Mathieu Corus

• PhD
• Expert - Structural dynamics at Électricité de France (EDF)

The aim of this work is to propose an indicator, based on the info-gap approach, which assesses the robustness of the dynamic response of the model of a structure to lack of knowledge in the associated eigensolutions. The info-gap uncertainty model for the eigensolutions is constructed mode by mode based on a set of experimentally identified eigens...

This paper proposes a new approach to solve sparse linear saddle-point systems arising in large scale parameter estimation approach using energy functionals. The constraints of those systems involve kinematic constraints and sensors ones. The approach is based on a double projection of the generated saddle point system onto the nullspace of the con...

Important variations in response behaviors of power plant generators are observed in a population of nominally identical installations due to numerous and significant sources of variability. As a result, it proves to be extremely difficult to implement a predictive and reliable physics-based model. The present study attempts to leverage an existing...

Steam Generator (SG) tubes are subjected to fluid-elastic coupling forces and impacts against support plates & anti-vibration bars. Understanding their vibrations is crucial not only at the design stage, but also to optimize the SG maintenance policy and to lengthen the SG service life. The aim of our research is to provide a better understanding o...

The complex structural dynamic behaviour of turbo-alternators and their sub-assemblies must be well understood in order to insure their reliable and safe operation. In practice, important variations in response behaviours are observed in a population of otherwise nominally identical installations due to numerous and significant sources of variabili...

We are interested in constructing an uncertain computational model representing a family of structures and in identifying this model using a small number of experimental measurements of the first eigenfrequencies. The prior probability model of uncertainties is constructed using the generalized probabilistic approach of uncertainties which allows b...

In Pressurized Water Reactors of nuclear power plants, steam generators act as heat exchangers between primary and secondary coolant fluids. They consist of a bundle of U-tubes in which flows the primary coolant fluid. Several support plates guide these tubes vertically. Secondary coolant fluid flows along the U-tubes and passes through the space b...

Constrained viscoelastic damping treatments are fairly common in many applications but have not been industrially applied to aerospace engines. New engine designs tend to use BLISK (integrally bladed disks) machined from a single part and thus showing less friction damping than earlier designs. Constrained viscoelastic treatments are considered as...

Predicting the operating behaviour of a complex assembly including active components is a challenge, since accurate models of those components are rarely available. For example, the dynamic effects of coupled motor pumps on a nuclear power plant floor are of critical interest, but difficult to predict at the design phase. Indeed, manufacturers do n...

Predicting the in operation behaviour of complex assembly including active components is a challenge, since accurate models of those components are rarely available. For example, the dynamic effects of injectors bolted on a cylinder head are of critical interest, but difficult to predict in the design phase. Indeed, manufacturers do not provide a d...

The use of damping augmentation concepts is spreading, thus motivating the need for design and validation methodologies. The frequency and temperature dependence of viscoelastic materials pose the challenge of correlating the response at multiple operating conditions. The fact that each mode is affected differently by the viscoelastic treatments is...

A method designed to predict the effects of distributed modifications of structures is proposed here. This method is an evolution of the classical formulations, and distinguishes measurements and coupling points.Based on a coarse model of the structure to be modified, the proposed methodology tackles two major difficulties: efficient predictions fo...

Structural modification methods are designed to estimate the dynamic behaviour of a structure after a modification. This estimation is obtained by coupling an experimental model of the non modified structure and a numerical model of the modification For short delays and little resources, these methods, as presented in [1] for example, can be effici...

The paper seeks to analyze the influence of temperature on the dynamic behavior of bridges. The objective is to propose a model that can be used to analyze the validity of damage detection algorithms that seek to separate variations in the modal properties due to damage or temperature. One first shows how temperature changes generate thermal stress...

The paper revisits force identification methods. Rather than using the classical inversion of the estimated transfers, one prefers to use a local model to generate an estimator of the modal states. The pseudo inverse in the force estimation process is then limited to the well-conditioned inversion of the dynamic stiffness in modal coordinates. The...

This work deals with the improvements of methods devoted to estimate the influence of modifications on the dynamic behaviour of a structure (addition of stiffeners or masses, boundary condition changes). The input data for the method are an experimentally derived model of the initial structure and a numerical model of the modification. Based on a c...

Une méthode proposant d'estimer de l'effet de modifications structurales distribuées est proposée ici. Une évolution des formulations classiques permettant de prendre en compte la non coïncidence des points de mesure et des points de couplage est présentée. La mise en œuvre de la méthodologie à un exemple académique et un cas d'application industri...

A method designed to predict the effects of distributed mod- ifications of structures is proposed here. This method is an evolution of the classical formulation but uses distinct mea- surement and coupling points; it includes a smoothed expan- sion procedure and two indicators to estimate the quality of the result. An academic testbed and an indust...