Damage initiation and growth is investigated in single fiber (steel, PTFE, carbon fibers) composites. Full field measurement are performed while specimens are loaded to provide accurate and quantitative information about crack growth, displacements and strains in fibers’ vicinity.

The objective is to provide data to build and validate micromechanical models which consider damage of composite materials. L. Tabiai

Development of an analytical model considering the neighbourhood effect into polycrystals

The orientation of a grain is not the only parameter controlling its behavior. Its neighborhood has also a strong influence. Analytical models usually consider the grain immersed into a homogenized material which doesn’t allow to consider the neighborhood effect. After a finite element study in order to understand the mechanical behind this effect, an analytical model will be developed considering the neighborhood effect into polycrystals.  R. Bretin

Modelling the mechanical behavior of bio-soured polymers

The growing environmental awareness and the net increase in fossil energy sources costs are forcing the industries to seek more ecologically friendly materials for their products. Bio-sourced polymers have many advantages compared to synthetic. This project working on the design tools for these materials. The approach will rely on homogenization which aims at predicting composites effective properties based on microstructural information.  L. Yue

Modelling of the mechanical properties of 3D printed composite materials

Analytical models of the viscoelastic properties of short-fiber composite materials have been shown to be inaccurate for configurations obtained through 3D printing. This project aims to adapt methods based on the Fast Fourier Transform to create a fully numerical model, exhibiting the behaviour of real composite materials.  F. Sosa-Rey

Numerical Models Predicting the Hydrostatic Pressure into 3D Reinforced Composite Parts Manufactured by Resin Transfer Molding Process

The principal research objective of my PhD program is to compute the hydrostatic pressure inside the matrix of a 3D aerospace composite being manufactured by RTM. Models to predict overall temperatures, degree of cure and stresses are available and will be used to compute the local stresses, inside the matrix. This multi-scale strategy will bridge existing models developed by my research group to more advanced models that I will develop to compute local stresses. FFT based algorithms will be relied on to compute effective properties.  S. Himmiche

Homogenization and optimization of an orthopaedic insole

My project aims to develop homogenization and design tools to help orthoptists optimize patient specific orthopedic insoles. My attention will focus on honeycomb structures where the cells dimensions (width, height) can be locally varied to provide a functionally graded component whose mechanical response meets the therapeutic needs. Homogenization will enable a very rapid insole design optimization process where the honeycomb 3D structure will be replaced by computationally efficient equivalent plates. (This project is cooperation of Polytechnique, University of Montreal, CABOMA, Médicus and Medteq).  M. Moeini

Towards minimizing air leaks following pulmonary resection procedure: experimental biomechanical characterization of animal lungs with and without stapling

Stapling devices are used for removing tumors during resection surgeries. Staples affect the lung tissue and create post-operative air leaks. This study aims to experimentally characterize the biomechanical properties of the lung tissue under different physiological conditions to better understand the role of staples in the leak.  B. Bonnet

Multi-physics modeling of aerospace composites exposed to fire

Polymer matrix composites are reactive at high temperatures. However, certification requirements mandate that in some applications these components must act as firewalls (for instance, sandwich composites used as acoustic liners in turbofan engines). The physical processes influencing the material's thermal degradation must be identified to improve their fire resistance.The objective of this project is to model the degradation of a composite exposed to fire as a function of the fire conditions and material properties.  J. Langot

Modal analysis of a spinning disk in a dense fluid as a model for high head hydraulic turbines

In high head Francis turbines, RSI is an unavoidable source of excitation that needs to be predicted accurately. This project aims at the development of both an analytical and a numerical model for a rotating disk in a dense fluid, which accurately predicts the natural frequency split as well as the natural frequency drift. Additionally, the analytical model gives an explanation on the physical origin of the mode split phenomenon.  M. Louyot

Multiscale modeling of 3D woven composites

The objective of the research topic is to develop experimentally validated analytical and numerical multiscale modeling procedures accounting for viscoelastic behavior of 3D woven composites.  A. Trofimov

Direct and Inverse Methods to Analysis of Crack in Viscoelastic Fracture Problems Using a Meshfree Method

Considering the increasing use of polymers as a viscoelastic material, especially in different types of composites, it is important to understand and modeling the mechanical properties and fracture mechanism of these materials. To accomplish these goals, my project explores a new incremental formulation for viscoelastic materials, and then examines the Fracture mechanic property in these materials using the modified Meshfree methods. Therefore, the crack detection in these materials will be investigated using an inverse methods. Validation of these numerical methods will be verified not only with previous methods, but also at each step (modeling, fracture and crack detection in viscoelastic materials), I will compare my numerical results with designed experimental tests.  M. Hamidpour

Mode split prediction for rotating disks with flexible stator coupling

The dynamic behavior of hydraulic turbines is strongly influenced by the mode split: when rotor natural frequencies split and drift with rotating flow. This project follows the work from M. Louyot, in which he developed an analytical and a numerical model for a spinning disk in dense fluid. The objective is to extend them by integrating a radial gap and a stator, to consider the associated coupling.  L. Berthet