Adhesives

Comparison of Polyurethane and Epoxy Adhesive High Strain Rate Performance Using Cohesive Zone Model

It is known that the ballistic performance of ceramic composite personnel armour is highly dependent on the thickness of ceramic and backing material. Recent studies have begun focusing on the effect of adhesive bonding between the ceramic and the backing plate, because failure of the adhesive layer can cause separation between the ceramic and backing. This debonding between substrates causes the ceramic to underperform by shattering early due to an imperfect transmission of the stress wave to the backing material. Given that the adhesive plays such an important role in armour, it is important to better understand the underlying physics.

Characterization of a cohesive zone model for adhesives with *MAT_240 and curve mapping method in LS-OPT

The importance of adhesives in automotive structures exposed to high crash loads has increased over the years. To improve the structural sizing, it is necessary to predict the behavior of bonded joints under dynamic impact and crash loads. Cohesive zone models have proven to be suitable for numerically representing adhesive behavior in Finite-Element simulations. However, the manual determination of the model parameters requires experience with the material model and a corresponding amount of time to derive the various parameters. The present work aims at developing an optimization scheme with LS- OPT for the effective and automated identification of input parameters for the material card *MAT_240 (*COHESIVE_MIXED_MODE_ELASTOPLASTIC_RATE) [1] which is used to represent the behavior of the adhesive layer. The present work focuses on a curve mapping process with LS-OPT.