear and torsional stresses. Due to the curvature of the turns, the stresses in the inner regions are amplified. Results for circular and square wire cylindrical springs are known. Similar to columns, helical compression springs can fail due to buckling. Thus, the objective of this work is to carry out, through the finite element method, the determination of the factor that correlates the effects of direct shear and stress concentration due to the curvature of the turns for cylindrical, conical, barrel and hourglass springs; perform stability analyzes related to buckling in cylindrical wire springs of circular and square section and determine the applicability of existing results for conical, barrel and hourglass springs. The analyzes showed results in line with previous studies for square and circular wire cylindrical springs (maximum mean relative deviation of 2.168%). For conical, barrel and circular wire hourglass springs, we were able to conclude that the Wahl factor describes well the state of tension in the entire spring (maximum mean relative deviation of 1.582%). For the conical barrel and hourglass springs with square wire, we obtained results similar to those with circular wire, except for the conical spring, which presented a great divergence between the existing results. This fact was due to the high helix angle. The buckling results show that the square wire improves stability due to its higher polar moment of inertia.