Marco Montemurro

Ecole Nationale Supérieure d'Arts et Métiers | ENSAM · Institut de Mécanique et Ingénierie de Bordeaux - I2M BORDEAUX

Variable Stiffness Composites (VSCs) have been lately proposed as a promising alternative to classical straight fibres composites where the variation of fibres orientation angle within the plane of the structure allows for a more general design of composite structures and consequent performances. Nevertheless, this new class of materials calls for...

Wire arc additive manufacturing an additive manufacturing process that allows producing large metal parts in a layer-by-layer fashion assuring a high deposition rate. However, the set of parameters that control the process leads to phenomena that are difficult to understand and predict. The work of this paper is to propose a metamodel based on basi...

Modern additive manufacturing processes enable fabricating architected cellular materials of complex shape, which can be used for different purposes. Among them, lattice structures are increasingly used in applications requiring a compromise among lightness and suited mechanical properties, like improved energy absorption capacity and specific stif...

Surrogate models are increasingly used in many sectors due to their ability to reproduce structural/system responses starting from numerical or experimental results. The main goal of a surrogate model is to preserve the same accuracy as the original model (within a certain interval) by considerably reducing the computational cost and, possibly, the...

This paper deals with topology optimisation (TO) problem with design-dependent loads. Specifically, the problem is formulated in the context of a special density-based TO algorithm wherein a non uniform rational basis spline (NURBS) entity is used to represent the topological descriptor, i.e., the pseudo-density field. In this context, TO problems...

This work examines the problem of oscillating boundaries in density-based topology optimisation algorithms based on B-spline hyper-surfaces. We compare recent developments in the different approaches proposed in the literature and attempt to find a relatively easy and robust method to obtain smooth optimal solutions by minimising the number of desi...

Variable Angle Tow (VAT) laminates offer a promising alternative to classical straight-fiber composites in terms of design and performance. However, analyzing these structures can be more complex due to the introduction of new design variables. Carrera's unified formulation (CUF) has been successful in previous works for buckling, vibrational, and...

In the last few years, the growing need of highly reliable and time-effective strategies to perform preliminary design of complex systems has led industries to adopt the Model Based System Engineering (MBSE) approach. In MBSE, systems are split into multiple sub-systems and the relevant physical phenomena are described via analytical or numerical m...

Among additive manufacturing processes, wire arc additive manufacturing (WAAM) is one of the most promising methods for manufacturing complex near-net-shape parts, as it allows the layer-by-layer deposition of welded material at a high deposition rate. However, this technology is highly dependent on deposition conditions and thermomechanical phenom...

The aim of this paper is twofold. On the one hand, it presents a methodology for the deterministic optimisation of a general class of variable-stiffness composite (VSC) structures, including a solution obtained by using laminæ with a curvilinear fibres-path and variable-thickness, by considering different design requirements under multiple load cas...

Variable Angle Tow (VAT) laminates offer a promising alternative to classical straight fiber composites in terms of design and performance. However, analyzing these structures can be more complex due to the introduction of new design variables. Carrera's Unified Formulation (CUF) has been successful in previous works for buckling, vibrational, and...

This work deals with the topology optimisation of structures made of multiple material phases. The proposed approach is based on non-uniform rational basis spline (NURBS) hyper-surfaces to represent the geometric descriptor related to each material phase composing the continuum, and an improved multiphase material interpolation (MMI) scheme to pena...

The model-based system engineering approach consists of assembling subsystems together to model a complete system. In this context, some functional blocks can have a considerable influence on the overall behaviour of the system. A preliminary identification of the influence of the subsystems on the output responses can help reducing the complexity...

This paper presents an original multi-level optimisation method for the design of composite structures integrating a global–local approach based on higher-order theories to assess the responses of the structure at each scale. The method offers a good balance between accuracy and computational costs. Unlike multi-level strategies available in the li...

This work deals with an experimental/numerical validation of the optimised topologies found through a special density-based topology optimisation (TO) method wherein the topological descriptor, i.e., the pseudo-density field, is represented through a non-uniform rational basis spline (NURBS) hyper-surface. The framework is that of multi-scale TO me...

This work deals with the multi-scale topology optimisation (TO) of multi-material lattice structures. The proposed approach is based on: non-uniform rational basis spline (NURBS) hyper-surfaces to represent the geometric descriptor related to each material phase composing the representative volume element (RVE), an improved multiphase material inte...

Handling blending constraint, a fundamental manufacturing requirement for the design of composite structures made of laminates with different thickness, is a hard task. A rigorous methodology to construct blended laminates regardless of the orientation value and of the position of the dropped plies within the laminates is presented and justified fr...

The paper concerns an experimental study on the wind pressures over the surface of a worldwide known Gothic Cathedral: Notre Dame of Paris. The experimental tests have been conducted in the CRIACIV wind tunnel, Prato (Italy), on a model of the Cathedral at the scale 1:200, reproducing the atmospheric boundary layer. Two types of tests have been con...

Recently, the necessity of reducing the probability of spread of viruses has fostered the creativity of engineers to develop tools that would allow actions of every-day life to be executed differently. Moreover, the maturity of the Fused Filament Fabrication (FFF) technology and the associated low costs has allowed creative solutions to be produced...

The paper concerns an experimental study on the wind pressures over the surface of a worldwide known Gothic Cathedral: Notre Dame of Paris. The experimental tests have been conducted in the CRIACIV wind tunnel, Prato (Italy), on a model of the Cathedral at the scale 1:200 reproducing the atmospheric boundary layer. Two types of tests have been cond...

Dear Colleagues, Given the recent interest in information technology and optimization methods for analyzing structures, this book aims to collect contributions on the topic of machine learning and control systems applied to the field of civil engineering for large and medium-scale structures. This Special Issue considers studies related to data-dri...

We homogenize the mechanical properties of a two-phase polymer composite, made of a polyurethane matrix containing porous spherical silicone-based inclusions, and designed to be used for wave control as a local resonant insulator. First we consider a homogenized energy for the spherical inclusions, an expression obtained by an explicit method. Then...

This work discusses three aspects of topology optimisation (TO) problems dealing with structural stiffness maximisation of anisotropic continua under mixed inhomogeneous Neumann–Dirichlet boundary conditions (BCs). Firstly, the total potential energy (TPE) is introduced as intuitive measure of the structural stiffness, instead of the work of applie...

A consistent energy-based cohesive zone model to simulate the mode I delamination behaviour of Fully-Uncoupled Multi-Directional (FUMD) laminates is presented in this study. The proposed energy-based approach allows determining a more general constitutive response of the cohesive interface to better match the experimental results. The constitutive...

Architected cellular materials (ACMs) with a periodic micro-structure are often employed in high-performance components obtained through additive manufacturing (AM) technologies due to their high specific strength and stiffness. ACMs are also used in thermal applications, where their high surface-to-mass ratio can be conveniently exploited to enhan...

This work proposes a theoretical/numerical framework for the topology optimisation of anisotropic architected cellular materials at different scales. In particular, the topological variable (i.e., the pseudo-density field) is defined at both the scale of the representative volume element (i.e., the unit cell) of the material and at the macroscopic...

This work presents a multi-scale design methodology for the deterministic optimisation of thin-walled composite structures integrating a global-local approach for the assessment of the buckling strength and a dedicated strategy to recover blended stacking sequences. The methodology is based on the multi-scale two-level optimisation strategy for ani...

This work presents a multi-scale design methodology for the deterministic optimisation of thin-walled composite structures integrating a global–local approach for the assessment of the buckling strength and a dedicated strategy to recover blended stacking sequences. The methodology is based on the multi-scale two-level optimisation strategy for ani...

In this paper, a multi-scale modeling approach is proposed to determine the undamped natural frequencies of lattice structures (LSs) and the related mode shapes. At the macroscopic scale, the LS is modeled as an equivalent homogenized medium whose elastic properties are determined through the strain energy-based homogenization technique. The accura...

A general theoretical and numerical framework for the strength and mass optimisation of variable-stiffness composite laminates (VSCLs) is presented in this work. The optimisation is performed in the context of the first-level problem of the multi-scale two-level optimisation strategy (MS2LOS) for VSCLs. Both the failure load maximisation problem (s...

This work proposes a general formulation of the design requirement on the structural displacements evaluated, simultaneously, at different points of the structure in the framework of a density-based algorithm for topology optimization. The algorithm makes use of Non-Uniform Rational Basis Spline (NURBS) hyper-surfaces to represent the pseudo-densit...

In Model-Based System Engineering (MBSE), some functional sub-systems can have a considerable influence on the overall system behaviour, whilst the effect of other ones can be neglected. Of course, the former requires a refined modelling approach, whilst the latter can be suitably represented by means of low-fidelity models (usually 0D models). Bei...

During this thematic school, I had the opportunity to present my thesis topic to an international audience. You can find this presentation at the following link: https://www.gdr-mascotnum.fr/media/etics2021_vuillod.pdf

This work deals with heat conduction problems formulation in the framework of a CAD-compatible topology optimization method based on a pseudo-density field as a topology descriptor. In particular, the proposed strategy relies, on the one hand, on the use of CAD-compatible Non-Uniform Rational Basis Spline (NURBS) hyper-surfaces to represent the pse...

In the present work, a physically-based finite element model simulating the compression moulding process of cork-based agglomerates is presented. The goal is the prediction of the pre-stress state due to the process and its influence on the macroscopic mechanical properties of the agglomerate. An ad-hoc algorithm simulating the mould filling phase...

An efficient surface reconstruction strategy is presented in this study, which is able to approximate non‐convex sets of target points (TPs). The approach is split in two phases: (a) the mapping phase, making use of the shape preserving method (SPM) to get a proper parametrization of each sub‐domain composing the TPs set; (b) the fitting phase, whe...

In this work, the Huber-Hencky-Von Mises criterion for isotropic materials is integrated into a special density-based algorithm for topology optimization (TO). The algorithm makes use of (a) Non-Uniform Rational Basis Spline (NURBS) hyper-surfaces to represent the pseudo-density field describing the topology of the continuum and (b) the well-known...

This work presents a new strategy for dealing with blending requirements in the composite structures design. Firstly, new analytical expressions of blending constraints, in the polar parameters space, are derived. Secondly, a dedicated numerical strategy for the recovery of blended stacking sequences is presented. The proposed approach is implement...

Innovative additive manufacturing processes open new design opportunities, in the field of periodic cellular shock absorbers. In this work, an experimental campaign on lattice samples has been developed and carried out for intermediate velocities. The geometries of the lattice samples used in the experimental tests are the result of a sensitivity a...

In this work, a multi-scale optimization strategy for lightweight structures, based on a global-local modelling approach is presented. The approach is applied to a realistic wing structure of a civil aircraft. The preliminary design of the wing can be formulated as a constrained optimization problem, involving several requirements at the different...

The development of additive manufacturing techniques for composite structures brought the emergence of a new class of composite materials: the variable angle-tow composites. Additive manufacturing of reinforced polymers allows the tow to be placed along a curvilinear path in each lamina. Accordingly, optimised solutions with enhanced properties can...

A general framework for the multi-scale topology optimisation (TO) of lattice structures (LSs) is presented in this work. The proposed method involves: Non-Uniform Rational Basis Spline (NURBS) hyper-surfaces to represent the pseudo-density field describing the LS representative volume element (RVE) topology, the Solid Isotropic Material with Penal...

This work deals with the multi-scale optimisation of composite structures by adopting a general global-local (GL) modelling strategy to assess the structure responses at different scales. The GL modelling approach is integrated into the multi-scale two-level optimisation strategy (MS2LOS) for composite structures. The resulting design strategy is,...

This work investigates two aspects linked to the nature of the feasible domain of anisotropic laminates. In the first part of the paper, proofs are given on the non-convexity of the feasible domain for full anisotropic and for membrane-orthotropic laminates, either in the lamination parameters space or in the polar parameters one. Then, adopting th...

This study presents a general approach for the multi-scale design of variable stiffness composites (VSCs). The first-level problem of the multi-scale two-level optimisation strategy (MS2LOS) is solved to determine the optimal distribution of the VSC stiffness properties at the macroscopic scale satisfying the requirements of the problem at hand. In...

The PrandtlPlane (PrP) aircraft wing-box least-weight design is presented in this work. This design problem is formulated as a constrained non-linear programming problem (CNLPP), by integrating static, buckling, fatigue and manufacturability requirements, under different loading conditions. The solution search is carried out by means of a suitable...

In this work, a design strategy for optimising thin-walled structures based on a global-local finite element (FE) modelling approach is presented. The preliminary design of thin-walled structures can be stated in the form of a constrained non-linear programming problem (CNLPP) involving requirements of different nature intervening at the different...

The formulation of Topology Optimisation (TO) problems related to dynamics is particularly challenging, due to some intrinsic difficulties of mathematical and numerical nature. This paper deals with the integration of specific physical quantities, such as eigen-frequencies and dynamic compliance, in a special TO algorithm, which combines a classica...

This study presents an original metamodelling technique based on Non-Uniform Rational Basis Spline (NURBS) hyper-surfaces. The proposed approach is able to fit general non-convex sets of target points (TPs) by extending the NURBS formalism to the N-dimensional (N-D) case. The shape of such a hyper-surface is tuned by several parameters: the number...

This study presents a new strategy to generate a surrogate model used for design purposes. The metamodel is based on Non-Uniform Rational Basis Spline (NURBS) hyper-surfaces and is able to fit non-convex sets of target points (TPs). The proposed method aims at determining all the parameters involved in the definition of the NURBS hyper-surface, i.e...

A numerical approach is proposed to assess the high cycle fatigue (HCF) strength of periodic cellular structures produced by Selective Laser Melting under multiaxial loads. The model is based on a general numerical homogenisation scheme and an explicit description of the Elementary Cell (EC) combined to an extreme values analysis making use of a fa...

This work deals with the problem of predicting the temperature-dependent equivalent elastic properties of cork-based composites by investigating the influence of the variability related to the material properties of cork. A dedicated numerical homogenisation approach based on the strain energy of periodic and a-periodic media has been developed to...

In this work, a multi-scale optimisation strategy for the preliminary design of composite structures involving design requirements at different scales, is presented. Such a strategy, denoted as GL-MS2LOS, has been formulated by integrating a dedicated global-local (GL) modelling approach into the multi-scale two-level optimisation strategy (MS2LOS)...

This work deals with the formulation of a general design requirement on the displacement of a continuum medium in the framework of a special density-based algorithm for topology optimization. The algorithm makes use of non-uniform rational basis spline hyper-surfaces to represent the pseudo-density field describing the part topology and of the well...

The design of an aerospace product is a long and complex process because of the various involved stakeholders and the necessary multidisciplinary activities. The associated product development plan is organized in major steps separated by milestones ending with the final delivery to the customer. The early steps define the high-level concepts that...

Additive manufacturing techniques such as selective laser melting (SLM) allow for manufacturing periodic porous titanium structures having complex geometry. The mechanical properties of these structures with different elementary cell (ECs) designs have been already studied in literature. However, their fatigue behaviour is not yet well understood. T...

This study deals with the problem of the least-weight design of a lattice structure subject to constraints of different nature. To face this problem, a general multi-scale optimisation procedure is proposed. This approach aims at optimising both global and local geometric parameters defining the shape of the representative volume element of the lat...

In this work, a new semi-automatic surface reconstruction procedure is proposed. The main goal of the method is to reconstruct the boundary surface of a triangulation obtained as a result of a topology optimisation calculation. The reconstruction problem is articulated in two main phases: tessellation mapping and surface fitting. The first phase co...

The formulation of failure criteria in the framework of a particular SIMP topology optimization (TO) algorithm exploiting the features of Non-Uniform Rational B-Splines (NURBS) hypersurfaces is proposed in this work. Tsai-Wu (TW), Tsai-Hill (TH) and Hoffman (Ho) phenomenological criteria that allow identifying the failure for anisotropic materials...

The PrP civil transport aircraft least-weight design strategy is presented in this work. The design problem is formulated as a constrained non-linear programming problem (CNLPP), by integrating static, buckling, fatigue and manufacturability requirements, under different loading conditions. The solution search is carried out by means of a suitable...

The recent development of new manufacturing techniques of composite structures, e.g., additive manufacturing (AM) techniques, allows for going beyond the classical design rules, thus leading the designer to find innovative and more efficient solutions like the variable angle-tow (VAT) composites. VAT composites allow taking advantage from the benef...

The problem of characterising the viscoelastic behaviour of a composite material at each pertinent scale is addressed in this paper. To this purpose, a dedicated multi-scale identification strategy (MSIS) exploiting the information restrained in the macroscopic non-linear dynamic response of the composite is developed. The MSIS aims to identify the...

Cork is a natural, recyclable and biodegradable industrially useful material with remarkable properties as lightness, excellent thermal and sound insulating properties mainly due to its honeycomb-like microstructure. Cork is extracted periodically, in a sustainable manner, from the outer bark of Quercus Suber L. and, depending on the type of final...

The last decades have been characterized by a growth of raw material demand, in particular due to the consumerism in developed countries and to the fast industrialization of emerging economies. Nowadays, with the aim to minimise the environmental impact due to the consistent reduction of primary resources, the main objective in the research field o...

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Structural solutions involving advanced composite materials are nowadays popular within the aeronautic industry. The excellent specific mechanical properties of these materials as well as the continuous manufacturing innovation of composite components allows for tailoring lightweight, efficient and reliable solutions. The design of a complex compos...