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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Wed, 21 Feb 2024 16:14:30 GMT2024-02-21T16:14:30ZReview of model updating processes used for brake components
http://hdl.handle.net/10985/10921
Review of model updating processes used for brake components
MARTIN, Guillaume; BALMES, Etienne; VERMOT DES ROCHES, Guillaume; CHANCELIER, Thierry
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 geometry measurements and vibration tests are considered. The study seeks to perform a systematic review of how test quality is evaluated, and models are correlated and then updated. This will give a solid basis to define clear and easily used validations protocols for brake components where prediction of modes and their stability in the manufacturing process is often deemed critical. Updating the geometry before updating the material properties is shown to be very important: the residual error on frequencies is smaller and no bias is introduced in the estimated material properties. Proper pairing of modeshapes is important for broadband comparisons and the MAC criterion is used. Intermediate steps: experimental topology correlation using easy tools with accuracy evaluation, estimation of errors on test shapes, handling of mode crossing, are sources of errors that are analyzed. For the updating of contact properties, where many parameters may need update, the use of model reduction is shown to allow a major speed-up of parametric studies.
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/10985/109212015-01-01T00:00:00ZMARTIN, GuillaumeBALMES, EtienneVERMOT DES ROCHES, GuillaumeCHANCELIER, ThierryTo 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 geometry measurements and vibration tests are considered. The study seeks to perform a systematic review of how test quality is evaluated, and models are correlated and then updated. This will give a solid basis to define clear and easily used validations protocols for brake components where prediction of modes and their stability in the manufacturing process is often deemed critical. Updating the geometry before updating the material properties is shown to be very important: the residual error on frequencies is smaller and no bias is introduced in the estimated material properties. Proper pairing of modeshapes is important for broadband comparisons and the MAC criterion is used. Intermediate steps: experimental topology correlation using easy tools with accuracy evaluation, estimation of errors on test shapes, handling of mode crossing, are sources of errors that are analyzed. For the updating of contact properties, where many parameters may need update, the use of model reduction is shown to allow a major speed-up of parametric studies.Squeal measurement with 3D Scanning Laser Doppler Vibrometer: handling of the time varying system behavior and analysis improvement using FEM expansion
http://hdl.handle.net/10985/13856
Squeal measurement with 3D Scanning Laser Doppler Vibrometer: handling of the time varying system behavior and analysis improvement using FEM expansion
MARTIN, Guillaume; CHANCELIER, Thierry; VERMOT DES ROCHES, Guillaume; BALMES, Etienne
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 variations with wheel position and reproducibility tests. To obtain a high spatial density measurement, 3D Scanning Laser Doppler Vibrometer is interesting but leads to iterative measurements on a time-varying system. An algorithm to merge sequential measurement and extract main shapes is detailed. Even with a high-density 3D SLDV measurement, shapes characterizing the squeal event are still only known on accessible surfaces. Minimum Dynamic Residual Expansion (MDRE) is thus finally used to estimate motion on a full FE mesh which eases interpretation and highlights areas where the test and the model contain errors.
Mon, 01 Jan 2018 00:00:00 GMThttp://hdl.handle.net/10985/138562018-01-01T00:00:00ZMARTIN, GuillaumeCHANCELIER, ThierryVERMOT DES ROCHES, GuillaumeBALMES, EtienneIn 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 variations with wheel position and reproducibility tests. To obtain a high spatial density measurement, 3D Scanning Laser Doppler Vibrometer is interesting but leads to iterative measurements on a time-varying system. An algorithm to merge sequential measurement and extract main shapes is detailed. Even with a high-density 3D SLDV measurement, shapes characterizing the squeal event are still only known on accessible surfaces. Minimum Dynamic Residual Expansion (MDRE) is thus finally used to estimate motion on a full FE mesh which eases interpretation and highlights areas where the test and the model contain errors.The Component Mode Tuning (CMT) method. A strategy adapted to the design of assemblies applied to industrial brake squeal
http://hdl.handle.net/10985/10920
The Component Mode Tuning (CMT) method. A strategy adapted to the design of assemblies applied to industrial brake squeal
VERMOT DES ROCHES, Guillaume; REJDYCH, Gabriel; BALMES, Etienne; CHANCELIER, Thierry
Numerical prototyping is widely used in industrial design processes, allowing optimization and limiting validation costs through experimental testing. Industrial applications nowadays focus on the simulation of complex component assemblies that are generally mass produced. Coupling properties thus have to be modelled, updated and accounted for variability. For squeal applications, simulations still fail at robustly producing exploitable results due to the systems complexity, while experimentations are limited for diagnostic and design improvement. This paper presents a new application of the Component Mode Tuning, an efficient model reduction method adapted to quick system level reanalysis as function of component free modes, to study the effect of coupling. The impact of component coupling stiffness and coupling surface topology is thus assessed on a drum brake subassembly which design is sensitive to squeal. It is shown that significant system differences can come from coupling surface variations with patterns close to experimental observations. This emphases the need for refined analyses to control coupling in the perspective of robust modelling.
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10985/109202014-01-01T00:00:00ZVERMOT DES ROCHES, GuillaumeREJDYCH, GabrielBALMES, EtienneCHANCELIER, ThierryNumerical prototyping is widely used in industrial design processes, allowing optimization and limiting validation costs through experimental testing. Industrial applications nowadays focus on the simulation of complex component assemblies that are generally mass produced. Coupling properties thus have to be modelled, updated and accounted for variability. For squeal applications, simulations still fail at robustly producing exploitable results due to the systems complexity, while experimentations are limited for diagnostic and design improvement. This paper presents a new application of the Component Mode Tuning, an efficient model reduction method adapted to quick system level reanalysis as function of component free modes, to study the effect of coupling. The impact of component coupling stiffness and coupling surface topology is thus assessed on a drum brake subassembly which design is sensitive to squeal. It is shown that significant system differences can come from coupling surface variations with patterns close to experimental observations. This emphases the need for refined analyses to control coupling in the perspective of robust modelling.Updating and design sensitivity processes applied to drum brake squeal analysis
http://hdl.handle.net/10985/10922
Updating and design sensitivity processes applied to drum brake squeal analysis
MARTIN, Guillaume; BALMES, Etienne; VERMOT DES ROCHES, Guillaume; CHANCELIER, Thierry
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 junctions. A modeling strategy allowing the practical analysis of the impact of junctions is proposed and illustrated on the case of a drum brake assembly. As the level of uncertainty/design freedom is fairly large for junctions, the evolution of modal properties is difficult to interpret. The notion of component modes within a rigid assembly is thus introduced and shown to provide an appropriate interpretation of changes in a system with multiple modal crossings. The analysis of possible forced responses is finally shown to lead to relevant interpretation of possibly interesting designs or problematic instances of a variable component.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/109222016-01-01T00:00:00ZMARTIN, GuillaumeBALMES, EtienneVERMOT DES ROCHES, GuillaumeCHANCELIER, ThierrySqueal 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 junctions. A modeling strategy allowing the practical analysis of the impact of junctions is proposed and illustrated on the case of a drum brake assembly. As the level of uncertainty/design freedom is fairly large for junctions, the evolution of modal properties is difficult to interpret. The notion of component modes within a rigid assembly is thus introduced and shown to provide an appropriate interpretation of changes in a system with multiple modal crossings. The analysis of possible forced responses is finally shown to lead to relevant interpretation of possibly interesting designs or problematic instances of a variable component.Squeal complex eigenvalue analysis, advanced damping models and error control
http://hdl.handle.net/10985/10915
Squeal complex eigenvalue analysis, advanced damping models and error control
VERMOT DES ROCHES, Guillaume; CHIELLO, Olivier; BALMES, Etienne; LORANG, Xavier
Estimation of brake systems stability related to noise emission is part of the industry state-of-the-art for brake design. Improved assessment of stability would allow better NVH performance from early design stages thus reducing costs related to late redesign and testing. The prediction capability however remains challenged due to the complexity of brake noise phenomena. In particular, integration and resolution of complex systems with damping is a difficult task that is commonly overlooked. This paper proposes two ideas to improve stability estimation. From the solver side, a convergence indicator is proposed to quantify the convergence of the complex eigenvalues for subspace based methods. The error obtained can be directly used to enhance the computation subspace and a priori enhancement is suggested. From the modelling side, a damping strategy based on sub-assembly modal damping ratios is proposed allowing direct exploitation of test measurements or refined sub-assembly simulations for damping estimation. Sub-assembly damping can thus be accounted for at the system level including all possible effects like joint dissipation or composite materials.
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/10985/109152015-01-01T00:00:00ZVERMOT DES ROCHES, GuillaumeCHIELLO, OlivierBALMES, EtienneLORANG, XavierEstimation of brake systems stability related to noise emission is part of the industry state-of-the-art for brake design. Improved assessment of stability would allow better NVH performance from early design stages thus reducing costs related to late redesign and testing. The prediction capability however remains challenged due to the complexity of brake noise phenomena. In particular, integration and resolution of complex systems with damping is a difficult task that is commonly overlooked. This paper proposes two ideas to improve stability estimation. From the solver side, a convergence indicator is proposed to quantify the convergence of the complex eigenvalues for subspace based methods. The error obtained can be directly used to enhance the computation subspace and a priori enhancement is suggested. From the modelling side, a damping strategy based on sub-assembly modal damping ratios is proposed allowing direct exploitation of test measurements or refined sub-assembly simulations for damping estimation. Sub-assembly damping can thus be accounted for at the system level including all possible effects like joint dissipation or composite materials.MDRE: an efficient expansion tool to perform model updating from squeal measurements
http://hdl.handle.net/10985/16935
MDRE: an efficient expansion tool to perform model updating from squeal measurements
MARTIN, Guillaume; VERMOT DES ROCHES, Guillaume; BALMES, Etienne; CHANCELIER, Thierry
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 paper is evaluated on a disc brake system, using experimental measurements and the nominal model as input data. From experimental squeal measurements, two shapes are extracted and expanded on the current model. The evaluation of the residual error of model shows areas where the model is wrong and guides through the definition of sensitive parameters which need to be updated. Once the model is parameterized, a model reduction strategy is proposed for further computations to be performed in a time compatible with industrial processes. A parametric study is then achieved: the expansion is computed for all the combinations of the chosen parameters. It is finally possible to navigate through the expansion results for all the parameters, evaluate the evolution of the model accuracy and extract the best combination which improves the model representability.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10985/169352019-01-01T00:00:00ZMARTIN, GuillaumeVERMOT DES ROCHES, GuillaumeBALMES, EtienneCHANCELIER, ThierryIn 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 paper is evaluated on a disc brake system, using experimental measurements and the nominal model as input data. From experimental squeal measurements, two shapes are extracted and expanded on the current model. The evaluation of the residual error of model shows areas where the model is wrong and guides through the definition of sensitive parameters which need to be updated. Once the model is parameterized, a model reduction strategy is proposed for further computations to be performed in a time compatible with industrial processes. A parametric study is then achieved: the expansion is computed for all the combinations of the chosen parameters. It is finally possible to navigate through the expansion results for all the parameters, evaluate the evolution of the model accuracy and extract the best combination which improves the model representability.On the influence of geometry updating on modal correlation of brake components.
http://hdl.handle.net/10985/8095
On the influence of geometry updating on modal correlation of brake components.
FRANCA DE PAULA, Bruno; REJDYCH, Gabriel; CHANCELIER, Thierry; VERMOT DES ROCHES, Guillaume; BALMES, Etienne
In most industries dealing with vibration, test/analysis correlation of modal properties is considered a key aspect of the design process. The success of test/analysis methods however often show mixed results. The aim of this paper is to assess and answer some classical correlation problems in structural dynamics. First an investigation of correlation problems from tests is proposed. Tools based on the modal assurance criterion are presented to provide a deeper analysis of correlation and results improvement. In a second part, the need of FEM topology correlation and update is demonstrated, using an efficient morphing technique. Tolerances in the manufacturing process that are well accepted in design and production stages are shown to lead to significant degradation of the test/analysis correlation. An application to an industrial brake part is eventually presented, in an approach of correlation procedure automatization for recurrent use.
Sun, 01 Jan 2012 00:00:00 GMThttp://hdl.handle.net/10985/80952012-01-01T00:00:00ZFRANCA DE PAULA, BrunoREJDYCH, GabrielCHANCELIER, ThierryVERMOT DES ROCHES, GuillaumeBALMES, EtienneIn most industries dealing with vibration, test/analysis correlation of modal properties is considered a key aspect of the design process. The success of test/analysis methods however often show mixed results. The aim of this paper is to assess and answer some classical correlation problems in structural dynamics. First an investigation of correlation problems from tests is proposed. Tools based on the modal assurance criterion are presented to provide a deeper analysis of correlation and results improvement. In a second part, the need of FEM topology correlation and update is demonstrated, using an efficient morphing technique. Tolerances in the manufacturing process that are well accepted in design and production stages are shown to lead to significant degradation of the test/analysis correlation. An application to an industrial brake part is eventually presented, in an approach of correlation procedure automatization for recurrent use.Understanding friction induced damping in bolted assemblies through explicit transient simulation
http://hdl.handle.net/10985/8598
Understanding friction induced damping in bolted assemblies through explicit transient simulation
VERMOT DES ROCHES, Guillaume; BALMES, Etienne
The design of joints is seeing increased interest as one of the ways of controlling damping levels in lighter and more ﬂexible aeronautic structures. Damping induced by joint dissipation has been studied for more than a decade, mostly experimentally due to the difﬁculty of simulating large structures with non-linearities. Experimentally ﬁtted meta-models were thus used for damping estimation at design stage without a possible optimization. The aim of this paper is to demonstrate that damping estimation using local friction models is feasible and that it can be usable for design. The simulation methodology is based on an explicit Newmark time scheme with model reduction and numerical damping that can be compensated for the modes of interest. Practical simulation times counted in minutes are achieved for detailed models. The illustration on a lap-joint shows how simulations can be used to predict the amplitude dependence of modal damping, answer long standing questions such as “does the modeshape change?” or analyze the evolution of pressure ﬁelds during a cycle.
Wed, 01 Jan 2014 00:00:00 GMThttp://hdl.handle.net/10985/85982014-01-01T00:00:00ZVERMOT DES ROCHES, GuillaumeBALMES, EtienneThe design of joints is seeing increased interest as one of the ways of controlling damping levels in lighter and more ﬂexible aeronautic structures. Damping induced by joint dissipation has been studied for more than a decade, mostly experimentally due to the difﬁculty of simulating large structures with non-linearities. Experimentally ﬁtted meta-models were thus used for damping estimation at design stage without a possible optimization. The aim of this paper is to demonstrate that damping estimation using local friction models is feasible and that it can be usable for design. The simulation methodology is based on an explicit Newmark time scheme with model reduction and numerical damping that can be compensated for the modes of interest. Practical simulation times counted in minutes are achieved for detailed models. The illustration on a lap-joint shows how simulations can be used to predict the amplitude dependence of modal damping, answer long standing questions such as “does the modeshape change?” or analyze the evolution of pressure ﬁelds during a cycle.Expansion in structural dynamics : a perspective gained from success and errors in test/FEM twin building
http://hdl.handle.net/10985/23307
Expansion in structural dynamics : a perspective gained from success and errors in test/FEM twin building
BALMES, Etienne; MARTIN, Guillaume; VERMOT DES ROCHES, Guillaume; CHANCELIER, Thierry; THOUVIOT, Sylvain
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 seeking a trade-off between test and model error. The case of a measured brake squeal limit cycle is used to illustrate implementation details found to be important.
Sun, 01 May 2022 00:00:00 GMThttp://hdl.handle.net/10985/233072022-05-01T00:00:00ZBALMES, EtienneMARTIN, GuillaumeVERMOT DES ROCHES, GuillaumeCHANCELIER, ThierryTHOUVIOT, SylvainSince 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 seeking a trade-off between test and model error. The case of a measured brake squeal limit cycle is used to illustrate implementation details found to be important.Time/frequency analysis of contact-friction instabilities. Application to automotive brake squeal.
http://hdl.handle.net/10985/8232
Time/frequency analysis of contact-friction instabilities. Application to automotive brake squeal.
VERMOT DES ROCHES, Guillaume; BALMES, Etienne; PASQUET, Thierry; LEMAIRE, Rémi
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 steps). The paper ﬁrst discusses selection of the contact/friction model and adaptations of the integration scheme. The relation between the nominal steady state tangent modes and the system evolution over time is then evaluated. The time response shows a nearly periodic response that is analyzed as a limit cycle. It is shown that instantaneous dynamic stability predictions show stable/unstable transitions due to changes in the contact/friction state. These transitions are thought to give an understanding of the mechanism that limits levels for these self sustained vibrations. The concept is exploited to suggest novel ways to analyze complex modes.
Fri, 01 Jan 2010 00:00:00 GMThttp://hdl.handle.net/10985/82322010-01-01T00:00:00ZVERMOT DES ROCHES, GuillaumeBALMES, EtiennePASQUET, ThierryLEMAIRE, RémiRobust 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 steps). The paper ﬁrst discusses selection of the contact/friction model and adaptations of the integration scheme. The relation between the nominal steady state tangent modes and the system evolution over time is then evaluated. The time response shows a nearly periodic response that is analyzed as a limit cycle. It is shown that instantaneous dynamic stability predictions show stable/unstable transitions due to changes in the contact/friction state. These transitions are thought to give an understanding of the mechanism that limits levels for these self sustained vibrations. The concept is exploited to suggest novel ways to analyze complex modes.