Fatigue debonding resistance of wrapped composite X-joints

Steel jacket support structures for offshore wind turbine towers made of circular hollow sections (CHS) are becoming a competitive solution compared to monopiles in deeper waters. The current limitation to improving the durability and cost-effectiveness of the CHS structures is the low fatigue endurance of their welded joints. Fatigue-driven...

Ultimate soil resistance of the laterally loaded pile in uniform sand

Piles have been widely used as foundations to resist lateral loads. For the design of a laterally loaded pile, one of the most important inputs is the ultimate soil resistance (p_ult = K_ultDσv^′,whereKult is the ultimate lateral soil resistance coefficient, D is the pile diameter, and σv^′ is the...

Stochastic Modelling of Randomly Oriented Tapes Thermoplastic Composites in Net-Shaped Specimens

Discontinuous tape composites have considerable attention due to their high formability and tailorable structures. Despite their advantages, this discontinuity leads to complex structures and makes it difficult to predict their mechanical properties. On the other hand, they have high orientational and dimensional sensitivity, which causes...

A new virtual fiber modeling approach to predict the kinematic and mechanical behavior of through-thickness fabric compression

We propose a new modeling strategy based on hybrid elements for virtual fiber modeling (also known as the digital element method) to predict both kinematics as well as mechanics of woven fabrics. In virtual fiber modeling, yarns are modeled consisting of a number of discrete fibers. We show that through the development of a modeling strategy...

Sleepers Spacing Analysis in Railway Track Infrastructure

Sleeper spacing has been a taboo subject throughout the railway’s history. Safety concerns related to the structural integrity have been the main causes of not addressing this matter. There are no specific and clear recommendations or guidelines in relation to this matter and the distances do not go more than 0.8 m. In order to go beyond this...

An Integrated Modelling Approach for the Seismic Collapse Assessment of Masonry Towers

Failure of tall slender masonry structures during earthquakes often involves partial collapse of the structure well-above ground level. Consequently, the elastic response of the structure needs to be considered, which often requires modal analysis using finite element models — the generation of which can be labour-intensive and time-consuming...

An Analytical and Numerical Approach for Shear Failure of Pier-Wall Connections in Typical Dutch URM Buildings

Since the 1980s, calcium silicate element masonry has been commonly used in Dutch buildings, and vertical continuous joints have been usually located at the corner of perpendicular walls. Since the shear failure of these joints may significantly reduce the seismic performance of the flanged wall and therefore of the entire building, the...

Concept Design Study of Laterally Loaded Monopiles in Sand

Single large diameter piles, known as monopiles, are, nowadays, the most common foundation type for offshore wind turbines (OWT). Several research initiatives have been focusing on improving the conventional design practice. The PISA (Pile Soil Analysis) joint industry research project resulted in a proposal for a new design methodology for OWT...

Transducer Placement Option of Lamb Wave SHM System for Hotspot Damage Monitoring

In this paper, we investigated transducer placement strategies for detecting cracks in primary aircraft structures using ultrasonic Structural Health Monitoring (SHM). The approach developed is for an expected damage location based on fracture mechanics, for example fatigue crack growth in a high stress location. To assess the performance of the...

Multi-physics computational models of articular cartilage for estimation of its mechanical and physical properties

Recent advances in the realm of computational modeling of complex multiphysics phenomena in articular cartilage enabled efficient and precise determination of articular cartilage properties. However, still accurate quantification of complicated indentation and diffusion processes tying closely with the inhomogeneity of articular cartilage...

Modelling Pile Installation Effects: A Numerical Approach

One of the most traditional methods for supporting structures resting on soft soils is the use of piles. They generally work by transferring the loads to deeper soil layers, which can provide sufficient bearing capacity when mobilised. This type of foundations has been commonly used throughout the world and also in the western part of the...

Local Cooling during Welding: Prediction and Control of Residual Stresses and Buckling Distortion

One of the major problems during welding of thin plate structures is the occurrence of buckling distortion. This type of distortion is caused by the formation of compressive welding stresses; when these stresses exceed a certain critical stress level, the structure will buckle. Most methods for eliminating the welding induced buckling distortion...

Biomechanics of the pelvic floor musculature

The present thesis was motivated by two main goals. The first research goal of the thesis was to understand the complex biomechanical behaviour of the pelvic floor muscles. The second goal was to study the mechanism of the pelvic organ prolapse (genital prolapse). The pelvic floor in humans is a very complex muscular structure. It is largely...