References of "Bruls, Olivier"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailRelevance of early stretching in overhead athletes
Schwartz, Cédric ULg; Tubez, François ULg; Croisier, Jean-Louis ULg et al

Conference (2017, June 16)

Overhead athletes often develop, over time, a tightness of the posterior structures of the shoulder, which may be associated with injuries. Ten symptomatic (with pain) and ten asymptomatic players with a ... [more ▼]

Overhead athletes often develop, over time, a tightness of the posterior structures of the shoulder, which may be associated with injuries. Ten symptomatic (with pain) and ten asymptomatic players with a tight shoulder were compared and the effect of a self-applied stretching program was evaluated. Before and after the stretching program, pain and stiffness of the shoulder were evaluated. Our results demonstrate that risk factors for shoulder pain such as glenohumeral internal rotation deficit and total range of motion deficit may only be limited in symptomatic athletes. The mobility of the shoulder was significantly improved after the stretching program for both groups. Pain was reduced when present. Because of the limited differences between the symptomatic and asymptomatic athletes, clinicians may find it advantageous to initiate early prevention or rehabilitation programs. [less ▲]

Detailed reference viewed: 25 (3 ULg)
Full Text
Peer Reviewed
See detailInfluence of the laboratory context and the size of the markers set on the tennis serve evaluation
Tubez, François ULg; Forthomme, Bénédicte ULg; Croisier, Jean-Louis ULg et al

Conference (2017, June 15)

The purpose of this study was to identify the influence on the tennis serve evaluation of 1/ the test environment and 2/ the number of the markers placed of the player. Two different studies were ... [more ▼]

The purpose of this study was to identify the influence on the tennis serve evaluation of 1/ the test environment and 2/ the number of the markers placed of the player. Two different studies were performed. The first compared a 4 vs. 28 marker set in a laboratory the same day. The second compared a 4 markers test in a laboratory with a 4 markers test on an official tennis court one week apart. We observed similar results between the different tests of both studies. [less ▲]

Detailed reference viewed: 19 (0 ULg)
Full Text
Peer Reviewed
See detailFactors to be considered to perform a kinematic evaluation of the tennis serve
Tubez, François ULg; Forthomme, Bénédicte ULg; Croisier, Jean-Louis ULg et al

in Journal of Medecine and Science in Tennis (2017), 22

With the 2D video cameras and later the appearance of 3D measurement methods, the tennis serve has been increasingly studied. In order to improve the biomechanical evaluation of the tennis serve. Our goal ... [more ▼]

With the 2D video cameras and later the appearance of 3D measurement methods, the tennis serve has been increasingly studied. In order to improve the biomechanical evaluation of the tennis serve. Our goal is to provide a comprehensive view of the major factors of an evaluation protocol. [less ▲]

Detailed reference viewed: 40 (1 ULg)
See detailAlgorithm for Temporal Gait Analysis Using Wireless Foot-Mounted Accelerometers
Boutaayamou, Mohamed ULg; Denoël, Vincent ULg; Bruls, Olivier ULg et al

Book published by Springer (2017)

We present a new signal processing algorithm that extracts five gait events: heel strike, toe strike, heel-off, toe-off, and heel clearance from only two accelerometers attached on the heels of the ... [more ▼]

We present a new signal processing algorithm that extracts five gait events: heel strike, toe strike, heel-off, toe-off, and heel clearance from only two accelerometers attached on the heels of the subjects usual shoes. This algorithm first uses a continuous wavelet-based segmentation that parses the signal of consecutive strides into motionless periods defining relevant local acceleration signals. Then, the algorithm uses versatile techniques to accurately extract the five gait events from these local acceleration signals. We validated, on a stride-by-stride basis, the extraction of these gait events by comparing the results with reference data provided by a kinematic 3D analysis system and a video camera. The accuracy and precision achieved by the extraction algorithm for healthy subjects, the reduced number of accelerometer units required, and the validation results obtained, encourage us to further study this system in pathological conditions. [less ▲]

Detailed reference viewed: 67 (24 ULg)
Full Text
Peer Reviewed
See detailAeroservoelastic Simulations for Horizontal Axis Wind Turbines
Prasad, Chandra Shekhar ULg; Chen, Qiong Zhong; Bruls, Olivier ULg et al

in Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy (2017), 231(2), 103-117

This paper describes the development of a complete methodology for the aeroservoelastic modeling of horizontal axis wind turbines at the conceptual design stage. The methodology is based on the ... [more ▼]

This paper describes the development of a complete methodology for the aeroservoelastic modeling of horizontal axis wind turbines at the conceptual design stage. The methodology is based on the implementation of unsteady aerodynamic modeling, advanced description of the control system and nonlinear finite element calculations in the SWT wind turbine design package. The aerodynamic modeling is carried out by means of fast techniques, such as the Blade Element Method and the unsteady Vortex Lattice Method, including a free wake model. The complete model also includes a description of a doubly fed induction generator and its control system for variable speed operation. The SWT software features a non-linear finite element solver with multi-body dynamics capability. The full methodology is used to perform complete aeroservoelastic simulations of a realistic 2MW wind turbine model. The interaction between the three components of the approach is carefully analyzed and presented here. [less ▲]

Detailed reference viewed: 61 (18 ULg)
Full Text
See detailDesign of an experimental set-up to analyse compliant mechanisms used for the deployment of a panel
Dewalque, Florence ULg; Bruls, Olivier ULg

in Proceedings of the 14th European Conference on Spacecraft Structures, Materials and Environmental Testing (ECSSMET) (2016, September 30)

Due to their high complexity, compliant mechanisms require high-fidelity mechanical models to reach a detailed understanding of their characteristics and predict their actual behaviour in various ... [more ▼]

Due to their high complexity, compliant mechanisms require high-fidelity mechanical models to reach a detailed understanding of their characteristics and predict their actual behaviour in various situations. This work focuses on tape springs which are used as an alternative to common mechanisms composed of kinematic joints. They present several assets such as, among others, passive deployment and self-locking, but they are characterised by a highly nonlinear behaviour including buckling, the formation of folds and hysteresis. An experimental set-up is then designed to gather information on these phenomena, while in parallel an equivalent finite element model is developed. Quasi-static and dynamic tests are performed, as well as small amplitude vibration tests and large amplitude deployments in order to collect data in a broad variety of cases. The post-processing of the numerous raw data shows, with the help of statistical considerations, the good quality of the acquisitions. Finally, the finite element model proves to be fairly well correlated to the experimental results. [less ▲]

Detailed reference viewed: 60 (7 ULg)
Full Text
Peer Reviewed
See detailGait pattern of healthy old people for fast walking condition
GILLAIN, Sophie ULg; Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg et al

in Gerontechnology (2016, September)

Detailed reference viewed: 63 (17 ULg)
Full Text
Peer Reviewed
See detailGait pattern of healthy old people for dual task walking condition
GILLAIN, Sophie ULg; Boutaayamou, Mohamed ULg; Schwartz, Cédric ULg et al

in Gerontechnology (2016, September)

Detailed reference viewed: 53 (16 ULg)
Peer Reviewed
See detailOn the compatibility equations in geometrically exact beam finite element
Sonneville; Bruls, Olivier ULg; Bauchau, Olivier A.

in Proceedings of the 12th International Conference on Multibody Systems, Nonlinear Dynamics and Control (MSNDC) within the ASME/IDETC/CIE Conference (2016, August)

This paper discusses the compatibility equations which relate the velocity field and the strain field in geometrically exact beam theory. The analysis is carried out in the context of intrinsic equations ... [more ▼]

This paper discusses the compatibility equations which relate the velocity field and the strain field in geometrically exact beam theory. The analysis is carried out in the context of intrinsic equations, namely the dynamic equilibrium equations are formulated in terms of velocity and strain only. In addition to the well established objectivity and path-independence requirements of the spatial discretization, these compatibility equations show that a consistent spatial interpolation of the velocity field should depend on the curvature of the beam, including initial curvature and curvature from the deformation, and it is shown that this consistency is connected to the ability of the element to represent rigid body motion velocity. A two node interpolation scheme is studied and it appears that, as the element gets smaller under mesh refinement, the effect of this dependency reduces, leading eventually to the classical linear shape functions. [less ▲]

Detailed reference viewed: 91 (5 ULg)
Full Text
Peer Reviewed
See detailModelling of multibody systems in the local frame
Bruls, Olivier ULg; Sonneville, Valentin

in Proceedings of the 24th International Congress of Theoretical and Applied Mechanics (ICTAM) (2016, August)

A local frame finite element approach is proposed to describe the kinematics of a flexible multibody system, derive the equations of motion and solve them numerically. It is argued that this approach ... [more ▼]

A local frame finite element approach is proposed to describe the kinematics of a flexible multibody system, derive the equations of motion and solve them numerically. It is argued that this approach leads to reduced geometric nonlinearities and improved computational efficiency. [less ▲]

Detailed reference viewed: 66 (8 ULg)
See detailOptimal design of flexible mechanisms using a generalized equivalent static load method
Tromme, Emmanuel; Sonneville, Valentin; Guest, James K. et al

in Proceedings of the 24th International Congress of Theoretical and Applied Mechanics (2016, August)

The equivalent static load (ESL) method is a powerful approach to solve dynamic response structural optimization problems. The method transforms the dynamic response optimization into a static response ... [more ▼]

The equivalent static load (ESL) method is a powerful approach to solve dynamic response structural optimization problems. The method transforms the dynamic response optimization into a static response optimization under multiple load cases. The ESLs are defined based on the transient analysis response whereupon all the standard techniques of static response optimization can be used. In the last decade, the ESL method has been applied to perform structural optimization of flexible components of mechanical systems modeled as multibody systems. This method considers the optimization of isolated component during the static response optimization. The present research proposes a generalized ESL method accounting for the entire system during the static response optimization, which enables to formulate the constraints with respect to the mechanism and not restricted to the individual components. The proposed method relies on a Lie group formalism which has appealing properties to derive efficiently the ESL. Examples validate the method. [less ▲]

Detailed reference viewed: 61 (2 ULg)
Full Text
See detailReproducibility of a tennis serve protocol
Tubez, François ULg; FORTHOMME, Bénédicte ULg; Croisier, Jean-Louis ULg et al

Conference (2016, July 08)

INTRODUCTION Serve in modern tennis game is a real offensive weapon for players. In kinematic analysis, it is the most studied stroke of this game because it is the only stroke played in a closed skill ... [more ▼]

INTRODUCTION Serve in modern tennis game is a real offensive weapon for players. In kinematic analysis, it is the most studied stroke of this game because it is the only stroke played in a closed skill. Players have a maximum of control on this stroke. It is unclear whether 3D kinematic tests are reproducible for the same player under identical conditions and if a familiarization session is necessary. In practice, with professional players, who have little time available to perform tests, familiarization sessions are difficult. The aim of our study is to measure the reproducibility of a 3D serve protocol test. METHODS Nine tennis players (righties, regional level, 20 ± 2 years) were asked to hit first flat serves in a 1 m² area placed on the "T" zone of deuce diagonal of the tennis court. Two identical tests are performed one week apart. For each test, we selected the three best serves of the 25 trials (with the highest speed and the highest accuracy). Kinetics measurements were performed using a 3D analysis system (Codamotion), a force platform (Kistler) and a radar gun. 28 markers were placed on the players’ bodies to measure kinematics of the movements: ankles, knees, hips, trunk, shoulder, elbow and wrist dominant side. We measured ball speed, leg drive, linear velocity of the racket and joints, joints range of motion and maximum angular velocities at different positions (armed, maximum external rotation and impact) (1). RESULTS All analyzed parameters (linear speeds of racket and joints, leg drive force, joint angles and angular velocities) are reproducible with exception of a small part of them. Our study shows that 5,7% (7 of 122 measurements) joint position parameters and 8,3% (4 of 48 measures) angular velocity parameters are not reproducible from a session to another. DISCUSSION Various errors sources encountered in 3D analysis can justify the presence of non-reproducible parameters (2-3). However, after this work, we can state that the established protocol provides reproducible results when analyzing the tennis serve. [less ▲]

Detailed reference viewed: 73 (4 ULg)
Full Text
See detailNonlinear analysis of compliant mechanisms: application to tape springs
Dewalque, Florence ULg; Bruls, Olivier ULg

Poster (2016, July 07)

Brief summary of the mechanical behaviour of tape springs. Main results obtained by the means of finite element models. Description of the experimental set-up and results. See the extended abstract for ... [more ▼]

Brief summary of the mechanical behaviour of tape springs. Main results obtained by the means of finite element models. Description of the experimental set-up and results. See the extended abstract for more details. [less ▲]

Detailed reference viewed: 34 (5 ULg)
Full Text
See detailInverse dynamics of a flexible 3D robotic arm for a trajectory tracking task
Lismonde, Arthur ULg; Sonneville, Valentin; Bruls, Olivier ULg

Scientific conference (2016, May 30)

Detailed reference viewed: 36 (9 ULg)
Full Text
Peer Reviewed
See detailNonlinear Interpolation on Manifold of Reduced Order Models in Magnetodynamic Problems
Paquay, Yannick ULg; Bruls, Olivier ULg; Geuzaine, Christophe ULg

in IEEE Transactions on Magnetics (2016), 52(3), 1-4

Detailed reference viewed: 111 (37 ULg)