Publications

The Delay and Sum (DAS) method is a well-known damage imaging technique in sparse array guided wave imaging. However, the DAS method requires prior knowledge on the stable baseline state, which makes it ineffective under different operational or environmental conditions, e.g. temperature and moisture, and altered experimental settings, e.g. degraded bonding quality of sensors. This paper proposes a Nonlinear Delay and Sum (NL-DAS) method which ...

This paper presents a novel Finite Element (FE) simulation approach to examine the mode I fracture of thick adhesive joints used particularly in the trailing edge of the wind turbine blades. The approach involved FE models of the DCB specimens focusing on aspects overlooked in the existing literature. There has been limited investigation on residual stresses caused by thermal mismatch between composites and adhesives. Similarly, the impact of ...

Wind turbine blades are manufactured by molding them in two halves and joining them using thick adhesive joints. The failure of these adhesive joints, particularly in the trailing edge of the blades, compromises the structural integrity of the wind turbine. Therefore, comprehending the mechanisms of failure in adhesive joints is critical to designing wind turbine blades efficiently. For this purpose, the present study proposes a novel approach ...

This paper studies thermomechanical coupling during room-temperature tensile testing of polyamide-6 (PA6) and short glass fibre/PA6 (50 wt%). The tests were performed for different dominant angles of the short fibres (0°, 45°, 90°), moisture contents (dry, 50%RH), and strain rates (10 −4 , 10 −2 , 10 −1 s −1). Digital image correlation (DIC) was coupled with infrared thermography. The contribution of the local strains, strain rates and ...

In short fibre composites, debonding cracks usually initiate from fibre tips and their growth is governed by the properties of the fibre/matrix interface. These properties are ideally acquired from a model test similar to the real composite, while excluding the effects of fibre fractures and the induced debonding interactions. Therefore, in this study, debonding growth was examined in detail, using novel single short fibre specimens, which were ...

The significant variability in the high-cycle fatigue of additive manufactured (AM) Ti-6Al-4V has impeded its confident application in fatigue-critical components. One of the major factors responsible for the fatigue-life variability is the presence of intrinsic defects left by the additive manufacturing process. The goal of this work is to investigate the fatigue-life variability as the function of (i) the locations of the defects, viz., ...

This research presents a numerical multi-scale approach that efficiently addresses the inelastic and timedependent mechanical response of short fiber reinforced polymers (SFRPs) under monotonic loading conditions by linking the mechanical analysis from microscale analysis to a continuum model. To do so, first, the mechanical performance of a recently suggested unit cell, considering the intrinsic mechanical characteristics of both fiber and ...

This paper studies thermomechanical coupling during room-temperature tensile testing of polyamide-6 (PA6) and 50 wt% short glass fibre/PA6. The tests were performed for different fibre angles (0°, 45°, 90°), moisture contents (dry, 50%RH), and strain rates (10^(-4), 10^(-2), 10^(-1) s^(-1)). Digital image correlation (DIC) was coupled with infrared thermography. The contribution of the local strains, strain rates and temperatures to the global ...

Fibre Reinforced Plastics (FRPs) do not have currently an environmentally friendly and energy-efficient end-of-life scheme. As a result, the demand for sustainable composite materials is increasing leading to the need for new reprocessable FRPs. Vitrimers are a novel epoxy-based polymer that thanks to their Covalent Adaptable Network (CAN), couple the reprocessing properties of thermoplastics with the performance of thermosets. In this work, ...