Investigation on the Initial System Angle of a Torsion Springs using Cad

TL;DR

This paper presents a novel methodology combining CATIA and ABAQUS to accurately determine the initial system angle of tilted torsion springs, addressing a gap in existing industrial software capabilities.

Contribution

A new approach using CAD and finite element analysis to measure the initial tilt angle of torsion springs in their assembled state.

Findings

Method successfully determines initial system angle.

Modeling contact interactions is feasible with connector elements.

Results enable improved spring design and analysis.

Abstract

Helical torsion springs with tangential legs are used for many applications: from simple everyday use systems, like clothes peg, to advanced systems, as sectional doors. Torsion springs are usually exploited with an inner rod as a guide. The required space between the spring and the rod make the spring tilted. Unfortunately, as far as we are aware, no industrial software is able to determine the initial system angle made by the spring in its tilted position. All the torque/angle curves are presented with relative angles. It means that whatever the number of coils considered, the angle is null when the torque is null. For that reason, we have developed a methodology using both CATIA and ABAQUS to determine the system angle at the beginning of the behavior. The model exploits wires designed with CATIA and imported in ABAQUS for the center rod, the torsion spring and the rods of the system to apply the torque. Several options to model contact between the several parts have been investigated. They mostly use connector with an axial property and a stop criterion. The obtained results are very interesting and enable to plan further studies.