Understanding process-induced spring-in of L-shaped composite parts using analytical solution

Abstract

This paper aims to understand formation mechanism of the process-induced distortions in the L-shaped composite parts by analytical solutions. To this end, an analytical solution for the total spring-in of L-shaped composite parts is derived by defining the total spring-in as the integrated process-induced distortions in the flange and corner components in combination with shear-lag theory. The new solution, together with previously proposed analytical solution for the corner spring-in of L-shaped parts, not only quantifies the correlation of total spring-in with material and geometrical properties, but also calculates the specific contribution of flange and corner to the total spring-in. The close consistency and trend between analytical predictions and experimental data on the spring-in of L-shaped composites parts show the validity of new analytical solution. Further comparison between numerical simulations and analytical predictions for total spring-in of L-shaped composite parts with various configurations also gives favourable validation for the newly proposed analytical solution.