Analysis of Spring-in Deformation in L-shaped Profiles Pultruded at Different Pulling Speeds: Mathematical Simulation and Experimental Results

Abstract

Peculiarities of the pultrusion manufacturing process lead to the occurrence of spring-in deformations, whereas their value depends on the pulling speed. In this article experimental and numerical analysis was carried out for glass fiber/vinyl ester resin 75 × 75 × 6 mm L-shaped profiles pultruded at pulling speeds of 200 and 600 mm/min. Spring-in angles of produced profiles were determined on the same day of manufacturing when profiles cooled down to room temperature. Higher pulling speeds provoked increased values of spring-in. 2D numerical model accounting for thermo-chemical and mechanical composite’s behavior during pultrusion was implemented in ABAQUS software. Cure Hardening Instantaneous Linear Elastic (CHILE) constitutive law was used to describe matrix resin Young’s modulus evolution. Since both unidirectional (UD) rovings and fabric material were utilized, effective mechanical properties of UD and fabric layers were calculated in accordance with Self-Consistent Field Micromechanics (SCFM) approach. Spring-in angles determined within experimental and numerical studies were compared and a good correlation was found: the errors were 12.6% and 6% for the pulling speed of 200 and 600 mm/min, respectively.