Guillaume Vermot Des Roches

NVH compliance issues related to brake squeal constitute nowadays a major cost in industry. Simulation remains very challenging, brake systems being complex assemblies operating in various conditions. Industrial applications rely on Complex Eigenvalue Analysis (CEA) whose recurrent correlation to squeal measurements makes it a relevant working basi...

Since tests only provide measurements at sensors, it is interesting to use models to estimate the response at all degree of freedom, correct measurement errors and possibly allow updating of model parameters. The paper gives an integrated perspective on methods developed by the control and structural dynamics communities and in particular methods s...

In brake FEM, model updating is often needed to improve the model accuracy and well describe problematic phenomena such as the squeal. To avoid performing a full model updating which is often time consuming, the use of the Minimum Dynamic Residual Expansion method is proposed to help building the updating strategy. The procedure proposed in this pa...

NVH compliance issues related to brake squeal constitute nowadays a major cost in industry. Simulation remains very challenging, brake systems being complex assemblies operating in various conditions. Industrial applications rely on Complex Eigenvalue Analysis (CEA) whose recurrent correlation to squeal measurements makes it a relevant working basi...

Structural health monitoring (SHM) is an emerging technology designed to automate the inspection process undertaken to assess the health condition of structures. The SHM process is classically decomposed into four sequential steps: damage detection, localization, classification, and quantification. This paper addresses damage type classification an...

In the presence of squeal, Operational Deflection Shapes (ODS) are classically performed to analyze behavior. A simple numeric example is used to show that two real shapes should dominate the response. This justifies an ad-hoc procedure to extract main shapes from the real brake time measurements. The presence of two shapes is confirmed despite var...

Structural Health Monitoring (SHM) can be defined as the process of acquiring and analyzing data from on-board sensors to evaluate the health of a structure. Classically, an SHM process can be performed in four steps: detection, localization, classification and quantification. This paper addresses damage quantification issue as a classification pro...

In presence of squeal, Operational Deflection Shapes (ODS) are classically measured to gain understanding of brake behavior. A simple numeric example is analyzed to justify the use of time-frequency analysis and shows that two real shapes should probably dominate the response. Using measurements on a real brake, this expectation is shown to hold ev...

Extending the bandwidth of validity of FEM models used in vibroacoustic design is a generic objective of model generation processes. Achieving this objective requires a critical review of both testing and modeling processes. Using the case study of an engine cradle, tools used to detect modal test inconsistencies are first illustrated. On the model...

Squeal occurrences are quite common in brakes in production and involve coupling of modes. Detailed understanding of vibration patterns typically requires FEM models updated using test results. The process used at Chassis Brakes International typically starts by updating components so that the main sources of variability are associated with junctio...

To be confident in the prediction capability of a model, verification and validation steps are classically performed. Verification checks that the model is properly solved. Since the model used are fairly standard, this is not issue for brake components. Validation checks the relation between model and experiments on actual structures. Here geometr...

Brake squeal impacts trains during station parking, generating over 110 dB at the wheel vicinity. This disturbance is a problem for commuters and employees working close to trains and limits exploitation times. The only adjustable parameter is here the brake pad, since it is the only part with frequent replacement regarding the railway equipment li...

The squeal noise generated by railway disk brakes is an everyday source of discomfort for the passengers both inside and outside the trains in stations. The development of silent brake components is needed and requires a better characterization and understanding of the phenomenon. This is the aim of the experimental and numerical investigations per...

25th International Conference on Noise and Vibration engineering (ISMA2012), LEUVEN, BELGIQUE, 17-/09/2012 - 19/09/2012

Brake squeal is a common noise problem encountered in the automotive industry. Higher friction coefficients and weight reduction recently led to higher vibration levels in the audible frequency range. This quality issue becomes economic due to penalties imposed to the brake supplier although no robust design method exists. The industrial practice t...

This paper presents advances in non-linear simulations for systems with contact-friction, with an application to brake squeal. A method is proposed to orient component structural modifications from brake assembly simulations in the frequency and time domains. A reduction method implementing explicitly component-wise degrees of freedom at the system...

Experimentally, modal damping is known to allow a relatively accurate representation of damping for wide frequency ranges. For transient simulation of full finite element models, viscous damping is very often the only formulation that is associated with an acceptable computation time. In the absence of a proper material damping model, it is common...

Robust design of silent brakes is a current industrial challenge. Braking systems enter in the more general context of unstable systems featuring contact friction interaction. Their simulation requires time integra-tion schemes usually not adapted to combination of large industrial models (over 600,000 DOF) and long simulations (over 150,000 time s...

Handling of large industrial mechanical assemblies implies structure interactions commonly modeled with contact formulations. In cases where component interfaces are discretized using non conforming meshes, classical contact solutions have difficulties producing correct contact pressure fields. The method presented in this paper gives a relevant me...

Handling of large industrial mechanical assemblies implies structure interactions commonly modeled with contact formulations. In cases where component interfaces are discretized using non conforming meshes, classical contact solutions have difficulties producing correct contact pressure fields. The method presented in this paper gives a relevant me...

Classically Component Mode Synthesis has been used to couple models from different sources (mixed test and analysis, different companies, different software, ...) or reduce models. The focus of this paper is on using component modes in a design cycle. Component modes are the natural representation in the lowest part design cycle. In NVH application...

L'utilisation de modèles éléments finis d'objets industriels complexes pose une problématique de compatibilité des maillages aux interfaces, en particulier dans le cas du contact. Cette incompatibilité génère des problèmes de convergence et de régularité des solutions. L'étude présentée ici étend le concept de la (1-e)-compatibilité introduite par...

This paper presents a modeling strategy employed to obtain converged results on long time simulation of complex finite element brake models. First a novel reduction method, adapted to models showing large interface DOF, is presented. The small finite element area in the vicinity of the contact is treated as fully non-linear and the remaining of the...