Implementation and appraisal of stress recovery techniques for embedded finite elements with frictional contact

Due to their ability to analyse the behaviour of slender structures with reasonable accuracy and moderate computational expense, embedded finite elements have attracted widespread interest from the geotechnical engineering community. Related formulations describe the soil-structure interaction behaviour at implicit interaction domains to circumvent expensive surface-to-surface mesh tying problems between the slender structure surfaces and the corresponding solid surfaces. Essentially, this requires the implementation of stress recovery techniques to consider the development of effective normal stresses acting along the shaft, for example, to employ Coulomb-type failure criterions. To this date, reliable information on this research aspect is limited, which decreases the confidence in the results obtained with embedded finite elements. This lack of reliable information has motivated the development of three conceptually different normal stress recovery techniques. These techniques are general in a sense that they can be applied to different types of embedded finite elements, irrespective of their implicit interaction domain geometry. It is found that the presented stress recovery schemes are computationally efficient and capture the numerical benchmark response with high fidelity. Potential lines of research in the context of embedded finite element models are explored throughout this work and may serve as valuable reference in future research.