Fabrizio Moroni

Università di Parma | UNIPR · Department of Engineering and Architecture

Hygienic design is an engineering approach focusing on the development of food processing systems and equipment in compliance with hygienic requirements such as food contact compatibility, easy cleaning, and special maintenance needs. Currently, hygienic design knowledge is fragmented and a method to list and collect this knowledge in a structured...

This work is aimed at exploring the feasibility of ultrasonic welding (USW) of a composite laminate made of polycarbonate reinforced with continuous glass fibers, with and without the addition of an energy director (ED) in the form of a neat polycarbonate wire. Welding has been done by varying one factor at a time in order to highlight the dependen...

The demand for ever-lighter structures raises the interest in bonding as a joining method, especially for materials that are difficult to join with traditional welding and bolting techniques. Structural adhesives, however, are susceptible to defects, but can be toughened in several ways: by changing their chemical composition or by adding fillers,...

Nanosecond pulsed laser texturing has been performed as surface preparation for adhesive-bonded polyamide 66 (PA 66) joints. A Design-of-Experiments approach was firstly applied for optimization of laser parameters in terms of static joint strength, after which the fatigue strength of the best performing joints was determined. Quasi static and fati...

The present work reports on the preparation and subsequent mechanical, morphological and thermal characterization of composites based on poly(butylene adipate terephthalate) (PBAT), reinforced with micro‐particles of inorganic bioabsorbable calcium‐phosphate glass (CPG) at different contents up to 40 wt%. The PBAT‐CPG composites were prepared by so...

The peak stress method (PSM) allows a rapid application of the notch stress intensity factor (NSIF) approach to the fatigue life assessment of welded structures, by employing the linear elastic peak stresses evaluated by FE analyses with coarse meshes. Because of the widespread adoption of 3D modeling of large and complex structures in the industry...

Traditional assembly processes such as screw fastening and riveting are increasingly being replaced by new processes such as adhesive bonding. Life cycle performance including fatigue and durability are critical, for which surface activation techniques are often used with the aim of improving both mechanical and life cycle performance. Within this...

In order to optimize the stiffness/weight ratio and to reduce the manufacturing time, Additive Manufacturing (AM) components are built up by a solid skin and a partially filled core. The filled/total volume ratio is called infill ratio and it is one of the printing parameters to be selected. Since the infill ratio affects the global as well as the...

The purpose of this work is to compare the co-bonding vs. cold-bonding route on the adhesive joint performance of a CFRP (Carbon Fiber Reinforced Polymer) laminate–aluminum connection. In particular, the overlap shear, tensile strength and Mode I and Mode II fracture toughness will be evaluated. The adhesives for co-bonding and cold-bonding are, re...

This work deals with the experimental validation of the proposed specimens geometries which design process through Finite Element Method was presented during AIAS 2019 and published afterwards [1]. In particular, non-conventional miniaturized specimen geometry compliant to ASTM E8 and ISO 6892, specifically developed to work with MaCh3D [2], an inn...

Adhesive bonding can disclose the possibility to additively manufacture (AM) smaller, highly optimized objects to be bonded in post-production into/onto larger components. However, the infill shape and percentage can influence the fracture toughness of a bonded joint as it emerges from the literature Since the choice of the infill yields also a sig...

The low quality of adhesion performance on polymeric surfaces has forced the development of specific pretreatments able to toughen the interface between substrate and adhesive. Among these methods, atmospheric pressure plasma treatment (APPT) appears particularly suitable for its environmental compatibility and its effectiveness in altering the che...

This work aims to explore innovative joining processes for additively manufactured components, and, in particular, to assess the feasibility of hybrid weld-bonded joints by comparing their performance with the baseline bonded and welded joint configurations. The novelty of the proposed solution lies in the fact that welding is achieved using a 3D p...

This work explores the influence of Additive Manufacturing (AM) parameters on the Mode I fracture toughness of polymer bonded joints. The motivation is that realizing AM parts to be later assembled can be convenient from the manufacturing standpoint and adhesive bonding avoids distortion and material modification due to heat while welding or the us...

This work emphasizes the critical need of surface preparation to improve the performance of adhesively bonded 3D printed Acrylonitrile Butadiene Styrene (ABS) adherends obtained using Fused Filament Fabrication (FFF). In particular, mechanical abrasion and two different plasma pre-treatments, i.e., Atmospheric Pressure Plasma (APP) and Low-Pressure...

The use of engineering polymers for mechanical applications has seen increasing uptake due to properties such as low density, flexibility, ease of manufacturing and cost effectiveness. Despite these advantages, joining and assembly methods for these types of materials is still an open issue. Traditional assembly processes such as screw fastening an...

Food packaging industry requires machines able to perform different tasks and carry out several functions. Machine modularization allows to feed customer’s needs creating a set of equipment with different features and technology. Module derivation is particularly important at the conceptual phase where main decisions are taken and where the degree...

In order to prevent the generation of a potential weakness at the substrate/adhesive interface of adhesively bonded joints, many methods were developed during the decades to pre-treat the substrates surfaces before the deposition of the adhesive. Experimental tests were carried out to simulate the real environmental conditions in which the joints h...

Nanosecond pulsed laser texturing was performed on pigmented polyethylene (PE) specimens with a 1064 nm fiber laser with the aim of improving adhesive-bonded joint strength. A Design-of-Experiments (DoE) was employed to optimize process parameters and determine the effects of average laser power, scanning velocity and hatch spacing on the resulting...

The capability of the Atmospheric Pressure Plasma Treatment (APPT) to increase the shear strength of adhesively bonded Single Lap Joints (SLJ) realized with polymeric adherends was investigated, by exploring the different response obtainable by changing the surface-to-nozzle distance and the treatment speed and by considering an industrial applicat...

The work illustrates how building parameters of the Additive Manufacturing process Fused Filament Fabrication can affect not only the mechanical properties but also the surface wettability and morphology. Wettability and morphology are relevant factors in bonded joints performance. Advantages of polymeric additive manufacturing are to allow a redes...

The effect provided by the state of the surface on the quality of the adhesion, as well as the sensitivity of the position of the locus of failure to the surface morphology, is known to be one of the most crucial issue to be addressed when evaluating the capability of the bonded joint to withstand any mechanical stress. Therefore, the need for the...

Structural adhesives are widely used in industrial applications dealing with the problem of assembly and bonding. Despite the several advantages brought by this technique, one of the main issue is represented by the need of the surface to be mechanically and/or chemically treated with the aim to make it suitable for the adhesive deposition. Previou...

A reliable screening and non invasive method based on the use of microextraction by packed sorbent coupled with desorption electrospray ionization-high resolution mass spectrometry was developed and validated for the detection of new psychoactive substances in oral fluid. The role of different sample substrates in enhancing signal intensity and sta...

The cohesive zone model (CZM) has found wide acceptance as a tool for the simulation of delamination in composites and debonding in bonded joints and various implementations of the cohesive zone model dedicated to fatigue problems have been proposed in the past decade. In previous works, the authors have developed a model based on cohesive zone to...

The paper proposes a design method for the configuration of customized workplaces supported by the use of VR tool. The method allows to consider end-users anthropological features and configuration aspects related to the workplace (e.g. equipment). The adoption of VR technology allows supporting the configuration process, engaging end-users in the...

In this study the fracture behavior of different cast iron microstructures subjected to tensile loading under different triaxialities is simulated by a finite element, 3-D Reference Volume Element approach. Three ferritic/pearlitic heterogeneous matrixes are considered which are representative of the class material grades for strength and ductility...

The purpose of this work is to evaluate the influence of co-lamination vs. co-bonding on the failure behavior, and namely the fracture toughness, of carbon fibre reinforced (CFR) composite laminate joints in order to assess comparatively their performance. Since the strength of the laminate and ply texture are parameters affecting the strength of t...

Recent trends in car body manufacturing indicate that the use of a consistent mix of lightweight materials in conjunction with adhesive bonding, not only allows substantial weight reduction, but can also drive down costs and potentially enables more intelligent designs. Yet, presently, it is highly desirable that the introduction of structural adhe...

Carbon-Fiber Reinforced Polymer (CFRP) parts are joined mainly using adhesive bonding because, differently from fastening, additional parts (hence weight saving) and through holes (that are always detrimental for the strength due to the possibility of developing damage into the composite) are not necessary. Additionally, it allows for large connect...

Material testing is a fundamental activity for the characterization of materials mechanical properties and for the certification of product quality. With concepts such as Smart Factories and Industry 4.0 coming to the fore, testing and measurement is moving away from laboratories and closer to the production floor: MaCh 3D is a miniaturized tensile...

Hybrid joints consist of mechanical connections in which both a traditional mechanical joint (i.e. riveting, clinching, welding) and adhesive bonding coexist in order to obtain a better performance if compared with simple bonded or mechanically connected joints. Several literature works demonstrates how hybrid joining allows to improve strength, st...

The state of the surface plays a crucial role in defining the mechanical properties of bonded joints, in particular, the chemical state of the adherend surface and its structural morphology have been proved to be the main elements of the bonding process. The structural morphology of the surface strictly depends from its topological features, like r...

Il material testing è un'attività fondamentale per la caratterizzazione delle proprietà meccaniche dei materiali e per la certificazione della qualità dei prodotti. Con l'avvento dell'Industria 4.0 e delle Smart Factories l'attività di qualifica materiali sta spostandosi dai laboratori alle linee di produzione: MaCh 3D è una macchina di prova minia...

This paper tries to relate the laser treatment process parameters to the morphological properties of laser-treated aluminum alloy surfaces and the adhesive joint fracture load in butt joint configuration to describe their pivotal role as surface roughness design parameters. In these contexts, the role of the individual process parameter and energy...

The peak stress method (PSM) is an engineering, finite element (FE)‐oriented method to rapidly estimate the notch stress intensity factors by using the singular linear elastic peak stresses calculated from coarse FE analyses. The average element size adopted to generate the mesh pattern can be chosen arbitrarily within a given range. Originally, th...

Surface texturing produced by laser ablation is an efficient and effective technology for treating substrates to improve adhesive bond strength. In the literature, its effect has been extensively studied for different adherends materials, adhesives and laser sources. Laser ablation produces both morphological and chemical modifications of the surfa...

Adhesive bonding is currently employed by automotive manufacturers to complement (or replace) welding in joining dissimilar materials. In order to reduce the impact on the existing manufacturing infrastructures, structural adhesives are deployed in the body shop but hardening is accomplished in the paint cure oven. Various adhesive formulations hav...

Adhesive bonding is the elective joining system between Carbon-Fiber Reinforced Polymer (CFRP) parts because, with respect to fastening, it allows a large connection area, no additional parts (hence weight saving) and no need to drill holes into the composite, that is always detrimental for the strength due to the possibility of developing damage....

The influence of ns-pulsed laser ablation on the adhesive strength of bonded joints was studied under conservative conditions by tensile stress tests on cylindrical specimens of aluminium alloy. Surface textures were produced by hatching the cross section with concentric grooves and varying the average laser power at fixed repetition rate, the scan...

Recent literature works focused on the analysis of laser irradiation on the strength of adhesive joints under quasi-static loading conditions. It has been demonstrated that laser surface preparation allows to remove impurity and weak boundary layers from the mating substrates and, depending on the energy density, it is also able to modify surface m...

In previous works, the authors showed that the interleaving of an electrospun nylon nanofibrous mat at the interface between adjacent plies of a composite laminate increases the delamination strength. In particular, the nanomat acts a net-like reinforcing web, enabling a ply-to-ply bridging effect. This reinforcing property of the nanomats can be p...

Composite, stiffened integral structures are becoming of increasing interest in the fields of aeronautics, automotive, nautical, and wind energy, where they are present in core structural applications. A numerical method able to reproduce the complex fatigue mechanisms in a stiffened panel is therefore attractive to improve their performances.In th...

The cohesive zone model (CZM) has found a wide acceptance as a tool for the simulation of debonding in adhesive joints. Recently, fatigue-devoted implementations of CZM have been proposed. In earlier works, the authors have developed a model of the cohesive zone able to correctly simulate the propagation of fatigue of two-dimensional (2D) defects i...

This work simulates numerically Double Cantilever Beam and End Notched Flexure experiments on Carbon Fibre Epoxy Resin specimens that have been performed by some of the authors in a previous work. Specimens have been nanomodified by interleaving plies with a layer of electrospun nanofibres in the delaminated interface. Eight different configuration...

The cohesive zone model (CZM) has found a wide acceptance as a tool for the simulation of delamination in composites and debonding in bonded joints. Recently, fatigue-devoted implementations of CZM have been proposed. In earlier works, the authors have developed a model of the cohesive zone able to correctly simulate the propagation of fatigue defe...

Purpose – In this work, the cohesive zone model (CZM) developed by some of the authors to simulate the propagation of fatigue defects in two dimensions is extended in order to simulate the propagation of defects in 3D. The paper aims to discuss this issue. Design/methodology/approach – The procedure has been implemented in the finite element (FE)...

Adhesively bonded metallic and/or composite material structures are present as principal structural elements in several fields, such as aeronautics, automotive, nautical, and wind energy. A numerical method able to reproduce three-dimensional fatigue debonding and, in the case of composites, delamination evolution in bonded structures is therefore...

Adhesively bonded metallic and/or composite material structures are present as principal structural elements in several fields, such as aeronautics, automotive, nautical and wind energy. A numerical method able to reproduce three-dimensionally the fatigue debonding/delamination evolution in bonded structures is therefore necessary to improve their...

The effect of Nylon 6,6 electrospun nanofibers interleaved in composite laminate material is simulated numerically to investigate the differences in the fracture strength between a nanomodified laminate interface and the corresponding non-modified material. DCB and ENF mechanical test results from a previous work of some of the authors are used as...

The cohesive zone model has been widely used for the description of quasi-static crack growth of interfaces and recently evolutions have been proposed in order to account for fatigue phenomena. In this work the cohesive zone model previously developed by the authors to simulate fatigue crack growth at interfaces in 2D geometries is extended to 3D c...

In this work a cohesive zone model is developed to simulate fatigue crack propagation along bonded interfaces. The model is implemented by means of the USDFLD subroutine in the commercial software Abaqus. In particular, the crack growth increment is translated into a damage increment per cycle in the cohesive elements ahead of the crack tip. The co...

The present research is part of the HY-LAP (HYbrid LAP-joints) project carried out at the Dept. of Mechanical Engineering of Politecnico di Milano in collaboration with the MUSP laboratory of Piacenza and the University of Parma. In particular, the present study deals with the fatigue behavior of hybrid lap-joints (obtained by USMW plus adhesive bo...

The chapter deals with the finite element simulation of fatigue crack growth problems in adhesively bonded joints using a modified cohesive zone model. The model developed in this work is initially presented in the case of pure mode I propagation for two-dimensional models. Then, the extension of the model to mixed mode I/II loading, using four dif...

This work deals with the simulation of the fatigue crack growth (FCG) in bonded joints. In particular a cohesive damage model is implemented in the commercial software Abaqus, in order to take into account for the damage produced by fatigue loading. The crack growth rate is evaluated with different Paris-like power laws expressed in terms of strain...

A model to predict fatigue crack growth in bonded joints under mixed mode I/II conditions is developed in this work. The model is implemented in the finite element software ABAQUS using the related USDFLD subroutine. The present model is based on the cohesive zone (CZ) concept, where damage develops according to the value of the opening/sliding at...

The idea of “hybrid joints” arises from the need of joining together materials, producing a tough, stiff and lightweight joint. The core concept is: use two different joining techniques, with the aim to increase the strength and gather the advantages of each technique, reducing the drawbacks. In this work hybrid joints consist in joints produced wi...

The idea of “hybrid joints” arises from the need of joining together materials, producing a tough, stiff and lightweight joint. The core concept is: use two different joining techniques, with the aim to increase the strength and gather the advantages of each technique, reducing the drawbacks. This chapter is devoted to clinch–adhesive (also called...

In general hybrid bonding allows to match together the properties of two different joining techniques, with the aim to obtain a joint with a better set of properties (that could involve strength, energy absorption at failure, cost, etc.) with respect to the simple joints. In the literature, several works dealing with the evaluation of the strength...

Hybrid joints in this article are simultaneous use of two different joining techniques, one of them being adhesive bonding. They, in principle, bring together the advantages of adhesive bonding and traditional joining techniques such as spot welding, riveting or clinching concerning static and fatigue strength, stiffness and energy absorption. Ther...

Results of fatigue tests on adhesive lap joints of thick (9.9 mm) composite laminates are presented and discussed. Specimens of different overlap length (from 25 to 110 mm), different shape, (with and without taper), and different materials (composite on composite, composite on steel) were fatigue tested and distinct fatigue curves were obtained in...

A procedure to predict fatigue crack growth in bonded joints is developed in this work within the framework of cohesive zone modelling and finite element analysis. The idea is to link the fatigue damage rate in the cohesive elements to the macroscopic crack growth rate through a damage homogenisation criterion. In this way, the experimental crack g...

This work deals with the simulation of the fracture behavior of ultrasonic weld bonded joints for aluminum adherends using the cohesive zone model. The parameters of the model are tuned for comparison with experimental tests of simple bonded and simple ultrasonic welded joints. Later on, these parameters are used for the simulation of hybrid joints...

The work deals with the evaluation of the strength and the simulation of the mechanical behaviour of structural hybrid joints. In particular it is addressed to the transportation vehicle construction field, and therefore only suitable technique for this field are taken into account. In the first chapter an overview of the most relevant joining tech...

A fracture mechanics-based model for fatigue failure prediction of adhesive joints has been applied in this work. The model is based on the integration of the kinetic law of evolution of defects originated at stress concentrations within the joint. Final failure can be either brittle (fracture toughness-driven) or ductile (tensile/shear strength-dr...

Hybrid joints allow to bring together the advantages of bonded joints (i.e. lightweight design, cost reduction and higher energy absorption in case of impact loading) with the confidence, the high specific strength and well know production process of traditional mechanical joining technologies like welding, riveting and clinching. In this way, high...

The aim of this work was to simulate the failure behaviour of clinch-bonded (CB) and rivet-bonded (RB) joints using the finite element method (FEM). The Gurson–Tvergaard–Needleman (GTN) model and a ductile damage (DD) model were used as possible alternatives to simulate damage and failure of the rivet and plates, while a cohesive zone (CZ) model wa...

Le giunzioni incollate guadagnano sempre più mercato, nel campo delle costruzioni in genere, dove è necessario un alleggerimento delle strutture. Nel caso di geometrie di giunto semplici il dimensionamento avviene attraverso relazioni analitiche che restituiscono il valore massimo delle tensioni, il quale deve essere inferiore al limite di utilizzo...

Il lavoro prende spunto dai risultati di un’analisi sperimentale del comportamento a fatica di giunzioni incollate di materiali compositi laminati di elevato spessore formati da strati di unidirezionale e di tessuto di fibra di carbonio. I giunti sono stati realizzati in modo tale da saggiare l’influenza della lunghezza di sovrapposizione (da 25,4...