Experimental investigation of the fluid-structure interaction during deep drawing of fiber metal laminates in the in-situ hybridization process

Abstract. Matrix accumulations, buckling and tearing of fibers and metal sheets are common defects in the deep drawing of fiber metal laminates. The previously developed in-situ hybridization process is a single-step method for manufacturing three-dimensional fiber metal laminates (FML). During the deep drawing of the FML, a low-viscosity thermoplastic matrix is injected into the dry glass fiber fabric layer using a resin transfer molding process. The concurrent forming and matrix injection results in strong fluid-structure interaction, which is not yet fully understood. To gain a better understanding of this interaction and identify possible adjustments to improve the process, an experimental form-filling investigation was conducted. Using a double dome deep drawing geometry, the forming and infiltration behavior were investigated at different drawing depths with full, partial, and no matrix injection. Surface strain measurements of the metal blanks, thickness measurements of the glass fiber-reinforced polymer layer, and optical analyses of the infiltration quality were used to evaluate the results.