Finite Element Simulation of HELICOIL® Inserts

This paper details the possibility of simulating HELICOIL (R) inserts using Finite Element Analysis and contact technology. The main procedure is based on the use of contact elements in the Glue-Cohesive setting, which is usually considered for the simulation of composites. The contact represents the behaviour of an interface, including the HELICOIL (R) insert, the sample threads, and the screw threads. The behaviour of the cohesive contact is determined by a multi-linear curve, and is described by several parameters. Our main goal is to determine the number of parameters and their values to provide a defined accuracy. The sample is made of ABS-M30 material, while the screw is made of steel. The Finite Element Model Updating method is used to determine the parameters from experimental data. The problem regarding the addition of a point (parameter) to a multi-linear curve is solved using the principle of halving intervals. A gradient approach combined with a penalisation method is used to identify the parameters of the interface model. The simulation results are compared with data obtained through Digital Image Correlation measurements.