Luca Di Stasio

• Doctor of Philosophy
• Principal Engineer at Topsoe A/S

We consider crack tip deformations under plane stress conditions of a Neo-Hookean sheet reinforced by Neo-Hookean fibers, whose orientation and elastic properties are described by discrete and continuous spatial distributions. The mechanical behavior of the composite is described in terms of the first and fourth invariant of the right Cauchy-Green...

The growth of fiber/matrix interface cracks (debonds) located on consecutive fibers along the through-the-thickness (vertical) direction is studied in glass fiber-epoxy UD composites. Debonds could appear, along the vertical direction, on the same or on opposite sides of their respective fibers. Determining which configuration is the most energetic...

Models of Representative Volume Elements of cross-ply laminates with different geometric configurations and damage states are studied. Debond growth is characterized by the estimation of the Mode I and Mode II Energy Release Rate using the Virtual Crack Closure Technique. It is found that the presence of the 0 ∘ / 90 ∘ interface and the thickness o...

At the end of the second decade of the XXI century, the transportation industry at large faces several challenges that will shape its evolution in the next decade and beyond. The first such challenge is the increasing public awareness and governmental action on climate change, which are increasing the pressure on the industrial sectors responsible...

The bi-material interface arc crack has been the focus of interest in the composite community, where it is usually referred to as the fiber-matrix interface crack. In this work, we investigate the convergence properties of the Virtual Crack Closure Technique (VCCT) when applied to the evaluation of the Mode I, Mode II and total Energy Release Rate...

Models of Representative Volume Elements (RVEs) of cross-ply laminates with different geometric configurations and damage states are studied. Debond growth is characterized by the estimation of the Mode I and Mode II Energy Release Rate (ERR) using the Virtual Crack Closure Technique (VCCT). It is found that the presence of the 0° /90° interface an...

The effects of crack shielding, finite thickness of the composite and fiber content on fiber/matrix debond growth in thin unidirectional composites are investigated analyzing Representative Volume Elements (RVEs) of different ordered microstructures. Debond growth is characterized by estimation of the Energy Release Rates (ERRs) in Mode I and Mode...

The bi-material interface arc crack has been the focus of interest in the composite community, where it is usually referred to as the fiber-matrix interface crack. In this work, we investigate the convergence properties of the Virtual Crack Closure Technique (VCCT) when applied to the evaluation of the Mode I, Mode II and total Energy Release Rate...

The effects of crack shielding, finite thickness of the composite and fiber content on fiber/matrix debond growth in thin unidirectional composites are investigated analyzing Representative Volume Elements (RVEs) of different ordered microstructures. Debond growth is characterized by estimation of the Energy Release Rates (ERRs) in Mode I and Mode...

In recent years, much work has been devoted to the characterization of so-called thin-ply laminates, in which the central 90° ply can today achieve a thickness of the order of 4-5 fiber diameters thanks to the spread-tow technology [1]. Due to the several beneficial properties observed in this class of composites, designers are currently evaluating...

The adoption of the spread tow technology [1] at the industrial level in recent years has allowed the diffusion in the composite market of a novel type of material, the thin and ultra-thin ply laminates. A number of experimental and theoretical investigations over the years have shown the benefits stemming from the new laminate design. Among these,...

The growth of fiber/matrix interface cracks (debonds) located on consecutive fibers along the through-the-thickness direction is studied in glass fiber-epoxy UD composites. Two different families of Representative Volume Elements (RVEs) are developed: the first implements the classic condition of coupling of the vertical displacements to model a un...

Research on scaling laws of damage in materials and structures has absorbed the attention of the Fracture Mechanics community since the inception of the field itself. The attractiveness of such relationships resides in their simplicity and predictive power, which would allow a more cost-effective design of structures. Building on early works in dim...

The design of the course T7005T-Aerospace Materials is analyzed according to the pedagogical principles of constructive alignment [1, 2]. It is found that a design issue exists, particularly in the section of the course devoted to damage in composite materials. This view is supported by the feedback gathered from students who attended the course in...

LTU’s Learning Management System (a.k.a LMS) Canvas, – should be considered as a core system since the majority of teachers and students at LTU using Canvas to support the learning process. The participant should aim to gain knowledge on designing learning environments in Canvas, based on acquired knowledge from the different topics in the Qualifyi...

The design of the course T7005T-Aerospace Materials is analyzed according to the pedagogical principles of constructive alignment [1, 2]. It is found that a design issue exists, particularly in the section of the course devoted to damage in composite materials. This view is supported by the feedback gathered from students who attended the course in...

A few manufacturers in the world, among them NTPT (USA-CH), Oxeon (SE), Chomarat (FR), Hexcel (USA) and Technomax (JP), offer today ultra-thin fiber reinforced composite plies with thicknesses of around 2-4 times the reinforcement’s diameter. Values of the ratio of thickness to reinforcement diameter as small as those found in thin plies test the...

The Energy Release Rate (ERR) and the contact zone size for a fiber/matrix interface debond are studied for a thin-ply glass fiber/epoxy laminate. The main objective is to analyze the effect on the debonding process of the presence of a traction free specimen surface or an adjacent material, in the form of a stiffer UD ply or by considering it as p...

L’industrie aéronautique du XXIe siècle se trouve à faire face à des sollicitations toujours plus pressantes par la société au sens large qui demande, d’un côté, la réduction drastique de son impact environnemental et, d’autre côté, l’extension de l’accessibilité à ces moyens de transport aux classes démographiques moins aisée. Ces demandes se trad...

Introduit il y a environ 20 ans, la technologie dite en anglais spread tow technology a permis la production au niveau industriel des composites stratifiés avec couches extrêmement minces. Les producteurs de ce type de composite, comme North Thin Ply Technology en Suisse et Oxeon en Suède, sont aujourd’hui capables d’offrir des plis pré-imprégnés a...

Introduced around 20 years ago, the so-called spread tow technology has allowed the production on industrial scale of extremely thin fiber-reinforced prepreg plies. The few manufacturers of this kind of composite material, such as North Thin Ply Technology in Switzerland and Oxeon in Sweden, are nowadays capable of providing prepregs with thickness...

Introduced around 20 years ago, the so-called spread tow technology has allowed the production on the industrial scale of extremely thin fiber-reinforced prepreg plies. The few manufacturers of this kind of composite material, such as North Thin Ply Technology in Switzerland and Oxeon in Sweden, are nowadays capable of providing prepregs with thick...

Introduced around 20 years ago, the so-called spread tow technology has allowed the production on the industrial scale of extremely thin fiber-reinforced prepreg plies. The few manufacturers of this kind of composite material, such as North Thin Ply Technology in Switzerland and Oxeon in Sweden, are nowadays capable of providing prepregs with thick...

Delamination onset and propagation represent one of the most safety-critical failure modes in structures made of FRP laminates. Due to the widespread use of laminated composites in primary and secondary structures, the assessment of fracture behaviour of FRP and the development of reliable analytical and numerical formulations for damage prediction...

The development of accurate models and simulations is becoming increasingly important in fault detection and prevention techniques applied to a wide variety of engineered systems. The recent advances in measurement devices technology has provided the designer an incredible amount of data related to acoustic, thermal and optic behaviour of the mater...