Structural adhesive bonding is being increasingly used for civil engineering applications (externally bonded reinforcement, bonded fasteners, etc ...). Yet, some issues remain regarding the assessment of the durability of such assemblies, particularly with regard to creep. For the case of adhesively bonded joints, creep can be affected by the type of polymer and its behaviour, the stress state and level, the temperature, but also by the interfaces and the thickness of the joint that has a direct influence on its mechanical properties. In this study, in order to take into account those different effects, the Arcan test was used to conduct experimental investigations with dedicated testing resources. The creep behaviour of a chosen adhesive joint was investigated and the influence of several parameters was studied: load level, type of load, and temperature. The adhesive thickness and surface preparation were kept constant. The three characteristic creep stages could be identified. The experimental investigations also enabled us to describe the creep behaviour of the adhesive joint in tension and shear during the first two stages using the Burger creep model.
This article presents experimental measurements of breaking wave impact loads on a vertical cylinder. The focus is on the influence of some of the breaking wave properties on the measured force. These properties are the distance to breaking, $\delta$ , defined as the distance between the breaking location and the front face of the cylinder, and the breaking strength, characterised here by the $\varGamma$ parameter proposed by Derakhti et al. (J. Fluid Mech., 2018, vol. 848, p. R2). The wave characteristics are obtained through numerical simulations of the breaking waves using a fully nonlinear potential flow solver. Seven breaking waves with different breaking strengths have been considered. For each wave, the distance to breaking has been systematically varied and the resulting impact force time-history was measured. It is found that except for the two less intense breaking cases, corresponding to values of $\varGamma$ lower than one, there is a value of $\delta$ for which the magnitude of the impact force is maximum. Small variations of the distance to breaking $\delta$ strongly influence the impact force time-history and its maximum. A linear relationship is observed between the maximum force and the breaking strength $\varGamma$ . For the wave cases with values of $\varGamma$ higher than one, the maximum impact force is observed when the distance to breaking $\delta$ is close to 5 % of the wavelength.
Concern for the structural assessment of ship and offshore structures during operations, including unmanned operations. The focus shall be on methodologies translating monitoring and inspection data into operational and life-cycle management advice, with associated criteria for decision making. This shall include diagnosis and prognosis of structural health, prevention of structural degradation and failures, and structural renewal and reuse. The research and development in passive, latent and active systems including their sensors and actuators shall be addressed. Special attention is to be given to structural digital twin technology and methods including reduced order analysis, inverse modelling, and AI technology application, combined with the use of monitoring systems and inspection data, to provide real-time advice for safe operation during the structural life-cycle.
Calculating directly the inner and outer approximation of the image of a set by a function can be challenging. Then, it is sometimes preferred to compute the image of the boundary of the set instead. However, boundary-based methods are subject to the apparition of fake boundaries in the image set. These fake boundaries add pessimism when characterizing the inner approximation of the image set. This paper then introduces the notion of Box Chains to simplify the detection and the suppression of the fake boundaries. The characterization of the inner and outer approximation of the image set in the case of a function from the unit disk D to R2 will be considered, with two examples.
