Joost van Dam

Joost van Dam obtained his master degree in Materials Science and Engineering at the faculty of ME at Delft University of Technology in 2015. His master thesis focused on the corrosion inhibition effect of basic oxygen furnace slag on different types of galvanized steel. In 2015 he joined the CTE group as a PhD candidate, working on physiochemical bonding and degradation phenomena in composite-to-metal bonded joints for heavily loaded structures at extreme environmental conditions.

Research interests of Joost are: adhesion, corrosion and surface chemistry.

Current Project: Durable composite-to-metal bonded joints for heavily loaded structures at extreme environmental conditions - physiochemical bonding and degradation phenomenaThere is an increasing demand in the offshore and maritime industry for reducing the weight of heavily loaded structures. The combination of high-strength steels and composites, e.g. fibre reinforced polymers (FRP), can significantly increase the strength to-weight ratios for lighter and stronger structures. Within these structures hybrid composite-to-metal joints are in favour.

In the last decades, adhesives are increasingly being used instead of traditional joining methods such as rivets and bolts because of the operational cost and mechanical properties, however the durability of these bonded joints limits the use of adhesives to secondary constructions in marine environments.

In this research the effects of seawater and temperature on the bonded joints between steel and FRP is investigated, in order to gain a better understanding of the degradation phenomena taking place at the adherend/adhesive interface. The objective of the research is to identify the physiochemical variables of the adherends’ surfaces that affect the physiochemical bonding and degradation phenomena between the adherends and the adhesive.

Figure 1 illustrates the transport phenomena for water molecules and hydrated ions through the bonded joint, which can lead to corrosion and de-adhesion, and, ultimately, to unexpected failure. This study will ultimately lead to an improved degradation resistance of metallic/polymer hybrid systems and will predict their long term-performance under in-service environmental and load conditions.

Figure 1: Transport phenomena for water molecules and hydrated ions through the bonded joint

The first step in this study is to identify the physiochemical variables of the adherends’ surface that affect the bonding strength between the adherent and the adhesive. During this, steel and FRP are subjected to different pretreatments to investigate the effect of morphology, surface chemistry and semi-conductor properties of the surface on the adhesion strength.

Summary